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Lignin as a biopolymer, has drawn much attention owing to its renewable nature, biodegradability, easy availability, and excellent stability. Water-borne polyurethane (WPU)-based coatings have been contributing to sustainable and eco-friendly practices offer a straightforward avenue for the value-added utilization of lignin. With the alarming rise in death rates attributed to skin diseases due to ultraviolet (UV) radiation damage, researchers have been actively searching for sustainable coating processes that enhance the UV protective capabilities of fabrics. In this paper, a facile strategy was reported for fabricating an environment friendly, mechanically durable, and UV protective biodegradable polylactic acid (PLA) spunlace nonwoven fabrics (SNFs) using lignin/WPU composite coatings. Lignin/WPU coating pastes were prepared using five different recipes including different lignin concentrations (0.5, 1.0, 1.5, and 2.0 wt.%) and coated on PLA SNFs via an applicator and thermally cured. Mechanical properties (e.g. tensile strength and abrasion resistance) and UV protection factor (UPF) values of fabrics were investigated. The coating films were characterized by Fourier Transform-Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analysis. Lignin/WPU coated SNFs showed excellent UV protection performance and UPF values were obtained above 100 for all formulations. Lignin/WPU coatings provided an improving effect on the tensile strength and abrasion resistance performances of coated SNFs compared to uncoated SNFs. This work provides a simple and efficient strategy for preparing environmentally friendly lignin/WPU coatings, which are promising for application in the textile industry. [ABSTRACT FROM AUTHOR]

Acacia gum (AG), a polysaccharide biopolymer, has been adopted to improve the strength of three cohesive soils by subjecting them to diverse environmental aging conditions. Being a polysaccharide and a potentially sustainable construction material, the AG yielded flexible film-like threads after 48 h upon hydration, and its pH value of 4.9 varied marginally with the aging of the stabilized soils. The soil samples for the geotechnical evaluation were subjected to wet mixing and were tested under their Optimum Moisture Content (OMC), as determined by the light compaction method. The addition of AG modified the consistency indices of the soils due to the presence of hydroxyl groups in AG, which also led to a rise in OMC and reduction in Maximum Dry Unit weight (MDU). The Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) were determined under thermal curing at 333 K as well as on the same day of sample preparation. The least performing condition of the soil's CBR was evaluated under submerged conditions after allowing the AG-stabilized specimens to air-cure for a period of 1 week. The UCS specimens tested after 7 days were subjected to the initial 7 days of thermal curing at 333 K. A dosage of 1.5% of AG yielded the UCS of 2530 kN/m2 and CBR of 98.3%, respectively, for the low compressible clay (LCC) after subjecting the sample to 333 K temperature for 1 week. The viscosity of the AG was found to be 214.7 cP at 2% dosage. Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and average particle size determination revealed the filling of pores by AG gel solution, adsorption, and hydrogen bonding, which led to improvements in macroproperties. [ABSTRACT FROM AUTHOR]

New trifunctional polybenzoxazines were developed and utilized as a high-potent coating material for superhydrophobic cotton fabrics and mild steel corrosion protection applications. New trifunctional benzoxazines resin have been synthesized using trihydroxytriphenylmethane (TTM) with dimethylaminopropylamine (dmapa), 1-(3-aminopropyl)imidazole (ipa) and aminoethoxyethanol (aee) as amine sources with paraformaldehyde through Mannich condensation. The structural confirmation of synthesized benzoxazines was ascertained by spectral studies. The ring opening polymerization of TTM-Bzs was studied using DSC analysis. All the three TTM-Bz monomers show curing temperature lower than 210°C. The thermo-stability and water contact angle (WCA) of polybenzoxazines were studied using thermogravimetric analysis and goniometer, respectively. Among the TTM-PBz studied, the poly(dmapa) exhibit better thermo-stability and hydrophobic behavior when compared to rest of the synthesized polybenzoxazines. Poly(TTM-dmapa)-coated cotton fabric exhibits the superhydrophobic behavior and mild steel (MS)-coated specimen possesses the higher charge transfer resistance value of 3.47 × 107 Ω cm². It was also inferred that all the TTM-PBz-coated MS specimens exhibit higher corrosion protection behavior as well as good thermo-stability and hydrophobic nature. Further, the obtained results suggested that these materials can be suitably exploited for hydrophobic anticorrosion applications with improved performance and enhanced longevity. [ABSTRACT FROM AUTHOR]

Visible light-based volumetric additive manufacturing (VAM) technology has recently enabled rapid 3D printing of optically transparent resins in a single step. There is now strong interest in extending the design space of VAM to include opaque, scattering and composite materials. Microwave energy can penetrate more deeply than visible light into a broader family of materials. For microwaves to be useful for VAM, however it is necessary to have a fundamental understanding of material dielectric properties, microwave field propagation and localization. Here we present a multi-physics microwave beam formed-thermal diffusion model that addresses these needs. The model demonstrates its ability to optimize power delivery and curing time to obtain better thermal control. We validate the model with a proof-of-concept single-antenna experimental system operating at 10 GHz that is able to cure a wide variety of materials, including both optically translucent and opaque epoxy resins loaded with conductive additives with a minimum curing spot of 5 mm. While available microwave hardware operating at 40 Watt power cures the resins in 2.5 min, the model estimates the ability to cure in as less as 6 s at 1 Kilowatt power levels. This computational model and experiments lay the foundation for a future multi-waveguide microwave-based VAM system.

Acacia gum (AG), a polysaccharide biopolymer, has been adopted to improve the strength of three cohesive soils by subjecting them to diverse environmental aging conditions. Being a polysaccharide and a potentially sustainable construction material, the AG yielded flexible film-like threads after 48 h upon hydration, and its pH value of 4.9 varied marginally with the aging of the stabilized soils. The soil samples for the geotechnical evaluation were subjected to wet mixing and were tested under their Optimum Moisture Content (OMC), as determined by the light compaction method. The addition of AG modified the consistency indices of the soils due to the presence of hydroxyl groups in AG, which also led to a rise in OMC and reduction in Maximum Dry Unit weight (MDU). The Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) were determined under thermal curing at 333 K as well as on the same day of sample preparation. The least performing condition of the soil’s CBR was evaluated under submerged conditions after allowing the AG-stabilized specimens to air-cure for a period of 1 week. The UCS specimens tested after 7 days were subjected to the initial 7 days of thermal curing at 333 K. A dosage of 1.5% of AG yielded the UCS of 2530 kN/m2 and CBR of 98.3%, respectively, for the low compressible clay (LCC) after subjecting the sample to 333 K temperature for 1 week. The viscosity of the AG was found to be 214.7 cP at 2% dosage. Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and average particle size determination revealed the filling of pores by AG gel solution, adsorption, and hydrogen bonding, which led to improvements in macroproperties.

The technique of mass soil stabilization using alternative binders to Portland cement (PC) has been used successfully in the past. However, knowledge gaps exist regarding the design of these binders. Ground-granulated blast furnace slag (GGBS) has been widely used as a substitute for PC; however, it requires an alkaline activator (e.g. lime and PC) to promote pozzolanic reaction and strength enhancement. A candidate that presents a less energy-intensive manufacturing and carbon footprint is carbide lime (CL), a by-product of acetylene gas production, rich in Ca(OH)2. The main problem with the pozzolanic binder in the stabilization technique is its slow reaction kinetics and the long time required for laboratory-scale investigations before in situ application. Therefore, this research presents a dosing study of a ternary binder (TB) comprising CL, GGBS and PC type III (CEM-III) to mass-stabilize a clayey organic soil using thermal curing as an innovative technique to improve the feasibility of laboratory-scale investigations. The effects of binder composition and thermal curing time on the evolution of strength, stiffness, mineralogy, and microstructure were determined. The results, supported by a statistical analysis (ANOVA) and by a multivariate regression analysis (MRA), have shown that the new TB produced a superior mechanical response to soil samples stabilized exclusively with CEM-III. This was evidenced by a less porous microstructure (more reaction products) and mainly the formation of a C–A–S–H gel, as a product of CEM-III hydration and alkaline activation of GGBS (blended cement), whereby the CL content played a key role for the development of the long-term pozzolanic reaction. [ABSTRACT FROM AUTHOR]

In this study, hydroxyapatite (HA) was surface modified with silane coupling agent. The modified HA was named HA-APTES, and its structure was analyzed. Hydroxyapatite modified urea-formaldehyde resin (HUF) were prepared by adding different amounts of HA-APTES in the synthesis process. The properties of the resin were tested to determine the optimal addition amount of HA-APTES, and the thermal curing properties of resins were investigated by differential scanning calorimetry. The results suggested that HA-APTES has excellent formaldehyde-reducing effect and can significantly improve the wet shear strength of the resin, and the optimal addition amount of HA-APTES is 3%. Notably, compared to UF resin, the peak temperature and activation energy (Eα) of HUF resin are increased, the reaction sites are increased, and the network structure is complicated. [ABSTRACT FROM AUTHOR]

Copyright of Journal of East China University of Science & Technology is the property of Journal of East China University of Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fly Ash Comprehensive Utilization is the property of Hebei Fly Ash Comprehensive Utilization Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of six slag dosages of 0%, 10%, 20%, 30%, 40% and 50% (mass fraction, the same below) on the shrinkage of fly ash-based geopolymer (FAGP) concrete during thermal curing process were studied with digital image correlation (DIC) method. The compressive strength of concrete and paste after thermal curing were tested, and the microscopic mechanism was analyzed by combining simultaneous thermal analysis (TG-DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that with the increase of slag content, the total shrinkage and shrinkage rate of FAGP first decrease and then increase, the compressive strength increases first and then decreases, the hydration degree increases, and the number of microcracks increases. When the slag content is 40%, FAGP concrete has the smallest shrinkage and the highest compressive strength. When the slag content is low, the hydration degree of the geopolymer is small, and there are fewer microcracks. At this time, the main reason for the shrinkage of the geopolymer is the lower elastic modulus at the beginning of thermal curing. When the slag content is high, the hydration degree of the geopolymer is high, and there are many microcracks. At this time, the shrinkage deformation of the geopolymer is mainly caused by a large degree of chemical reaction. [ABSTRACT FROM AUTHOR]

Limitations in existing anion exchange membranes deter their use in the efficient treatment of industrial wastewater effluent. This work presents an approach to fabricating novel anion-conducting membranes using epoxy resin monomers like hydrophobic or hydrophilic diglycidyl ether and quaternized polyethyleneimine (PEI). Manipulating the diglycidyl ether nature, the quantitative composition of the copolymer and the conditions of quaternization allows control of the physicochemical properties of the membranes, including water uptake (20.0–330%), ion exchange capacity (1.5–3.7 mmol/g), ionic conductivity (0.2–17 mS/cm in the Cl form at 20 °C), potentiostatic transport numbers (75–97%), as well as mechanical properties. A relationship was established between copolymer structure and conductivity/selectivity trade-off. The higher the quaternized polyethyleneimine, diluent fraction, and hydrophilicity of diglycidyl ether, the higher the conductivity and the lower the permselectivity. Hydrophobic diglycidyl ether gives a much better conductivity/selectivity ratio since it provides a lower degree of hydration than hydrophilic diglycidyl ether. Different mesh and non-woven reinforcing materials were also examined. The developed membranes demonstrate good stability in both neutral and acidic environments, and their benchmark characteristics in laboratory electrodialysis cells and batch-mode dialysis experiments are similar to or superior to, commercial membranes such as Neosepta© AMX, FujiFilm© Type1, and Fumasep FAD-PET.

Low temperature belite cements are produced using techniques that stabilize the more reactive high temperature polymorphs of dicalcium silicate (C2S) to improve early strength, but the effect of curing conditions on them is not well studied. The focus of this work is to assess the improvement of their early strength in different curing conditions. During the synthesis of the cements at 1000 ºC, the more reactive polymorphs, -C2S and ?-C2S, were stabilized using gypsum and hydrothermal treatment with potassium hydroxide. The phase composition of the synthesized cements was analysed using X-ray powder diffraction. The morphology and elemental composition of the C2S crystals and hydrated pastes was determined using a scanning electron microscope equipped with an energy-dispersive X-ray system. Mortar samples were cured in different conditions that include hot air and hot water curing at 60 ºC and 90 ºC. The 28-day strength development, capillary water porosity, water absorption, and ultrasonic pulse velocity were tested. The formation of hydration products and strength was dependent on the type of C2S polymorph. Curing at elevated temperatures improved the transport properties of mortars. Samples cured at 90 ºC in hot air obtained the highest early strength. The presence of -C2S and elevated curing temperatures significantly improve the early strength of the mortar samples. ABSTRAK: Simen belite suhu rendah dihasilkan melalui teknik menstabilkan reaktif polimof dikalsium silikat (C2S) bersuhu tinggi bagi meningkatkan kekuatan awal, tetapi kesan keadaan pengawetan ke atasnya tidak dikaji dengan baik. Fokus kerja ini adalah bagi menilai peningkatan kekuatan awal pada keadaan pengawetan berbeza. Sintesis simen pada suhu 1000 ºC, iaitu pada polimof lebih reaktif, -C2S dan ?-C2S, telah distabilkan menggunakan rawatan gipsum dan hidroterma dengan kalium hidroksida. Fasa komposisi simen tersintesis dianalisa menggunakan pembelauan serbuk sinar-X. Komposisi morfologi dan unsur kristal C2S dan pes terhidrat ditentukan menggunakan pengimbas mikroskop elektron yang dilengkapi sistem sinar-X penyebar tenaga. Sampel mortar telah diawetkan dalam keadaan berbeza termasuk pengawetan udara panas dan air panas pada suhu 60 ºC dan 90 ºC. Perkembangan kekuatan keliangan kapilari air, penyerapan air, dan halaju nadi ultrasonik telah diuji pada hari ke 28. Pembentukan produk penghidratan dan kekuatan adalah bergantung kepada jenis polimof C2S. Pengawetan pada suhu tinggi meningkatkan sifat pengangkutan mortar. Sampel yang diawet pada 90 ºC dalam udara panas memperoleh kekuatan awal tertinggi. Kehadiran -C2S dan suhu pengawetan tinggi dengan ketara meningkatkan kekuatan awal sampel mortar.

Regarding the significance of binder quantity, alkali activator molarities, and thermal curing, this work was utilized to geopolymerize with a potassium-based alkaline activator to strengthen soils. Five different molarities of palm oil fuel ash (POFA) in four different amounts were utilized to activate the clayey soil. POFA admixtures have been used to test soils. The results showed that for mixtures with 10 and 12.5 molarities, the unconfined compressive strength (UCS) with 15 % and 20 % of POFA was stronger. Comparing the strengths of the blends with various POFA amounts and concentration molarities allowed for this determination. To increase the strength, it is crucial to consider how the geopolymerization method's temperature and curing time affect the UCS of the soil-POFA mixture with and without fibers. The UCS of the treated soil mixtures was changed by heating at 30, 50, 70, and 90 °C. The outcomes demonstrate that increasing the curing temperature will hasten the alkaline activation process. After seven days of heating, the treated soil specimens with and without fibers exhibit the best mechanical properties at a healing temperature of about 70 °C, with compressive strengths of 16.7 and 11.4 MPa. The interaction between the geo-polymeric matrix and the fiber surface, the molarities of the alkaline solution, and the heating temperature were the most important aspects, according to an investigation of the microstructures, in improving the behavior of the reinforced mixes. By offering an efficient approach for increasing the qualities of soil treated by the alkali activation of POFA through the inclusion of glass fibers with adequate molarities of reagent and cure heating temperature, the current work offers new insights into soil stabilization operations. This has advantages over conventional calcium-based binders due to their emission of carbon dioxide during manufacture, which is one of the major causes of global warming.

Silver Epoxy reinforcement is pivotal to enhance the adhesive strength of Graphene nanoplatelets (GNP) on the substrate. This experimental study seeks to scrutinize the effects of Silver Epoxy reinforced GNP functionalized surface on the heat transfer of pool boiling. Three different GNP-based coatings are analyzed: simple GNP, uncured GNP reinforced with Silver Epoxy, and cured GNP reinforced with Silver Epoxy, all applied to copper substrate. For each coating, the surface morphology, chemical bonding, and wettability are examined. Under a heat flux of 550 kW/m2, the experimentally derived heat transfer coefficient improves by 194%, 36%, and 77% respectively on pristine GNP, uncured GNP/Epoxy, and cured GNP/Epoxy compared to the bare copper surface. The epoxy reinforcement weakens the exceptional boiling improvement achieved by a GNP functionalized surface. Although the thermal curing process turns the GNP/epoxy coating from hydrophobic to hydrophilic and recovers partly the level of boiling enhancement, the biphilicity of GNP tends to dominate boiling heat transfer enhancement by enhancing the bubble dynamics. The hydrophilicity has a subordinate effect by re-wetting the dry spots and preventing the vapour blanket. Silver Epoxy reinforcement significantly enhances the adhesive strength of GNP on a substrate but at the expense of boiling heat transfer enhancement.

The advantages that plastic‐based composites provide over epoxy‐based composites have catalyzed interest in the former in recent years. Polystyrene, a common packaging plastic, has been used for the production of composites. However, its hydrophilicity and curing duration are issues that undermine its commercialization. In this study, two fillers, calcined cow bone and kaolin, were introduced into a polystyrene resin matrix in varying concentrations through the hand lay‐up method. The composites were thermally cured at a temperature of 200°C for 3 h, after which they were characterized for their thermal and microstructural properties. DSC analysis revealed that the presence of kaolin improved the thermal property of the composite more than cow bone. The FTIR results revealed that the filler(s) were incorporated into the matrix via chemical reactions, as evidenced by bond breakage and formation. EDX results confirmed the incorporation of the fillers, with carbon being the most dominant element in the composites. It showed that the cow bone introduced elements such as phosphorus and calcium, while the kaolin introduced elements such as silicon and aluminum to the composite. SEM micrographs showed the presence of good interfacial adhesion between the filler(s) and the matrix. This study has shown that thermal curing is a viable solution to the shortcomings of polystyrene‐based composites and their commercialization. [ABSTRACT FROM AUTHOR]

This paper investigates the strength development of fly ash (FA)-based geopolymer paste cured by thermal and microwave radiations, together with microstructural characterisations. The results indicate that both the two methods can significantly increase the compressive strength compared to room temperature curing. Higher microwave power can promote the strength development without changing the reaction products and the final strength, owing to the accelerated formation of N-A-S-H in the reaction product under the raised temperature, characterised by the increased Si–O Q2-3 bonds and decreased Si/Al ratio. Over-time microwave radiation weakens the strength due to the formation of micro-cracks. Microwave presents higher curing efficiency than heating, producing a compressive strength of 37 MPa within 15 min. Moreover, microwave radiation can accelerate the setting progress of the fresh paste without compromising its final strength after curing. The present work can guide the preparation of FA-based geopolymers with high early strength in practice.

Understanding the curing mechanisms of adhesives presents basic knowledge of planning adhesive application and bonding processes. The demand for short manufacturing cycle times drives the development of rapid curing adhesives. Furthermore, the processing parameters influence both: the process time and the adhesive properties. This motivates upgrading the boundary conditions of common rheometric measurement methodologies to reflect application process parameters. For this purpose, it is imperative to investigate the interaction of fast-curing adhesive, rheometric method and measuring device setup. Influences on the measurement accuracy caused by highly dynamic heating processes must be minimized or compensated for in the evaluation of the results. At the same time, knowledge must be acquired on how to determine the material-specific process limits. The resulting systematics for the development of fast-curing adhesives and for the planning of adhesive manufacturing processes will enable a significant industrial spread of fast curing with all its advantages. This paper provides a first step in this process by investigating the curing behavior of a thermal rapid curing one component polyurethane adhesive at heating rates of 50 and 100 K/min. The results for the evolution of the shear modulus are compared to the results from standard rheometric methods. [ABSTRACT FROM AUTHOR]

Gelatin, a biopolymer derived from animal proteins, has been selected to stabilize three fine-grained soils by determining select index and engineering properties. Specimens for California Bearing Ratio (CBR) were tested using three different curing methods, i.e., thermally cured at 60 °C, unsoaked, and 7 days air-cured submerged specimens. The amount of gelatin added to the soil ranged from 0.5% to 2% by soil weight. The sequence of the interaction between gelatin and the clays is as follows: (A) The biopolymer solution is adsorbed and agglomerated onto the surface of the clay. (B) The presence of Al3+, Si4+, and K+ ions on the clay promotes the blending of connective linkages with negatively charged gelatin. (C) The connection reinforcements harden with the curing period and subsequent drying of the stabilized soils. (D) Drying of the gelatin–clay complex also establishes alternative bonding modes such as van der Waals interactions and ligand exchange. The biopolymer formed dry, rigid films after 72 h which were responsible for coating and reinforcing the soil particles. Thermal curing by 1% addition of gelatin yielded the maximum CBR of 91.42%, 141.1%, and 122.3% for high compressible clay, low compressible clay, and low compressible silt, respectively, and a maximum Unconfined Compressive Strength (UCS) of 3968 kN/m2 for the low compressible clay. The UCS results revealed that brittle failure was predominant for the gelatin-amended soils after 28 days of curing while shear failure was observed for the treated soils tested 2 h after sample preparation. Tests on pH revealed that the gelatin-stabilized soils displayed marginal variations after 28 days. Spectroscopic analysis revealed the various types of bonds between gelatin and the clays. A reduction in mass of 9% was observed for the alternate wetting and drying of the high compressible clay after a period of 12 cycles. The adsorption of the clay–gelatin complex was indicated by variation in average particle diameter and specific surface. Savings in 450 m3 and 93.75 m3 of coarse aggregates and dense bituminous macadam, respectively, were observed for a 1 km pavement for the stabilized low compressible clay. [ABSTRACT FROM AUTHOR]

The significant development of industry and the growing demand for renewable fuels lead to the accumulation of massive amounts of glycerol as a by-product. Scientists have been trying to use this product as a raw material for several years. One of its uses is in the acquirement of 1,3-propanediol (PDO). This work presents studies on the synthesis of two new urethane acrylate resins obtained from 1,3-propanediol and urethane acrylate oligomers containing isocyanate groups in each molecule. The method for obtaining the resins was presented, considering various conditions of synthesis, i.e., the structure of the carbon chain of the oligomer used, the molar ratio of the reactants, or the use of solvents. The reactions were monitored in real time by FTIR until the disappearance of the NCO groups. Then, polymer films were prepared from the obtained products and cured using UV radiation or thermally. The obtained coatings were tested in terms of the photopolymerization kinetics and properties of the cured coatings. Resultantly, the obtained bio-sourced coatings were observed to be characterized by good functional properties and a short curing duration, both with the use of UV radiation-based or thermal curing. These types of resins obtained using a bioproduct can be employed as eco-friendly film-forming products in the coating industry for many applications. In particular, due to their potential for dual curing methods (UV or thermal), these resins can be used on three-dimensional surfaces, i.e., those in which there is a possibility of the insufficient availability of UV radiation. [ABSTRACT FROM AUTHOR]

In this study, a simple method for preparing direct-writable and thermally one-step curable epoxy composite inks was proposed. Specifically, colloidal inks containing a mixture of ordinary epoxy resin and anhydride-type hardener with the suspended alumina microplates, as exemplary fillers, are "stained" with small amounts of water. This increases the elasticity of the ink via the interparticle capillary attraction and promotes curing of the epoxy matrix in low-temperature ranges, causing the three-dimensional (3D) printed ink to avoid structural disruption during one-step thermal curing without the tedious pre-curing step. The proposed mechanisms for the shape retention of thermally cured water-stained inks were discussed with thorough analyses using shear rheometry, DSC, FTIR, and SEM. Results of the computer-vision numerical analysis of the SEM images reveal that the particles in water-stained inks are oriented more in the vertical direction than those in water-free samples, corroborating the proposed mechanisms. The suggested concept is extremely simple and does not require any additional cost to the one required for the preparation of the common epoxy–filler composites, which is thus expected to be well-exploited in various applications where 3D printing of epoxy-based formulations is necessary. [ABSTRACT FROM AUTHOR]

It is apparent that well-designed functionally graded materials (FGMs) exhibit smooth transition in properties. In this paper, polymer based functionally graded composite materials (FGCMs) were developed in combination with copper (Cu) particles and epoxy. A novel stepped layer configuration through a curing-phase approach at each layer in three different curing conditions (C1, C2, C3) have been processed. A significant enhancement in mechanical strength and erosion resistance was observed at higher curing temperatures (60°C) for sample C3. The results indicated tensile and compressive strengths of C3 enhanced by 40.20%, 17.48% and 20.18%, 9.74% compared to C1 and C2, respectively. Furthermore, when the FGM is loaded from top to bottom (T-B), there is an enhancement in flexural strength of C3 by 7.88% when compared to bottom to top (B-T) loading. In addition, the erosion wear of C3 was found to be lowest of all the samples. [ABSTRACT FROM AUTHOR]

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel, nonreversible surface relief (SR) system was developed using polymerizable low‐molecular‐weight compounds containing two or three [(E)‐3‐[4‐(6‐methyl‐2,4‐dihydro‐1,3‐benzoxazin‐3‐yl)phenyl]prop‐2‐enoyl]oxy units in which photoreactive cinnamate moieties and thermally curable benzoxazine moieties are included. The SR structure formation was conducted using thin films (thickness: 1.5 μm) on silicon wafers through a two‐step procedure including micropatterned ultraviolet irradiation at 23°C and then heating to induce the SR pattern formation. All of the four compounds synthesized in this study showed submicron‐height SR structure on their films. After being thermally treated at 200°C for 1 h, the thin films became insoluble, which ensured the formation of crosslinked network structures. The obtained nonreversible SR system is expected to be a candidate for microfluidic channel materials for cooling semiconductor chips as well as an alternative option for photolithography. [ABSTRACT FROM AUTHOR]

UV and thermal-curing hybrid epoxy adhesives are generally developed with a combination of epoxy acrylates and thermal-curing epoxy resin. This study modified bisphenol-A type epoxy resin (ER) with acrylated epoxidized industrial crop soybean oil (AESO) to obtain a dual-curable epoxy system. Hydroxylated multi-walled carbon nanotube (MWCNT OH) and montmorillonite-type nanoclay (NC) first was used as nano reinforcement in this system. Both thermal and UV-curing were applied to composites. Tensile and hardness tests, thermogravimetric analysis (TGA), and four-point probe electrical conductivity measurements were used for the nanocomposite characterization. Although (UV+thermal) curing increased the thermal strength of the nanocomposites, it caused a decrease in their electrical conductivity and moisture absorption. The highest tensile strength values were obtained as 107 MPa and 97 MPa for thermally cured 1.5 wt% MWCNT OH and 2 wt% NC composites, respectively. The effect of the AESO ratio on UV curing of nanocomposites was investigated and 10 % was found to be the most suitable. MWCNT OH composites also exhibited the highest electrical conductivity with a percolation threshold of 1.5 wt%. The effect of hydrothermal aging on thermal and electrical conductivity properties showed that only T 5 and T 10 values of thermally or (UV+thermally) cured MWCNT OH and NC composites decreased, T 50 values did not change significantly. [Display omitted] • Epoxy resin was modified with acrylated epoxidized industrial crop soybean oil. • The properties of MWCNT composites were found higher than nanoclay composites. • (UV+thermal) curing increased the thermal stability of the nanocomposites. • Hydrothermal aging caused a decrease in thermal and conductivity properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Thermal-curing phosphorus-containing flame retardant HPG coating was prepared. • HPG coating endowed RPUF excellent flame retardancy and fire hazardous safety. • The crosslinked HPG coating provided RPUF enhanced compressive property. • HPG coated on RPUF had good heat insulation and water resistance. • The flame–retardant HPG/RPUF is promising as heat–insulation material. A phosphorous-containing HEMAP–co–GMA (HPG) prepolymer was successfully prepared by the ring-opening reaction of glycidyl methacrylate (GMA) and 2–hydroxyethyl methacrylate phosphate (HEMAP) as monomers, and flame retardant HEMAP–GMA copolymer (HPG) coating on the surface of rigid polyurethane foam (RPUF) was further fabricated by free-radical thermal-curing. The HPG coating endowed RPUF excellent flame retardancy and fire hazardous safety. The HPG coated on RPUF (HPG/RPUF) reached UL94 V–0 rating, and the limited oxygen index value of the HPG-2/RPUF improved from 19.0 % of RPUF to 27.8 %. The cone calorimetric test results showed that the total heat release and mean peak heat release rate values of the HPG-2/RPUF reduced by 79.6 % and 54.6 % compared to those of RPUF, respectively. The flame–retardant mechanism of HPG/RPUG was speculated the synergistic flame retardant effect between the barrier of the dense char layer and the inhibition of phosphorus–containing free–radicals. The three–dimensional crosslinked HPG coating not only provided HPG/RPUF excellent water resistance, but also enhanced compressive properties and heat–insulation. The highly efficient flame–retardant HPG coating has great potential in fire protection of the heat insulation foams. [ABSTRACT FROM AUTHOR]

Polyimides (PI) are a class of dielectric polymer used in a wide range of electronics and electrical engineering applications from low-voltage microelectronics to high voltage isolation. They are well appreciated because of their excellent thermal, electrical, and mechanical properties, each of which need to be optimized uniquely depending on the end application. For example, for high-voltage applications, the final polymer breakdown field and dielectric properties must be optimized, both of which are dependent on the curing process and the final physico-chemical properties of PI. The majority of studies to date have focused on a limited set of properties of the polymer and have analyzed the effect of curing from a physicochemical-, mechanical- or electrical-centric viewpoint. This paper seeks to overcome this, unifying all of these characterizations in the same study to accurately describe the universal effect of the cure temperature on the properties of PI and at an industrial processing scale. This paper reports the widest-ranging study of its kind on the effect that cure temperature has on the physico-chemical, mechanical, thermal and electrical properties of polyimide, specifically poly (pyromellitic dianhydride-co-4, 4′-oxydianiline) (PMDA/ODA). The optimization of the cure temperature is accurately studied not only regarding the degree of imidization (DOI), but also considering the entire physical properties. Particularly, the analysis elucidates the key role of the charge–transfer complex (CTC) on these properties. The results show that while the thermal and mechanical properties improve with both DOI and CTC formation, the electrical properties, particularly at high field conditions, show an antagonistic behavior enhancing with increasing DOI while degrading at higher temperatures as the CTC formation increases. The electrical characterization at low field presents an enhancement of the final PI properties likely due to the DOI. On the contrary, at high electric field, the conductivity results show an improvement at an intermediate temperature emphasizing an ideal compromise between a high DOI and PI chain packing when the thermal imidization process is performed over this equilibrium. This balance enables maximum performance to be obtained for the PI film with optimized electrical properties and, overall, optimal thermal and mechanical properties are achieved. [ABSTRACT FROM AUTHOR]

The aim of this research is to evaluate the mechanical and erosion characteristics of stepped polymeric functionally graded materials (PFGMs) reinforced with aluminum particles. By varying the filler content, gradation is achieved along the sample's thickness direction. Three distinct methodologies were adopted in the fabrication of PFGMs; no curing time between the layers (M1), providing curing time between the layers at room temperature (M2) and thermal curing between the layers at 60°C (M3). The results showed that tensile strength and compressive strength of sample M3 increased by 30.3%, 20.8% and 10.3%, 5% as compared to M1 and M2 respectively. The flexural strength of M3 was enhanced by 9% when load direction was from top to bottom (T‐B) than from bottom to top (B‐T). Moreover, the erosion resistance of M3 was higher among all the test samples. [ABSTRACT FROM AUTHOR]

Reversible addition–fragmentation chain transfer (RAFT) polymerization of 2‐(tert‐butoxycarbonyloxy)ethyl methacrylate (BHEMA) is carried out using 4‐cyano‐4‐((dodecylsulfanylthiocarbonyl)sulfanyl)pentanoic acid as the RAFT agent. The polymers with a controlled molecular weight and polydispersity are produced when a large amount of the RAFT agent is used. The RAFT polymerization of isobutyl methacrylate is also carried out using poly(2‐(tert‐butoxycarbonyloxy)ethyl methacrylate) (PBHEMA) as the macro‐RAFT agent in order to synthesize diblock copolymers with a narrow molecular weight distribution. It is revealed that the control of the polymerization of BHEMA is achieved under limited polymerization conditions. Then, the acid‐catalyzed deprotection of tert‐butoxycarbonyloxy groups of PBHEMA is performed in the presence of trifluoroacetic acid at room temperature to obtain polymers with a hydroxy group in the side chain. The hydroxy‐containing polymers are further reacted with 2‐isocyanatoethyl acrylate and methacrylate to synthesize precursor polymers used for a thermally curing system. [ABSTRACT FROM AUTHOR]

The demand and consumption of conventional concrete materials is increasing day by day, which in turn leads to the extinction of natural resources. Certain researchers tend to draw a circle to solve this global problem by finding alternative materials satisfying all aspects, mainly efficiency, eco-friendly and economical. The present research work aimed to study the combined use of coal bottom ash (CBA) and waste concrete powder (WCP) in silica fume based reactive powder concrete (SF-RPC) subjected to thermal curing. The replacement of cement by silica fume was limited to 20% and the fine aggregate quartz sand replaced by CBA and WCP varied from 5% to 25% each. The material composition of SF-RPC involves the exclusion of coarse aggregates and the inclusion of finer materials with micro-steel fibers. The steel fibers played a significant role in order to obtain a ductile and stable product of SF-RPC. The experimental investigation on SF-RPC comprised of the determination of fresh concrete properties such as slump flow and the compaction factor, as well as mechanical properties like compressive strength, flexural strength and split-tensile strength. The study was also extended to investigate durability properties such as water absorption, sorptivity and resistance to acid attack. The results showed that silica fume proves to be a feasible alternative to partially replace cement and also that optimum incorporation of pre-treated and processed CBA and WCP attains better mechanical and durability performance without compromising the necessary qualities. [ABSTRACT FROM AUTHOR]

Limitations in existing anion exchange membranes deter their use in the efficient treatment of industrial wastewater effluent. This work presents an approach to fabricating novel anion-conducting membranes using epoxy resin monomers like hydrophobic or hydrophilic diglycidyl ether and quaternized polyethyleneimine (PEI). Manipulating the diglycidyl ether nature, the quantitative composition of the copolymer and the conditions of quaternization allows control of the physicochemical properties of the membranes, including water uptake (20.0-330%), ion exchange capacity (1.5-3.7 mmol/g), ionic conductivity (0.2-17 mS/cm in the Cl form at 20 °C), potentiostatic transport numbers (75-97%), as well as mechanical properties. A relationship was established between copolymer structure and conductivity/selectivity trade-off. The higher the quaternized polyethyleneimine, diluent fraction, and hydrophilicity of diglycidyl ether, the higher the conductivity and the lower the permselectivity. Hydrophobic diglycidyl ether gives a much better conductivity/selectivity ratio since it provides a lower degree of hydration than hydrophilic diglycidyl ether. Different mesh and non-woven reinforcing materials were also examined. The developed membranes demonstrate good stability in both neutral and acidic environments, and their benchmark characteristics in laboratory electrodialysis cells and batch-mode dialysis experiments are similar to or superior to, commercial membranes such as Neosepta© AMX, FujiFilm© Type1, and Fumasep FAD-PET.

Superhydrophobic coatings promise various practical applications. A one-step, ingenious yet economical thermal curing method is devised to render the carbon nanomaterials superhydrophobic. This study aims to compare the degree of superhydrophobicity of the carbon/polydimethylsiloxane (PDMS) synthesized from the 2D graphene nanoplatelets (GNPs), 1D multiwalled carbon nanotubes (MWCNTs), and 0D carbon black (CB) nanomaterials. The superhydrophobic GNPs/PDMS, MWCNTs/PDMS and CB/PDMS are synthesized when thermally functionalized with the siloxane groups. The Fourier transform infrared spectroscopy data signifies the successful functionalization of the carbon nanostructures by siloxane chains and the Raman spectroscopy analyses indicate that GNPs/PDMS manifests the highest degree of structural defects due to functionalization. The degree of superhydrophobicity induced on the carbon/PDMS coatings correlates with the dimensions of the carbon nanomaterials (0D, 1D and 2D), which is intimately associated with the effective surface areas of the nanomaterials susceptible of chemical functionalization. The promising applications of the superhydrophobic coatings are demonstrated. This study proposes a novel wettability tuning method and provides insightful analyses and characterization of the superhydrophobicity of the thermally functionalized carbon nanomaterials with different dimensions of varied nano-geometries. [ABSTRACT FROM AUTHOR]

An experimental program was employed to evaluate the effects of curing time and temperature on the shear behavior of a sand-bentonite mixture. The specimens were treated at temperatures of 40°C, 60°C, and 80°C on Days 1, 3, and 5 under 100 kPa, 500 kPa, and 1000 kPa confinements. The results of the consolidated undrained triaxial shear tests indicated that an increase in the temperature from 40° C to 80° C on Days 1, 3, and 5 of curing intensified the shear strength by 25%, 24%, and 23%, respectively. In addition, an increase in the curing time from 1 to 3 and from 1 to 5 days at 80° C increased the shear strength of samples up to 12% and 24%, respectively. The failure of pre-cured samples was observed in lower strains as a result of greater induced brittleness. Moreover, the secant modulus and size of yield loci as well as slope of the critical state line increased by pre-curing. Application of thermal cycles resulted in increasing the shear strength and experiencing a negative pore water pressure that exhibited a transition towards the quasistructured behavior. The results of Scanning Electron Microscopy (SEM) studies confirmed an increase in the void ratio during thermal curing. [ABSTRACT FROM AUTHOR]

In this study, a simple method for preparing direct-writable and thermally one-step curable epoxy composite inks was proposed. Specifically, colloidal inks containing a mixture of ordinary epoxy resin and anhydride-type hardener with the suspended alumina microplates, as exemplary fillers, are “stained” with small amounts of water. This increases the elasticity of the ink via the interparticle capillary attraction and promotes curing of the epoxy matrix in low-temperature ranges, causing the three-dimensional (3D) printed ink to avoid structural disruption during one-step thermal curing without the tedious pre-curing step. The proposed mechanisms for the shape retention of thermally cured water-stained inks were discussed with thorough analyses using shear rheometry, DSC, FTIR, and SEM. Results of the computer-vision numerical analysis of the SEM images reveal that the particles in water-stained inks are oriented more in the vertical direction than those in water-free samples, corroborating the proposed mechanisms. The suggested concept is extremely simple and does not require any additional cost to the one required for the preparation of the common epoxy–filler composites, which is thus expected to be well-exploited in various applications where 3D printing of epoxy-based formulations is necessary.

We evaluate the behavior of a bolted joint prepared from electron beam (EB)‐cured carbon/epoxy nanocomposites under accelerated weathering environment at varying bolt tightening torques. For strength improvement, different weight percentages (wt%) of multiwalled carbon nanotubes (MWCNTs) in the range 0.1–0.5 wt% were incorporated into the composite laminates; 0.3 wt% of MWCNT had the maximum tensile strength. The properties of EB‐cured composites were compared with those of thermally cured ones. For accelerated weathering, cyclic exposure of ultraviolet (UV) radiation as well as condensation at elevated temperatures was conducted for 1000 h on the nanocomposite specimens. The chemical, physical, thermal, and mechanical properties of the nanocomposites were studied under accelerated aging conditions. To determine the failure loads in the bolted joints, specimens were prepared as per ASTM D5961. It was found that after 1000 h of aging, there was only 5% reduction in the ultimate failure load for joints prepared with the addition of MWCNTs. It was also found that the bolt torque had a positive effect on the performance of the joints. The experimental results were validated with progressive damage analysis using the characteristic curve method along with the Hashin damage criteria. [ABSTRACT FROM AUTHOR]

A high‐performance compound epoxy resin system suitable for wet filament winding was designed. The glass transition temperature reached 181.3°C, and the tensile strength, tensile modulus, and elongation of the resin casting body were 90.82 MPa, 3312.72 MPa, and 4.17%, respectively. In order to explore the mechanism of microwave curing, the microwave curing kinetics of the composites was studied. Based on differential scanning calorimetry, the curing degree and curing reaction rate of thermal and microwave curing composites were compared. The results showed that the curing degree and curing reaction rate of microwave curing composites were higher than that of thermal curing in the early and middle stages of curing reaction. The heat transfer mechanism model was proposed. The heat transfer of carbon fiber after absorbing wave is the reason for the above‐mentioned phenomenon. In the later stage of curing reaction, the steric hindrance effect is greater than that of heat transfer mechanism on curing degree and curing rate, so there is little difference between the two curing methods. The kinetic parameters of thermal and microwave curing were calculated by the Malek method, and the activation energies were 70.40 kJ/mol and 61.18 kJ/mol, respectively. The correlation coefficient R2 between the curing degree calculated by kinetic equation of microwave curing and measured by experiment was 0.951, indicating that the kinetic equation was in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The purpose of this experimental work is to develop a suitable approach for an alkali-activated binder material to replace cement CEM-II/42.5 by 80% of natural pozzolan. The chemical activity of silica and alumina found in Algeria's natural pozzolan is improved using heat treatment and chemical curing, together with several alkali activators, including a 6-mole NaOH and a 6-mole KOH along with CaCl2, Na2SO4 and Na2SiO3. The chemical and morphological processes are monitored using X-ray diffraction, TGA and DTA, as well as particle size distribution analyses. Laboratory tests show that thermal pretreatment positively affects the compressive strength; moreover, the use of 6% Na2SiO3 and 6% Na2SO4 results in increased short-term and long-term compressive strength, respectively. Optimal compressive strength values are reached under chemical activation and thermal pretreatment processes. These combined processes also affect Young's modulus values and the relative deformations caused by ultimate stresses. This experimental work highlights the potential of natural pozzolan in producing an economical and environmentally-friendly sustainable material that can be substituted for Portland cements and used in multiple engineering applications. [ABSTRACT FROM AUTHOR]

In the present work, the hygrothermal aging effect was studied on the performance of bolted joints prepared from electron beam (EB) cured carbon/epoxy nanocomposites under varying bolt torques. The multiwalled carbon nanotubes (MWCNTs) at different wt.% varying from 0 to 0.5 were added into the composite laminates with 0.3 wt.% giving the maximum tensile strength. The comparison of mechanical properties was done for thermally cured, EB cured (without post curing) and EB cured (post curing) composites. For hygrothermal aging of neat and 0.3 wt.% MWCNT configurations, water absorption studies were conducted at three different water temperatures i.e., 25 °C, 45 °C, and 65 °C for 30 days, as per ASTM D5229. The mechanical strength retention of aged composite specimens were analysed. Using ASTM D5961, the bolted joint specimens were prepared to investigate the bearing response and ultimate failure loads in the composite bolted joints. The damage occurred due to hygrothermal conditions has been interpreted in the light of their morphological structures. [ABSTRACT FROM AUTHOR]

Epoxy polymer samples cured by thermal and microwave methods under different temperature-time conditions are studied. The physical and mechanical parameters of the epoxy polymer samples, as well as their microstructure and fractographic fracture patterns, are studied. A tensile test method is used is used to determine the dependence of their strength parameters on the curing regime. Optimal regimes are identified for both curing methods, which makes it possible to obtain samples with maximum strength. Electron microscopy is used for comparative fractographic analysis of the fracture surfaces of samples with similar strength characteristics with thermal and microwave curing. It is found that microwave curing yields an increased globule size and more nanopores, as well as more pronounced local plastic deformation during fracture, and a larger spread in the ratio of the propagation velocities of main and secondary cracks. The dependence of the optical density of the test samples on the thermal and microwave curing regimes is established for wavelengths of 360–2500 nm. [ABSTRACT FROM AUTHOR]

Polyimides (PI) are a class of dielectric polymer used in a wide range of electronics and electrical engineering applications from low-voltage microelectronics to high voltage isolation. They are well appreciated because of their excellent thermal, electrical, and mechanical properties, each of which need to be optimized uniquely depending on the end application. For example, for high-voltage applications, the final polymer breakdown field and dielectric properties must be optimized, both of which are dependent on the curing process and the final physico-chemical properties of PI. The majority of studies to date have focused on a limited set of properties of the polymer and have analyzed the effect of curing from a physicochemical-, mechanical- or electrical-centric viewpoint. This paper seeks to overcome this, unifying all of these characterizations in the same study to accurately describe the universal effect of the cure temperature on the properties of PI and at an industrial processing scale. This paper reports the widest-ranging study of its kind on the effect that cure temperature has on the physico-chemical, mechanical, thermal and electrical properties of polyimide, specifically poly (pyromellitic dianhydride-co-4, 4′-oxydianiline) (PMDA/ODA). The optimization of the cure temperature is accurately studied not only regarding the degree of imidization (DOI), but also considering the entire physical properties. Particularly, the analysis elucidates the key role of the charge–transfer complex (CTC) on these properties. The results show that while the thermal and mechanical properties improve with both DOI and CTC formation, the electrical properties, particularly at high field conditions, show an antagonistic behavior enhancing with increasing DOI while degrading at higher temperatures as the CTC formation increases. The electrical characterization at low field presents an enhancement of the final PI properties likely due to the DOI. On the contrary, at high electric field, the conductivity results show an improvement at an intermediate temperature emphasizing an ideal compromise between a high DOI and PI chain packing when the thermal imidization process is performed over this equilibrium. This balance enables maximum performance to be obtained for the PI film with optimized electrical properties and, overall, optimal thermal and mechanical properties are achieved.

Superwettable materials are destined for a wide range of multifunctional applications. An ingenious, cost-effective yet simple method is proposed to control the superwettability of graphene through a thermal curing process at 300 °C under atmospheric pressure. By functionalizing graphene nanoplatelets (GNPs) with oxygenated groups, superhydrophilic surface with a water/air contact angle of 0° manifesting the ultrafast water permeation property is synthesized. Oppositely, superhydrophobic surface with antiadhesive property to water is obtained by functionalizing GNPs with siloxane groups under the same conditions. The superhydrophobicity is justified with a static contact angle of 163° ± 2.8° with a low contact angle hysteresis of 1.53° ± 0.86°. The chemical structures of the superwettable graphene are elucidated using various spectroscopy techniques. Theoretically, by using molecular dynamics simulations, we have further examined and testified the tunable superwettability phenomena of graphene. This study provides important insights into a facile approach in synthesizing advanced materials with superwettability for multifunctional high-performance applications. Unlabelled Image • Superwettable graphene surfaces are obtained through a thermal curing process. • The superhydrophilic surface manifests ultrafast water permeation property. • The superhydrophobic surface with a contact angle of 163° is antiadhesive to water. • The chemical structures are elucidated using various spectroscopy techniques. • Molecular dynamics simulations evidence the tunable superwettability of graphene. [ABSTRACT FROM AUTHOR]

In the present study, a novel and easy approach for an oil-based binder production was realized by the modification of partial glycerides (PGs) with benzoxazine functionalized silane (Bz-Si) which was synthesized by the reaction between benzoxazine and 3-aminopropyltriethoxysilane. PG mixture obtained by the glycerolysis reaction was subjected to solvent extraction with methanol to concentrate PG. The enhanced partial glycerides (PGE) were thermally cured with Bz-Si. After that, the film sample cured by means of sol–gel reaction (CF(Bz-Si)/PGE) was examined in view of film properties. Applied tests showed that CF(Bz-Si)/PGE could be used as an oil-based binder for coating applications. [ABSTRACT FROM AUTHOR]

Soft-feel coatings for automotive interior parts are a crucial factor in consumer purchase preferences owing to the growing awareness of human sensibility ergonomics. Herein, the thermal curing of commercial-grade polyurethane (PU) coatings was optimized using advanced spectroscopic tools. Conventional FTIR spectra were collected at various curing temperatures and times, and analyzed using two-dimensional (2D) gradient maps and 2D correlation spectroscopy (2D COS); while the former demonstrates the spectral variation trend with curing time, the latter provides whole spectral sequences that inform the cure reaction mechanism. The thermal curing continued for 50 min at 60 and 70 °C, and was halted after 30 min above 80 °C. According to the 2D COS and kinetic model fitting, the cure reaction was initiated by solvent evaporation and followed nucleation and growth mechanisms. PUs cured at lower temperatures were ductile owing to incomplete reactions, whereas PUs cured above 80 °C exhibited brittle features. Consequently, the optimal curing process was determined to be at 80 °C for 30 min. The 2D FTIR analytic tools can be useful in the development of high-quality soft-feel coatings for automotive interior parts. [Display omitted] • Thermal curing process of polyurethane coating is optimized using 2D FTIR tools. • Optimal curing conditions of PU are determined to be 80 °C and 30 min. • Solvent evaporation initiates curing at 80 °C, followed by nucleation and growth. • Curing below 70 °C for 30 min yields immature PUs due to incomplete reaction. • Mechanical and chemical resistances of 80 °C-cured PUs are sufficient for coatings. [ABSTRACT FROM AUTHOR]