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Liquid dyes are discharged usually from different industries, such as textile factories, into water bodies. They are toxic compounds that can cause significant harm to humans, animals, and aquatic life due to increased water pollution. For this reason, removing dyes from wastewater is of great importance to control their negative impact and meet the standards of water quality. In this study, activated carbons were produced from phenolic resin through a chemical activation process with NaOH at high temperatures. The sample that had highest porosity and pore volume was used to adsorb two types of azo dyes Remazol Brilliant Blue R (RBBR) and Remazol Yellow dye (RY) from an aqueous solution under different conditions, i.e., changing contact time, pH, dosage, initial concentration, and temperature. The maximum removals of RBBR and RY were recorded separately at low concentration (10 ppm), acidic condition (pH < 7), adsorbent dose of 0.3 g, temperature of aqueous solution 20°C and contact time of 120 min. The Freundlich adsorption isotherm model, with its higher correlation coefficient, provided a better fit for the equilibrium data compared with the Langmuir isotherm model. The activated carbon derived from phenolic resin, which is chemically activated with NaOH at 850°C, is a promising adsorbent for the removal of azo dyes from aqueous solutions. The optimum conditions can increase the efficiency of the adsorption process. [ABSTRACT FROM AUTHOR]

This study assesses the environmental and social impacts of a modified softwood produced using radiata pine sourced from New Zealand or Chile. The LCA found that differing forestry and transport burdens associated with each location broadly cancelled each other out, giving overall product footprints that were very similar. Boiler gas and phenol-formaldehyde resin were the biggest emitters of GHG emissions, and normalization highlighted toxicity impacts as significant, largely due to the resin input. SLCA hotspots analyses suggest that the forestry sector in Chile has more potential social risks than the equivalent sector in New Zealand. However, each sector scored poorly in different social aspects making it difficult to recommend a sector without introducing subjective judgements. Combining LCA with SLCA is still novel, but this study found it added useful insights into a broader range of impacts associated with sustainable production, especially given the similarity of the environmental LCA results taken alone. [ABSTRACT FROM AUTHOR]

In this study, the combined process of phenolic condensation-persulfate(PS) advanced oxidation was adopted to treat semi-coking wastewater. Using the phenolic condensation method as a pretreatment unit to remove phenolic substances for the preparation of phenol-formaldehyde resins, and using an aerated/PS/pyrite oxidation system as a deep treatment unit to remove chemical oxygen demand (COD) and ammonia nitrogen (NH 3 -N) from the wastewater. Analysis and characterization of phenol-formaldehyde resin, organic compounds in wastewater, and pyrite using FT-IR, TG-DTG, GC-MS, and XPS techniques. The results showed that under the conditions of adding 1.8vt % formaldehyde, pH 10.5, reaction temperature 95 ℃ and reaction time 3 h, the removal rates of volatile phenol, COD and NH 3 -N in semi-coke wastewater were 97.54 %, 41.14 % and 56.50 %, and the yield of phenolic resin was 6.62 g/L. Subsequently, treated with an aerated/PS/pyrite system, the PS concentration 0.4 mol/L, the pyrite dosage 15 g/L, the pH 3, the temperature 65 ℃, and the aeration 3 h, the removal rates of COD and NH 3 -N are 99.20 % and 86.80 %. In the phenolic condensation process, phenolic substances in semi-coke wastewater generate phenoxy anions under the influence of OH-, which undergo addition reactions with formaldehyde to produce hydroxymethyl phenol. Hydroxymethyl phenol further undergoes condensation reactions with other phenolic substances and itself to form phenolic resin, while amide compounds are generated through reactions between ammonia nitrogen and carboxylic acid substances. In the aeration/PS/pyrite system, Fe2+ released from pyrite oxidation activates PS to produce SO 4 •− and O 2 •−. The contribution of free radical oxidation and decomposition of pollutants such as phenols, amides, and NH 3 -N in wastewater is 84.60 %. Specifically, SO 4 •− oxidation contributes 61.54 %, while O 2 •− accounts for 22.21 %. Amide compounds and phenolic substances in the wastewater are oxidized, leading to ring opening and chain scission, resulting in the formation of alkane compounds. • Combined phenolic condensation-persulfate advanced oxidation for semi-coke wastewater treatment. • Phenolic condensation recovers volatile phenols and yields phenolic resin from semi-coke wastewater. • Organic pollutant oxidative degradation primarily due to indirect oxidation of SO 4 •− and O 2 •−. • Aeration and pyrite activation aid in producing SO 4 •− and O 2 •− in the persulfate oxidation system. [ABSTRACT FROM AUTHOR]

• Phenolic resin-derived hard carbon (PRHC) spheres are synthesized from 700 to 1000 °C. • Both Li ions and Na ions storage mechanisms of PRHCs are studied. • Adsorption energy of Li/Na ions on graphene with different oxygen defects iscalculated by theoretical calculations. • The optimized-PRHCs delivers 151 mAh g-1 at 1.0 A g-1 after 200 cycles for Na ion battery. Batteries or electrochemical energy storage devices are dependable substitutes for electrical energy storage systems that rely on fossil fuels and are essential in reducing greenhouse gas emissions. As a result, one of the most promising sustainable materials for energy storage is hard carbon (HC). We propose both Li and Na ions storage mechanisms of hard carbon spheres derived from phenolic resin (PRHCs). The characterization and electrochemical analyses of the PRHCs synthesized at different temperatures were performed. The PRHCs at various sintering temperatures from experimental and theoretical calculations were investigated. The investigation highlighted the role of C=O in determining the electrochemical performance of PRHCs, as well as the relationship between the ratio of micropores and mesopores and Na/Li ions' storage mechanisms. DFT calculations showed an enhancement in Na/Li adsorption with the existence of C=O in the graphene. The electrochemical performance of PR800, which was obtained after sintering at 800°C, demonstrated the highest reversible capacity of 151 mAh/g after 200 cycles at 1.0 A/g. Both capacitive-controlled and diffusion-controlled mechanisms were found to be significant in Na ion transfer, according to the electrochemical investigation. The as-synthesized hard carbon exhibited potential as anode materials for both Na and Li ion batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

Lignin is the principal residual product of the papermaking industry. Due to its ample availability and renewable advantages, it is widely utilized. We extracted poplar wood containing lignin phenols using a simple papermaking technology from pulping, lignin phenol and formaldehyde polymerization was utilized to prepare lignin-based phenolic resins. Fe species were introduced during polymerization. Fe-C catalysts were obtained via a further annealing, and the catalysts exhibit a rough spherical structure. Where the Fe/Fe 3 C/Fe 3 O 4 multicomponent nanoparticles were proved decorated on the carbon spheres. Ultraviolet photoelectron spectroscopy revealed that the introduction of Fe enhances charge redistribution, improves the electron-acceptance ability of the catalyst and promotes the adsorption of reactant molecules. Electrochemical detection of 4-nitrophenol using prepared Fe lignin based phenolic resin derived carbon. The Fe-C catalyst exhibited a robust adsorption effect on nitroaromatic hydrocarbons and may facilitate the rapid transfer of H+ to the nitro group, expediting the reduction process. According to the calibration curve, the limit of detection (LOD) is 0.0111 µM within the linear range of 1–100 µM. • Extracting lignin and cellulose from poplar through pulping, lignin and cellulose were pyrolyzed to produce carbon materials. • The electrochemical reduction effects of lignin and cellulose carbon on 4-nitrophenol and 2-nitrophenol were different. • Two newly developed sensors allowed sensitive detection of 4-nitrophenol and 2-nitrophenol. [ABSTRACT FROM AUTHOR]

The pine needles bio-oil was partially replaced with phenol-formaldehyde (PF) resin at a rate of up to 40% by weight. The wood adhesive characteristics of a newly produced bio-oil phenolformaldehyde (BOPF) resin with 10% bio-oil replacements was found to be comparable to those of pure PF resin with similar shear strength. DSC revealed that the curing temperature of 20 wt-% BOPF resin decreased from 95 to 60°C. Thermal degradation of BOPF resins was somewhat lower than that of pure PF resin, according to TGA and DTG data, and was similar in 10 and 20 wt-% BOPF resins. The presence of methylene bridges between phenols shown by FTIR analysis indicated that the wood adhesive had a good quality. According to SEM examination, the 10 and 20% BOPF resins showed a flat microstructure comparable to the pure PF resin. [ABSTRACT FROM AUTHOR]

• Bio-derived chemical treated adsorbent for non-radioactive iodine removal. • The separation efficacy of the bio-sorbent for non-radioactive iodine was 3.64 mg/g. • The bio-treated sorbent are efficient in iodine separation both in batch and column mode. Management and separation of radioactive iodine from wastewater of nuclear power plants is time-dependent and needs lot of efforts. Changes of surface chemistry due to radioactive irradiations are the major issue for developing an efficient adsorbent for separation of radionuclei from wastewater. This article presented a promising case of separation of non-radioactive iodine from aqueous solution using neem oil phenolic resin treated lignocellulosic biomass. The resin was prepared with some ingredients with known properties of radiation absorption. The data pointed that the treated biomass has the efficacy of iodine separation from aqueous solution within wide range of pH. The iodine sorption followed the Langmuir isotherm indicating a monolayer surface adsorption reaction. The maximum iodine removal efficacy of the resin treated biomass was 3.64 mg/g. The iodine adsorption was found to follow the pseudo second order reaction. The kinetic analysis also indicated that both surface adsorption and intraparticle diffusion were likely to control the rate of iodine-adsorbent. The treated adsorbent also showed iodine removal efficacy in column mode. The resin used for the treatment of lignocellulosic biomass was prepared using cashew nut shell liquid and phenol-formaldehyde that are known for their radiation adsorption and antioxidant properties. Thus, neem oil cashew nut shell liquid containing phenol formaldehyde resin treated biomass is expected to be stable under radioactive radiation. As radioactive iodine generation is a common phenomenon for nuclear power plant the bio-based chemical modified lignocellulosic adsorbent could be a promising alternative. However, more detail investigations with radioactive iodine containing real wastewater from nuclear power plant is needed for validation of our statement. [Display omitted] [ABSTRACT FROM AUTHOR]

The present work was initiated to finalize resin for the development of thermal protection system (TPS) for the external surface of a polymeric composite rocket motor case made up of Carbon roving and Epoxy resin. The temperature on the outer surface of the composite case increases due to kinetic heating caused by aerodynamic drag and vehicle velocity. These rocket motor casings are functionally required only in the ascent phase of missile trajectory till motor action time and stage separation. Due to which the experienced heat flux is relatively less, and the temperature on the external composite case is in order of 250 °C - 300 °C depending on missile configuration & trajectory, unlike extreme thermal conditions on ablative nozzle liners exposed to rocket motor exhaust. The maximum allowable temperature in the present study for the Carbon-Epoxy case is 100 °C due to degradation in mechanical properties. The thermal protection system on the external surface will function as a heat-insulating layer based on the working mechanism of ablation. The resin of the thermal protection layer has a substantial impact on the manufacturing process and curing aspects, especially compatibility with the pre-cured carbon epoxy case layer. The generation of test results for thermal stability, cure characteristics and Tg for Epoxy resin has also been included in present studies as an additional objective that provides significant inputs for process development. The test results for Epoxy resin is also used as a basis for the finalization of resin for the thermal protection layer for processing aspects apart from its basic thermal stability characteristics. The ablative thermal protection working mechanism is based on the ablation phenomenon. In the case of ablation, resin plays a vital role due to pyrolysis and other thermal characteristics. In the present experimental studies, the Phenolic resin and Silicone resin are considered as candidate resin materials for ablative thermal protection system based on available literature and in house experience. The main objective of the present studies is to evaluate thermal stability, char yield after final decomposition through DSC and TGA techniques for both resins as these are fundamental characteristics needed for the present specific application. The test results for specific grades (formulation) of phenolic and Silicone resins are generated and compared. In the present work, the experimental studies to evaluate glass transition temperature (Tg), thermal stability, and cure characteristics for Epoxy resin is also carried through DSC. The test results of specific grade Epoxy resin provides a basis to assess thermal margins for resins selected for ablative thermal protection system and inputs for process development and design requirements. The scope of the present studies is aimed to finalize the resin system for external thermal protection of composite rocket motor case based on thermal characteristics test results and other compatibility aspects with the structural layer. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute 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.)

An activated carbon membrane (ACM) doped with hexagonal boron nitride (h -BN) was fabricated by using activated carbon as the raw material and phenolic resin as the binder. The preparation process involves blending raw materials, ball milling, membrane pressing, and high-temperature carbonization. The conductive ACM was employed as an anode to constitute an electrochemical membrane reactor (EMR) for phenol removal. The effect of h -BN doping rate (0–5 wt%) on the properties of ACM was explored. Results showed that ACM1 (1 wt% h -BN) displayed a small pore size (20 nm), high porosity (41.6 %), large specific surface area (446.8 m2/g), and strong mechanical strength (15.4 MPa) compared to the pristine ACM0. The oxygen precipitation potential of ACM1 (2.11 V) was much higher than that of ACM0 (1.53 V), thus reducing oxygen generation at the anode in EMR for phenol degradation. The phenol removal rate of phenol obtained from EMR with ACM1 as the anode at 1.5 V was up to 95.6 %, which was much higher than that for ACM0 (39.3 %). Density functional theory (DFT) calculations and experimental results confirmed that h -BN-doping enhanced the adsorption active sites, and adsorption energy, leading to the high performance of EMR for phenol removal. In addition, the equilibrium adsorption capacity of ACM1 (10.2 mg/g) was much higher than that of ACM0 (3.7 mg/g). The C atoms adjacent to pyridine N in ACM1 were identified as the adsorption and active catalytic sites by X-ray photoelectron spectroscopy (XPS) and DFT calculations. Therefore, this study sheds light on the design and fabrication of conductive carbon membranes for enhanced performance in industrial wastewater treatment. [Display omitted] • h -BN-doping ACM was fabricated by carbonizing activated carbon and phenolic resin • ACM1 displayed a small pore size, high porosity and large specific surface area. • h -BN-doping enhanced the adsorption energy and the performance for phenol removal. • EMR with ACM1 as the anode showed a high phenol removal (95.6 %) at 1.5 V. • The C atom adjacent to pyridine N was the active site for adsorption and catalysis. [ABSTRACT FROM AUTHOR]

• A microporous polymeric resin St-DVB-Al and nitro/amine modified resins were prepared. • The novel adsorption trends to phenols were revealed and systemically discussed. • The adsorption isotherms and thermodynamic studies verified the adsorption trends. • The DFT model explained the interaction forces in the adsorption processes. A hypercrosslinked resin, named St-DVB-Al, was prepared by optimizing the conditions of the Friedel–Crafts reaction. The nitro and amine groups were further introduced into the skeleton to prepare the composite functional resins St-DVB-nitro and St-DVB-amine. The adsorption capacity of the modified resins for phenolic compounds reached to 412.9 mg/g, which were 16.4–47.7% higher than the commercial resin H103 with similar physical structure. For the p-nitrophenol and p-hydroxybenzoic acid, the adsorption capacity trends were St-DVB-amine > St-DVB-Al > St-DVB-nitro, but for the hydroquinone was St-DVB-nitro > St-DVB-amine > St-DVB-Al. The reason St-DVB-nitro exhibited efficient adsorption for hydroquinone was that the electron-acceptor group enhanced the synergistic conjugation with the electron-donating compound. The introduction of the electron-donor group in St-DVB-amine enhanced the synergistic conjugation with electron-acceptor compounds as well as the hydrogen bonding and acid-base interaction, thus exhibiting highly efficient adsorption for p-nitrophenol and p-hydroxybenzoic acid. The DFT model was used to calculate the ΔE values of St-DVB-nitro, St-DVB-amine and St-DVB-Al with three adsorbates, and the results were consistent with the adsorption trends. Relationship between adsorption capacity and adsorption behavior was clarified by a quantitative perspective. [ABSTRACT FROM AUTHOR]

Although the ceramic-coated separators have been industrialized and widely used in power lithium-ion batteries to replace the polyolefin separators, the safety of batteries still cannot fully meet the demand of practical application with the rapid growth of energy density. In this work, a ceramic-coated separator further modified by phenol-formaldehyde resin has been developed, in which a three-dimension coating layer is formed both on the surface and in the pores of the pristine separator by introducing phenolformaldehyde resin through a simple soakage process. Such membranes show extremely high thermal stability up to 300°C, maintain a high mechanical strength even after a heat-treatment at 220°C for 30 min, and show a shut-down function above 138°C. With the advantages of abundant sources, low cost, environment-friendly property and simple preparation process, the phenol-formaldehyde resin modified separators are expected to replace the commercial ceramic-coated separators, greatly improve the safety performance of batteries, and realize the reassuring application of lithium-ion batteries in power batteries and large-scale energy storage devices. [ABSTRACT FROM AUTHOR]

Different amounts of glyoxal and paraformaldehyde were used to synthesize phenol-glyoxal (PG) and phenol-paraformaldehyde (PPF) resins, which were compared with conventional phenol-formaldehyde (PF) resins. Glyoxal oxidation leads to a pH value of 9.83 for PG 2.2. With the addition of polyformaldehyde, PPF 2.2 exhibited the highest viscosity at 17333.33 mPa s. The PPF 2.0 plywood has a maximum bonding strength of 1.94 MPa. The formaldehyde emission of PG 1.8 plywood is found to have a minimum value of 0.025 mg/m3, reaching the E NF limit (≤0.025 mg/m3). Acetaldehyde is found only in volatile organic compound (VOC) emissions from PG plywood and is associated with increased glyoxal. PPF plywood emitted more aromatic and total VOC (TVOC) than the other two plywood types. The measured TVOC for PPF 2.2 is 196.07 μg/m3. The results showed that the total cancer risk (TCR) values of PPF 1.8, PPF 2.0, and PG 1.8 were above the threshold of 1.00E-4, indicating a definite carcinogenic risk. Acetaldehyde in the PG plywood exceeded the safety threshold for noncarcinogenic risk. The use of paraformaldehyde in the wood-based panel production is been considered a possible means of improving the bonding strength of plywood. Glyoxal has also been shown to be a viable method for lowering the formaldehyde emissions from plywood. The VOC emissions from plywood changed significantly depending on the aldehyde used. Limiting VOCs that present high health hazards is crucial for reducing the negative impact of plywood on both indoor environments and human health. [Display omitted] • The formaldehyde emission of PG 1.8 plywood has a minimum value of 0.025 μg/m3. • Different aldehydes result in different VOC emissions from plywood. • The aromatic VOCs and TVOC in PPF plywood are higher than the other two plywood. • Acetaldehyde was only found in PG plywood, especially as glyoxal increased. • HQ acetaldehyde from PG plywood exceeds the noncarcinogenic risk level (≤1). [ABSTRACT FROM AUTHOR]

The CO 2 -based diblock copolymer, poly(ethylene oxide- b -cyclohexene carbonate) (PEO- b -PCHC), was synthesized via ring opening copolymerization (ROCOP) by using PEO as a macro-chain-transfer agent. Theses diblock copolymers were comprehensive characterized by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to gain insights into their chemical structures and thermal properties. The microphase separation was induced after blending with phenolic resin through medicated by competitive hydrogen bonding interaction between phenolic hydroxyl (OH) group with ether unit of PEO and C O unit of PCHC based on FTIR analyses. Small angle X-ray scattering (SAXS) analyses also provided the self-assembled structures of specific phenolic/PEO- b -PCHC blends following thermal polymerization at 180 °C because of the reaction-induced microphase separation mechanism. Upon removal of PEO- b -PCHC diblock copolymer templates at 350 °C, mesoporous phenolic resins including cylindrical, spherical and worm-like structures were obtained based on SAXS, transmission electron microscope (TEM) and nitrogen adsorption/desorption analyses. Furthermore, the mesoporous carbons were further obtained from mesoporous phenolic resin thermal calcined at 700 °C under N 2 atmosphere. These carbonized mesoporous materials exhibited impressive characteristics such as high surface areas and they demonstrated effective CO 2 capture capabilities (4.5 mmol g−1 at 273 K). The captured CO 2 could subsequently be employed in ROCOP again for synthesizing CO 2 -based copolymers, aligning with the principles of a circular economy. [Display omitted] • Poly(ethylene oxide- b -cyclohexene carbonate) copolymers are synthesized through ring opening copolymerization. • The K A difference between two segments can induce microphase separation after blending with phenolic. • The resulting mesoporous carbon possesses S BET of 509 m2 g−1 and displayed higher CO 2 capture ability (4.5 mmol g−1). [ABSTRACT FROM AUTHOR]

Abstract Over the past five years, the mobilization of fiber wood assortments for promoting material use, and the integration of supply and conversion chains between biorefineries and the wood panel industry have been intensively investigated. In this regard, the production of fibers and by-products from industrial wood and the substitution of phenolic resin systems with natural polymers such as lignin offer a promising alternative for increasing the bio-based content in composite materials. A direct use of the natural lignin without intermediate downstream processing could support the implementation of energy efficient and short processing routes. But it also could open new challenges such as to identify the extent to which substitution of phenolic resins are technically feasible without compromising the required mechanic performances of the obtained products. For this reason it is needed to identify the material compositions in laminate production, which exhibit good mechanic performance values and in the same time contribute to the reduction of environmental impacts. Considering these constraints in material design, practical results from material testing of different composite materials were used to conduct a comparative Life Cycle Assessment (LCA). The environmentally most preferable compositions of beech fiber laminates are identified for the selected product compositions. Furthermore a LCA scenario analysis is applied to compare the environmental preferability of the use of industrial wood assortments in fiber provisioning against the use of industrial wood residues within coupled production schemes of the wood-based bioeconomy. The results show that in nine out of eleven impact categories reduction potentials of up to 39% are achieveable and that the use of residue streams shows a rather limited benefit in realizing further reduction potentials. [ABSTRACT FROM AUTHOR]

Abstract Bio-oil was added as a substitute of phenol for phenol-formaldehyde (PF) resin to reduce the cost and formaldehyde emission (FE) in radiant floor heating system. The effects of substitute rate of bio-oil to phenol, temperature and heating time of radiant floor heating system on the FE of plywood with bio-oil phenol-formaldehyde (BPF) resin were examined using desiccator method. The variations on chemical structure of cured BPF resin were analyzed by the Fourier transform infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance (NMR) to understand the FE behavior of plywood. Results showed that the FE of plywood was increased at prolonged heating time and the temperature significantly affected FE of plywood; the initial FE value at 50 °C was 20–30 times as higher as that at 20 °C. Elevated temperature increased the final equilibrium FE value and shortened the time to reach the balance. However, adding bio-oil reduced the initial and final equilibrium FE values, decreasing by 12–49% and 25–51%, respectively. Analytical results revealed that the initial FE was mainly from the residual formaldehyde from the manufacturing of plywood and the subsequent FE released owing to the breakage of C–O–C and CH 2 bonds in resin. Highlights • The formaldehyde emission behavior of plywood with bio-oil phenol-formaldehyde resin was examined. • Adding bio-oil to PF resin could weaken the enhancement effect of temperature on formaldehyde emission. • The initial and final equilibrium values of formaldehyde emission were decreased after adding bio-oil. • The formaldehyde emission behavior was explained by the variations on the chemical structure of cured adhesive. [ABSTRACT FROM AUTHOR]

Purpose - The literature reveals there is a limited knowledge regarding the extraction of long natural fibers, in particular those extracted from leaves. This investigation aims to present the extraction process and the characterization of long natural cellulose fibers from doum palm leaves (Hyphaene thebaica L.), with properties suitable for polymeric composite materials and textile applications. Design/methodology/approach - The resulting H. thebaica L. fibers were identified using Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The physical properties of the extracted fibers were measured to estimate the reliability of extraction conditions. Mechanical properties were evaluated to determine ultimate strength, Young'smodulus and strain-at-failure of the fibers of the doum leaves. Findings - The following properties of the doum palm are listed in this paper: physical properties of doum palm fibers (H. thebaica L.), TGA, XRD of doum palm fibers, tensile properties of doum palm fibers and surface morphology of doumpalm fibers. Research limitations/implications - Like synthetic fibers, the inclusion of short or long natural fibers into the polymer matrix can increase tensile, flexural and compressive strengths of these matrixes. Compared to the short-length natural fibers, longer-length fibers provide better reinforcements and therefore accord higher performances to the composites. Long fibers can also provide exceptional opportunities to develop a new class of advanced lightweight composites and have the potential to rival glass fiber in the manufacture of composite materials, using matrix materials, such as polypropylene, epoxy and phenolic resins. Originality/value - The following values are presented in this paper: density of doum palm fibers = 1.14-1.40 g/cm², linear density (Tex) = 33.10 611.5, equivalent diameter (mm) = 178.72 6 41.7, diameter (mm) = 137.02-220.42, tensile strength (MPa) = 124.84-448.10, Young's modulus (GPa) = 8.06-19.59, strain-atfailure (%) = 0.81-2.86. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of curcuminoids on the dentin endogenous protease activity. Demineralized dentin were pretreated with 50 or 100 µM of three different curcuminoids for 60 s and incubated up to 3 months. Untreated beams served as controls. Dry dentin mass was measured after incubation. Aliquots were analyzed for the quantity of ICTP and CTX releases for MMP and cathepsin-K mediated degradation, respectively. The effect of curcuminoids on matrix-bound MMP and soluble rhMMP-9 were measured using an activity assay. Data were subjected to repeated-measures-ANOVA (α=0.05). Gelatinolytic activity was analyzed using zymography. ICTP and CTX release and dry mass loss of curcuminoid-treated groups were significantly lower than the control. Inhibition of rhMMP-9 varied from 29-49% among curcumonoid-treated groups, whereas no inhibition was observed at untreated control (p>0.05). Results were confirmed by zymography. The study showed that the pretreatment of dentin matrices by curcuminoids decreases endogenous protease activity-mediated degradation in dentin. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute 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.)

Nitrogen (N)-doped microporous hollow carbon spheres were prepared by facilely nanocasting spherical SiO 2 with N-containing melamine phenolic resin through a simple in-situ polymerization process. Through regulating the dosage of melamine, N content in microporous hollow carbons could be easily tuned to an unprecedented level of 49.2 wt%. Additionally, in order to address the common problem of relatively poor structural porosity of N-doped carbons, especially after incorporating vast N into carbon frameworks in reported literature, a comprehensive strategy including optimizing carbonization temperature and performing further activation by CO 2 and KOH were explored, and their effects on material textural properties and CO 2 capacity were systematically studied. Although this strategy did not completely avoid the N loss during activation of carbon materials, it sharply promoted the textural properties of carbon materials at the expenses of partial N and efficiently produced a series of highly microporous carbon materials, still with abundant N species (11.5 ∼ 29.9 wt%) and large structural porosity (330 ∼ 1263 m2/g). More importantly, these N-doped microporous hollow carbons, when used for CO 2 capture, showed superior CO 2 capacities of 3.00 mmol/g (25 °C and 1 bar) and 1.05 mmol/g (40 °C and 0.1 bar), exceptionally robust cyclic stability, and low regeneration energy of 2.75 GJ/ton CO 2 , which is much lower than aqueous amine-based absorbents and comparable to amine-supported adsorbents. Thus, these outstanding adsorption performances make the N-doped microporous hollow carbon spheres prepared in this study more promising for energy-effective CO 2 capture from dilute gas streams. [Display omitted] • N-doped microporous hollow carbon nanospheres were prepared by an in-situ hard-casting method. • Optimization of melamine quantity, carbonization temperature, and CO 2 or KOH activation were carried out. • Adsorbent with CO 2 capacity of 1.05 mmol/g (40 °C and 10% CO 2), and regeneration energy of 2.75 GJ/ton CO 2 were obtained. • The N-doped carbon exhibited extremely robust cyclic stability in 50 runs. [ABSTRACT FROM AUTHOR]

Pore distribution characteristic is one of the most crucial factors for porous adsorption materials, and the variety of volatile organic compounds (VOCs) approaches about how to simply and accurately tailor practical porous carbons for VOCs adsorption has gradually attracted attention. Here, precursors with different lignocellulose mass ratios have been used to produce porous carbon for model experiments to investigate the influence of the precursor lignocellulose contents on the pore structure and distribution characteristics of porous carbon, and the applicability of these mechanisms to real biomass materials has been further verified through bacteria-targeted bagasse decomposition: the microvolumes of ultra-micropores have decreased with decrease in cellulose contents, while mesopores have followed the reverse trend. The dynamic toluene adsorption/desorption performances of the obtained samples have been tested. The BACs-36 exhibits high toluene adsorption performance in low concentration with 635 mg/g while the BACs-48 shows excellent reusability in 10 times cycles. Based on this the balance between the adsorptive and regenerative capacities has been observed which indicates that carbon materials with abundant micropores and narrow mesopores have much better adsorption performance than porous carbon with a hierarchical pore structure, while the latter show better regeneration abilities than the former, which resulting in less desorption as a counter-acting force at the pore wall. Furthermore, the porous carbon has been shaped by one-step co-pyrolysis method using phenolic resin, which can not only maintain the hardness but also can avoid pore plugging phenomenon. [Display omitted] • Pore structure of porous carbon was determined by basic components of biomass. • Bacteria degradation could effectively control the cellulose contents of biomass. • Samples exhibited excellent toluene adsorption performance and renewability. • A game balance between adsorptivity and renewability of adsorbents were observed. • High performance shaped porous carbon had been prepared. [ABSTRACT FROM AUTHOR]

A sustainable novolac-type resin – phenol–hydroxymethylfurfural (PHMF) resin was prepared by reacting phenol with HMF, in-situ derived from glucose, at 120 °C by acid catalysis. Bisphenol A type epoxy resin, i.e. bisphenol A diglycidyl ether (DGEBA), was used as a formaldehyde-free curing agent by substituting conventional formaldehyde-based hexamethylene tetraamine (HMTA) to crosslink the PHMF resin. Curing mechanism was probed and the curing proceeded likely with the ring opening reaction between the DGEBA and reactive hydroxyl groups. DGEBA not only made this system truly formaldehyde-free but also helped form a void-free matrix which is an important merit for composites. The kinetic parameters of the curing reaction were evaluated with model-free and model-fitting methods using exothermal peak data from the curing process. The thermo-mechanical characterization of the cured resin and fiber reinforced bio-composites showed good heat resistance and mechanical performance, suggesting its potential for producing void- and formaldehyde-free composite materials. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute 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.)

Aromatic hydrocarbons such as 2,4-dichlorophenoxyacetic acid (2,4-D), a common herbicide, is often found in groundwater in areas with intensive agricultural activities. Even in minute concentration, they are known to affect human health. An attempt has been made to capture 2,4-D from aqueous medium using neemoil-phenolic resin treated lignocellulosic jute. Treated jute showed 84% 2, 4-D removal efficiency. The 2,4-D removal of the biosorbent was confirmed from FTIR and 13 C NMR analyses. The adsorption process was found to be spontaneous and effective over a pH range between 2 and 8. Maximum 2,4-D removal capacity of treated jute was found to be 38.5 mg/g. Treated jute was found to remove 2,4-D from aqueous media economically and efficiently through polar–polar and non-polar–non polar interactions. No sludge was produced during 2,4-D removal with treated jute nor did the process introduce deleterious characteristics, e.g ., hardness and odor to the treated water. [ABSTRACT FROM AUTHOR]

Novel soluble PEG-imidazole compounds were synthesized and evaluated as thermal latent catalysts for the polymerization of diglycidyl ether of bisphenol A (DGEBA) under liquid–liquid or liquid–solid (≥ PEG1000) two phase systems. Soluble PEG-imidazole homogeneous catalysts were used to cure epoxy resin system for the investigation of their thermal latency and storage stability. From the results, the PEG200-imidazole catalyst showed better thermal latency than PEG400-imidazole, PEG600-imidazole and PEG1000-imidazole. Concerning the glass transition temperature ( T g ), the use of novel PEG200-imidazole and PEG600-imidazole catalysts provided complete or near complete curing systems in the temperature range about 155 °C. Results from the cure activation energy and the viscosity-storage time of these catalysts, the order of thermally latent activity was PEG200-imidazole ( 1 ) > PEG400-imidazole ( 2 ) > PEG600-imidazole ( 3 ) > PEG1000-imidazole ( 4 ) > 1-cyanoethyl-2-ethyl-4-methylimidazole (2E4MZ-CN) > imidazole. [ABSTRACT FROM AUTHOR]

The use of asbestos fibre is being avoided due to its carcinogenic nature that might cause health risks. A new brake pad produced using banana peel waste to replace asbestos and Phenolic resin (phenol formaldehyde), as a binder was investigated. The resin was varying from 5 to 30 wt% with an interval of 5 wt%. Morphology, physical, mechanical and wear properties of the brake pad were studied. The results show that compressive strength, hardness and specific gravity of the produced samples were seen to be increasing with an increase in wt% of resin addition, while oil soak, water soak, wear rate and percentage charred decreased as the wt% of resin increased. Overall samples, containing 25 wt% in uncarbonized banana peels (BUNCp) and 30 wt% in carbonized (BCp) gave better properties. The result of this research indicates that banana peel particles can be effectively used as a replacement for asbestos in brake pad manufacture. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the bondability of birch ( Betula verrucosa Ehrh.) veneer subjected to different surface treatments (chemical treatment, short term thermo-mechanical densification, and combination of these two processes) using phenol-formaldehyde (PF) resin with the aim of improving bonding during the production of plywood. Four chemical agents (hydrogen peroxide, aluminium potassium sulphate, potassium carbonate, and potassium permanganate) were used for chemical treatment of the veneer surface. The veneer samples were thermo-mechanically densified between heated plates of a laboratory press. The results revealed that short term thermo-mechanical densification and combined chemical and thermo-mechanical pre-treatment of the veneer surface prior to the resin application reduced the glue spread (a 33% reduction) and improved the bondability of the veneer. The obtained shear strength values for all of the studied treatments exceeded the standard requirements (1·0 MPa), and the properties of the plywood samples satisfied the European standard EN 314-2. [ABSTRACT FROM AUTHOR]

Three functionalized ionic liquids (ILs) of [HeMIM]Cl, [CeMIM]Cl, and [AeMIM]Br that can dissolve corn stalk were synthesized and characterized via Fourier transform infrared spectroscopy (FTIR) and 1H NMR. The dissolved corn stalk was in situ blended with phenol and formaldehyde to produce modified phenolic resin composites. The resulting composites were characterized via FTIR, differential scanning calorimetry, and X-ray diffraction analysis, and tested for their mechanical properties. In addition, the effects of ILs on the dissolution rate of corn stalks and on the mechanical properties of the modified phenolic resin were investigated as well. The results showed that the synthesized ILs presented good solubility toward corn stalk at the optimum temperature of 90°C. After modification with corn stalk dissolved in ILs, the mechanical properties of phenolic resin were significantly improved. At the same conditions, the phenolic resin modified with [AeMIM]Br presented the lowest concentration of free formaldehyde and the best mechanical properties, in which the tensile strength and impact strength were improved from 3.28 MPa and 0.93 kJ/m² to 9.36 MPa and 5.74 kJ/m², respectively, but the hardness only changed slightly. [ABSTRACT FROM AUTHOR]

The susceptibility and characteristics of biological degradation of lignocellulosic fibers, such as sisal fibers, are presented in this study using a modified soil burial test (SBT) protocol. The biodegradation profile of untreated sisal fibers as well as of fibers treated with an alkaline emulsion of neem oil and phenolic resin was evaluated by estimating the enzymatic activities during the exposure of fibers to a soil/compost mix. Observation of the results indicated that biodegradation of the fibers was predominated by enzymatic hydrolysis of amorphous materials followed by degradation of crystalline cellulose. It was also evident that "oil-resin" treatment makes the fibers more resistant to biodegradation owing to the removal of amorphous materials, enhanced hydrophobicity, and possible chemical alteration of the surface hydroxyl groups of the fiber surface. This research aims to establish a systematic knowledge on the biodegradation profile of fiber components using a state-of-the-art protocol for SBT. [ABSTRACT FROM AUTHOR]

Chestnut hydrolysable tannins are phenolic materials that have been considered too unreactive to compete in the phenolic resin adhesives market for exterior boards for the building industry. However, an article in 1973 describing 3 years of industrial application of chestnut hydrolysable tannins during the first oil crisis indicated that this was not the case. This previous work has been extended by using superior phenolic resins formulations and producing phenol-formaldehyde-chestnut tannin adhesives where a substitution of up to 80% of the phenol is possible with remarkably good results. The reactions involved were clarified by 13C NMR and MALDI-TOF mass spectrometry. [ABSTRACT FROM AUTHOR]

About 50 million tons of lignin are produced annually in the pulping industry worldwide. A traditional example for lignin research is its use as a resin additive in wood based panels. The aim of this study was to find out why technical lignin has not so far succeeded in substituting for phenolic resins in the wood based panel industry. Interviews were carried out using a multistage expert interview approach adapted from Delphi methods. After the principal factors were identified and verified, quantitative data were taken for the valuation. Technical product properties received the highest ratings by the consulted experts, followed by security of supply, price difference and productivity, which received almost the same overall ratings. Interestingly, researchers rated security of supply much lower than the industry representatives. Depending on fulfilment of criteria identified, the experts expected that between 10 and 30% of phenolic resin can be potentially substituted within the next 10 years. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute 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.)

Abstract: Vitroperm (Fe73Cu1Nb3Si16B7) 800 flaky powder was studied from viewpoint of granulometric composition, particle morphology, density and resistivity. Composites based on Vitroperm powder and phenol-formaldehyde thermosetting resin were prepared. Physical properties of five types of composites with different resin content were analysed. Characterization of the composites includes microstructure, mechanical, electrical properties and their relations. Physical properties are presented as a result of the technology of preparation and obtained microstructure of the composite. [Copyright &y& Elsevier]

Here we demonstrate the use of polymer derived activated carbons as the potential electrode material for Li/O2 batteries. The activated carbons were synthesized by sol-gel polycondensation of low cost phenol and formaldehyde followed by carbonization at 1050°C in an inert atmosphere and activation under CO2 to different degrees of burn off. Galvanostatic charge/discharge measurements performed on the activated carbon based electrodes show that discharge capacity increases with mesopore volume, with the highest discharge capacity of 1852 mAh/g obtained for the carbon having the highest mesopore volume of 1.8717 cm³/g. Galvanostatic rate capability tests show that discharge capacity of the cell decreases with increasing discharge rates significantly. [ABSTRACT FROM AUTHOR]

Abstract: Imidazole with various molecular weights poly(ethylene glycol)s, including PEG1000, PEG2000, and PEG5000, was blended and evaluated as thermal latent catalysts for the polymerization of diglycidyl ether of bisphenol A (DGEBA) under liquid–liquid or liquid–solid two phase systems. The thermal latency and storage stability properties of DGEBA resin cured by 1–5wt% of molecular weight imidazole/PEG complexes were measured by viscometer, differential scanning calorimetry (DSC), and TGA. Based on the viscosity–shear rate results, we found the 1–3wt% amount of imidazole/PEGs showed the better thermal latency in the thermal polymerization system. From the cure activation energy and the viscosity–storage time of these complex catalysts, the order of thermally latent activity was imidazole/PEG1000 (2)>imidazole/PEG5000 (4)>imidazole/PEG2000 (3)>imidazole. Concerning the glass transition temperature (T g), the use of imidazole/PEG complex catalysts provided complete or near complete curing systems in the temperature range about 150°C. [Copyright &y& Elsevier]

Abstract: This paper describes an activation-free preparation of porous carbon by carbonization of a phenolic resin (PF) containing pore formers such as m-phthalic acid (PA), trimesic acid (TMA), and phloroglucinol (PG). Monitoring of their carbonization behaviors by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) suggested that PA and TMA, which have carboxylic functional groups, decomposed as single components, i.e., they had little interaction with PF. This left pores in the obtained carbon, as shown by N2 adsorption/desorption measurements. PG, which has phenolic groups, can interact strongly with PF, and no porous structure developed in PG/PFC. This strong interaction could prevent PG from decomposing individually and leaving pores in the carbon. It was also suggested that the presence of phenolic groups might cause interactions in the blend; we therefore suggest that pore formers with carboxyl groups would be appropriate in polymer blend carbonization techniques. [Copyright &y& Elsevier]

Abstract: Formaldehyde and VOC emissions from wood-based panels are recognized as one of the major causes of poor indoor air quality. These emissions may be strongly influenced by the raw materials and manufacturing techniques of the panels. However, there is very little published information regarding this issue. In this study we determine and compare formaldehyde and VOC emissions, including their species and content, at different manufacturing stages of wood-based panels such as urea-formaldehyde resin, wood chip, wood fiber after resin application, medium density fiberboard, and phenol-formaldehyde resin. We found that: (1) in total, 34 individual VOCs were identified, but none of them were in all the specimens, indicating considerable VOC species changes during the manufacturing process; (2) the formaldehyde in wood-based panels came primarily from urea-formaldehyde resin, and there existed a linear relationship between the formaldehyde content in resins and formaldehyde specific emission rate from wood-base panels; (3) VOCs in wood-based panels mainly came from the wood chips; (4) the drying and hot-pressing techniques were helpful in reducing the formaldehyde and VOC emissions from wood-based panels. Some suggestions are presented for the control of formaldehyde and VOC emissions from wood-based panels during the manufacturing process. [Copyright &y& Elsevier]

Phenolic-resin-based monolithic porous carbon (MPC) with large pores of about 2 μm in diameter has been prepared and evaluated as a possible substrate for the nickel hydroxide electrode. It has been observed that the MPC is basically electrochemically stable in the voltage range in which the nickel hydroxide electrodes operate. The Ni(OH)2 materials are loaded into the MPC using cathodic electrodeposition from the nickel nitrate solutions. This is performed by pulsing square-wave electrodeposition at room temperature. The ohmic drop of the MPC-Ni(OH)2/NiOOH electrodes during the charge-discharge process is largely due to their relatively low conductivity. The initial charge-discharge characterization of the MPC-Ni(OH)2/NiOOH electrodes shows that the specific capacity of the electrode material (SCEM) reaches 115 mAh·g-1 in terms of the total electrode weight. The above mentioned value is considerably higher than that of state-of-the-art sintered Ni-Ni(OH)2/NiOOH electrodes. Thus, it can be suggested that the MPC is a promising lightweight matrix for the Ni(OH)2/NiOOH electrodes with a focus on acquiring high weight specific energy for application in nickel-based alkaline batteries. [ABSTRACT FROM AUTHOR]

Nanosized LiFePO4 particles coated by uniform thin polyacene layer are synthesized from a pretreatment of FePO4·2H2O. The polyacene layer arises from carbonization of the phenolic-formaldehyde resin which is in situ polymerization to coat the amorphous FePO4·2H2O. The particle sizes of the LiFePO4 /polyacene nanocomposite are in the range of 20-60 nm. This LiFePO4/polyacene nanocomposite delivers discharge capacities of 142, 135, 124, 110 and 80 mAh g-1 at 1 C, 2 C, 5 C, 10 C and 20 C, respectively. The cyclic voltammetry curve and electrochemical impedance spectroscopy reveal low polarization of LiFePO4/polyacene due to the complete coating of polyacene layer on the nanosized LiFePO4 particles. Also the LiFePO4/polyacene nanocomposite shows good electrochemical performances in a wide temperature ranging from -20°C to 60°C. [ABSTRACT FROM AUTHOR]

Abstract: The use of solid sorbents for precombustion CO2 capture, which implies the removal of CO2 from the shifted-syngas prior to electricity generation, has acquired increasing interest in recent years. As an alternative method for precombustion CO2 capture, adsorption can be considered a promising technology, offering potential energy savings compared to absorbent systems. Solid sorbents are currently used in pressure swing adsorption (PSA) systems for the purification of hydrogen in petrochemical industries. In the present work, phenol formaldehyde resin-based adsorbents have been prepared to be applied in precombustión CO2 capture applications. The produced carbons showed superior performance when compared to commercial CO2 adsorbents and a great selectivity towards CO2. [Copyright &y& Elsevier]

Abstract: Laser cutting is the most widely implemented application of lasers in industry. The many advantages of this process stimulate users in industry to cut many different materials, such as wood and wood composites –particleboard, plywood, etc.–, which are being cut with excellent results and productivity. Phenolic resins boards are a new substitute of wood in highly aggressive environments. In the present work we study the feasibility of CO2 lasers to cut phenolic resin boards and assess the potential health hazards of the vapours and residues produced, since its thermal degradation may produce toxic organic vapors. [Copyright &y& Elsevier]