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Sensing is the process of detecting and monitoring any physico‐chemical environmental parameters. Herein, new self‐powered iontronic sensors, which utilize touch‐induced ionic charge separation in ionically conductive hydrogels, are introduced for potential use in object mapping, recognition, and localization. This is accomplished using high‐resolution stereolithography (SLA) 3D printing of stacked ionic assemblies consisting of discrete compartments having different ion transport properties. The latter assemblies readily allow programming the output voltage magnitude and polarity by means of variations in ion type, charge density, and cross‐linking density within the iontronic device. Voltages of up to 70 mV are generated on application of compressive strains of as much as 50% (≈22.5 kPa), with the magnitude directly proportional to stress, and the polarity dependent on the sign of the mobile ion. As a proof‐of‐concept demonstration, the resulting touch sensors are integrated on the fingertip to enable the tactile feedback, mimicking the tactile perception of objects for recognition applications. In addition, it is proposed that streaming potential is the underlying mechanism behind the iontronic touch sensors. The electromechanical response is therein consistent with a streaming potential model. [ABSTRACT FROM AUTHOR]

A simple approach towards the compatibilization of polylactide (PLA) and hydroxyapatite (HAp) nanoparticles nanocomposites is here presented. An amphiphilic diblock copolymer, consisting of poly(ethylene glycol) (PEG) and PLA block was prepared and used to form an interphase between PLA matrix and HAp nanofiller. This copolymer was next mixed with HAp to intimly deposit PEG block on the HAp surface. Effective hydrophobization via PLA chains presence on the surface of the modified nanoparticles was attested via dispersion test in chloroform. Finally, the as modified HAp nanoparticles were blended in PLA. Thermal analyses showed a Tg superior to human body temperature. Dynamic mechanical and morphological analysis attested for improved dispersion and deagglomeration state of the nanoparticles in PLA. Interfacial mechanical properties studies recorded an increase of 150% in compressive modulus compared with neat PLA. In vitro bioactivity assay showed beneficial effect on the mineralization process in simulated body fluid when the interphase is created. This improvement of mechanical properties and bioactivity combined with a simple production process as extrusion make these materials suitable choice for potential load bearing applications. [ABSTRACT FROM AUTHOR]

The introduction of dynamic covalent chemistry into the field of polymer chemistry has resulted in a new class of network polymer materials named covalent adaptable networks (CANs). These new materials have effectively bridged two antagonistic materials, that is, conventional thermoplastic and thermoset polymers together, thanks to these dynamic exchangeable covalent bonds, making them recyclable. In this work, we report a catalyst‐free reprocessable polybenzoxazine‐polyurethane thermosetting system with activation of carbamate dynamic bond exchange. The curing characteristics and properties of this biobased polybenzoxazine‐polyurethane network have been determined by Fourier transform infra‐red (FTIR), differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMA). Moreover, the tests of the recyclability of the material were successfully achieved under mild reprocess conditions (130°C, 10 min) thanks to the formation of abundant free phenolic hydroxyl groups. This work provides a promising potential for industrial applications as a new recyclable and reprocessable thermosetting polybenzoxazine material. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethanes (TPUs) bear tunable chemistry offering the possibility to develop a rich palette of physio‐mechanical properties, making the materials suitable for various fields of application. The great variety in TPUs properties comes from the choices of the monomers and the reaction conditions. Herein, the mechanical properties of the developed TPUs are tailored, while fine‐tuning the hard and soft segment molar ratio, as well as the reaction conditions. TPUs are synthesized from 4,4′‐methylenebis(phenyl isocyanate), poly(tetrahydrofuran), and 1,4‐butanediol, and their thermal and mechanical properties are fully characterized. The sample with the most appropriate mechanical properties that are suitable for catheter fabrication, is selected for the biomedical application. Quaternary ammonium salt is synthesized, and 0.5 mol% is incorporated in the TPU to confer antibacterial properties to the material while preserving its mechanical strength. The microbiological tests reveal the antibacterial effect of the developed materials against Staphylococcus aureus and Pseudomonas aeruginosa, as well as 80% SiHa cell viability, after 72 h of exposure, as part of the performed cytotoxicity studies. Finally, TPUs catheter prototypes fabrication is also proposed, applying an extrusion or injection molding approach for the production of biomedical devices with desirable mechanical properties. [ABSTRACT FROM AUTHOR]

Adding nanofillers Cloisite 30B (C30B) and Cloisite 15A (C15A) to poly(ethylene terephthalate) (PET)/poly(ε‐caprolactone) (PCL) (70/30, wt/wt) blends via melt blending can improve their phase morphology and change their interface properties. The effects of the different selective localization of clay on the structure and the morphologies are studied and evaluated by theoretical and experimental methods. It is found that C30B is selectively localized in PET and at the PET‐PCL interface, whereas C15A is mainly localized at the interface. Moreover, the changes in the rheological behavior of the blends are attributed to the formation of clay network‐like structures. X‐ray diffraction, scanning electron microscope, and transmission electron micrograph observations also evidenced an exfoliated and/or intercalated structure of C30B, and intercalated structure of C15A in the blend, together with significant morphology changes of the initially immiscible blend. The relative permeability to PET/PCL of the nanocomposites decreased with the increasing of nanoclays content. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48812. [ABSTRACT FROM AUTHOR]

This work aims at identifying defects called deformation heterogeneities developing in polylactide (PLA)‐based materials upon drawing at room temperature. The influence of the initial crystallinity and of the plasticization methodology (physical blending vs. reactive blending) on the type of defect is also investigated. Defects are characterized in situ by (a) calculating the volume strain from digital image correlation (DIC), (b) measuring their surface density from optical microscopy, and (c) assessing their scattering invariant from small‐angle X‐ray scattering. Complementary structural analyses are done by microcomputed X‐ray tomography and atomic force microscopy. Drawing is accompanied by crazing in the case of low‐crystalline PLA, cracking in the case of annealed PLA, no defect in the case of plasticized PLA by physical blending, and shear bands and cracking in the case of plasticized PLA by reactive blending. These observations are discussed based on the initial structural features of the materials. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1452–1468 Defects developing in PLA‐based materials upon drawing are studied by a multiscale and in situ approach. Low crystalline PLA exhibits crazing, while after annealing, tortuous defects are noted. These defects may be induced by the opening of crystallization‐induced cracks. Physical plasticization of PLA engenders no defect, while reactive plasticization of PLA induces shear bands and localized cracks. A multiscale correlation of defect characterization is performed in the case of crazing, showing the relevancy of this approach. [ABSTRACT FROM AUTHOR]

Abstract: The hydrolytic degradation of poly( l‐lactic acid)/poly(methyl methacrylate) (PLLA/PMMA) blends was carried out by the immersion of thin films in buffer solutions (pH = 7.24) in a shaking water bath at 60 °C for 38 days. The PLA/PMMA blends (0/100; 30/70; 50/50; 70/30; 100/0) were obtained by melt blending using a Brabender internal mixer and shaped into thin films of about 150 µm in thickness. Considering that PMMA does not undergo hydrolytic degradation, that of PLLA was followed via evolution of PLA molecular weight (recorded by size exclusion chromatography), thermal parameters (differential scanning calorimetry (DSC)) and morphology of the films (scanning transmission electron microscopy). The results reveal a completely different degradation pathway of the blends depending on the polymethacrylate/polyester weight ratio. DSC data suggest that, during hydrolysis at higher PMMA content, the polyester amorphous chains, more sensitive to water, are degraded before being able to crystallize, while at higher PLLA content, the crystallization is favoured leading to a sample more resistant to hydrolysis. In other words, and quite unexpectedly, increasing the content of water‐sensitive PLLA in the PLLA/PMMA blends does not mean de facto faster hydrolytic degradation of the resulting materials. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

New biobased plasticizers made of di‐functional glycidyl ether epoxy cardanol (ECard) were investigated to improve the ductility of renewable poly(lactide) (PLA). Compatibility between PLA and ECard was achieved out through in situ reactive grafting strategy catalyzed with Ethyltriphenyl phosphonium bromide (ETPB) using twin‐screw extruder. In absence of catalyst, ECard forms domain ill‐dispersed in the PLA matrix due to the high incompatibility between both phases. When ETPB is added as catalyst domain size distribution of the plasticizer decreased, indicating an enhanced compatibility due to the reactive grafting of a fraction of ECard plasticizer onto PLA backbone. Although all plasticized PLA specimens exhibit lower glass transition temperature, lower elastic/tensile modulus, lower yield stress, and higher strain at break, the reactive blend containing the lowest amount of catalyst, that is, 0.02 phr, exhibited the highest ductility behavior. POLYM. ENG. SCI., 58:E64–E72, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract: In this work, the synthesis and characterization of triple‐shape and two‐way shape‐memory effect of novel poly(ester‐urethane)s (PURs) made of a poly(ε‐caprolactone) (PCL) and poly(ω‐pentadecalactone) (PPDL) segments and N,N‐bis(2‐hydroxyethyl)cinnamide (BHECA) monomer by reactive extrusion (REx) is reported. PCL and PPDL are chosen as semicrystalline segments because of their inherent ability to undergo tensile elongation upon cooling, as prerequisite for the two‐way shape‐memory effect. BHECA is used as the “cross‐linker” due to its ability to participate in reversible [2+2] cycloaddition reaction and to mainly maintain the crystalline features of semicrystalline precursors within these PURs. This novel simple strategy is considered extremely versatile and adaptive because of the possibility to vary crystallizable segments and coupling agents, thus paving the way to the design of a multitude of triple (or more) shape‐memory polymers with two‐way behavior. Feasibility with PURs containing PCL, PPDL, and BHECA is demonstrated by adjusting the shape‐memory behavior (one and two‐way effects), and studying the structure–property relationships of the resulting PURs by DSC, DMTA, and 2D wide angle X‐ray scattering analyses while varying the weight composition of the two semicrystalline segments. [ABSTRACT FROM AUTHOR]

In this work, a systematic study on the humidity-activated shape memory properties of dual-responsive shape memory bionanocomposites with both humidity- and thermally-activated shape memory effects is reported. The study is performed through humidity-mechanical cycles in an Instron machine with a temperature chamber equipped with an ultrasonic humidity generator. In particular, the bionanocomposites studied are based on blends of ethylene-vinyl acetate (EVA) and thermoplastic starch reinforced with natural bentonite. In our previous work, thermomechanical cycles are performed by using EVA-induced crystallization and a preliminary humidity-activated shape memory test is designed. Herein, the shape memory results of both blends and their nanocomposites reflect the very good ability to humidity-activated recover of the initial shape with values higher than 80%. Moreover, the ability to fix the temporary shape of this systems is very good, especially when nanofillers are added. The compatibilizer effect of natural bentonite is demonstrated by means of different techniques such as scanning emission microscopy and mapping by confocal Raman spectroscopy. [ABSTRACT FROM AUTHOR]

A multiscale characterization approach is developed to resolve the structure of inclusions in polylactide (PLA) plasticized with acrylated poly(ethylene glycol) (acrylPEG) by reactive extrusion. Scanning transmission X-ray microscopy (STXM) coupled with near-edge X-ray absorption fine structure (NEXAFS) nanospectroscopy demonstrates that these inclusions have a core-shell morphology. This technique also proves that the inclusions consist of polymerized acrylPEG (poly(acrylPEG)), which is also confirmed by elastic modulus measurement using an atomic force microscope. The shell consists of poly(acrylPEG)-rich domains, while the core is less rich in the polymerized plasticizer. Upon drawing, the density of the inclusion's core and shell markedly decreases as shown by microcomputed X-ray tomography measurements, and no inclusion-matrix debonding is observed. At the same time, sub-micrometer cracks are noted between inclusions by STXM/NEXAFS imaging, which may result from the presence of crosslinking points restricting the local chain mobility. Novel knowledge about the reactive extrusion-induced PLA structure is released. [ABSTRACT FROM AUTHOR]

Developing intrinsic self-healing polymeric materials is of great interest nowadays to extend material lifetime and/or prevent the replacement of damaged pieces. Spontaneously humidity-sensitive healable polymer network built around dynamic covalent B−O bonds was templated by using iminoboronate-based boroxine derivatives. Taking advantage of the dynamic boroxine/boronic acid equilibrium and iminoboronate chemistry, it is possible to construct polymeric materials able to self-heal without requiring any energy-demanding external activation. Interestingly, this novel family of iminoboronate adduct-based materials can be readily produced by a relatively simple and straightforward synthesis between boronic acid and diamine-based compounds, paving the way to coatings that are self-healable at ambient humidity. [ABSTRACT FROM AUTHOR]

A novel biobased plasticizer made of cardanol is designed for poly(lactide) (PLA). This cardanol-derived plasticizer, i.e., methoxylated hydroxyethyl cardanol (MeCard), is synthesized through methoxylation of the double bonds on the side chain of cardanol, and characterized by 1H NMR and mass spectrometry. The plasticization effect of MeCard on the molecular structure, morphology, thermal and mechanical properties of PLA is evaluated and compared to that of a commercial cardanol, i.e., hydroxyethyl cardanol (pCard). The plasticization efficiency of MeCard is demonstrated by a substantial decrease of the glass transition temperature and storage modulus together with a significant increase of the elongation at break as compared to neat PLA. Moreover, MeCard exhibits higher plasticization performance than pCard toward PLA. Such behavior is related to a higher miscibility and compatibility between PLA and MeCard thanks to the methoxylation of the double bonds on the side chain of cardanol as shown by SEM micrographs. [ABSTRACT FROM AUTHOR]

ABSTRACT Technical renewable poly( l-lactide) (PLA)-based blends represent an elegant way to achieve attractive properties for engineering applications. Recently, the miscibility between PLA and poly(methyl methacrylate) (PMMA) gave rise to new formulations with enhanced thermo-mechanical properties but their high brittleness still remains a challenge to be overcome. This work here focuses on rubber-toughened PLA/PMMA formulations for injection-molding processes upon the addition of a commercially available ethylene-acrylate impact modifier (BS). The miscibility between PLA and PMMA is not altered by the presence of BS but the incorporation of BS (17% by weight) into a PLA/PMMA matrix could enhance both ductility and toughness of PLA/PMMA blends for PMMA content up to 50 wt %. An optimum range of particle sizes ( dn ∼0.5 µm) of the dispersed domains for high impact toughness is identified. These bio-based ternary blends appear as promising alternatives to petro-sourced blends such as ABS-based blends in engineering injection-molding parts. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43402. [ABSTRACT FROM AUTHOR]

ABSTRACT Poly(lactic acid) (PLA) nanocomposites characterized by multifunctional end-use properties are of high interest as new biosourced materials for the production of smart films, fibers, and injection-molded components. In this work, PLA-ZnO nanocomposites designed for the extrusion of films were obtained by melt-compounding PLA with up to 5 wt % ZnO rod-like nanoparticles, nanofiller previously surface-treated with a specific silane (triethoxycaprylylsilane). To improve the processing and performances of nanocomposites such as their stability at high temperature, the addition of a selected chain-extender (CE) was considered. It was revealed that the co-addition of nanofiller (ZnO) and epoxy functional styrene-acrylate oligomeric CE (Joncryl® ADR 4300F) leads to a very significant enhancement of the properties (molecular, rheological, thermal, etc.) of PLA-ZnO nanocomposites. After addition of 1% CE into nanocomposites, the PLA molecular weights were found to be nearly twofold higher, while the isothermal tests (at 220 and 240°C) confirmed a significant increase in thermal stability. Because the CE plays a key role in limiting the degrading effects of ZnO, due to a gain in melt viscosity and increased molecular mass, a better ability to process nanocomposites by extrusion was found. The good nanofiller dispersion and specific end-use characteristics owing to the presence of ZnO nanoparticles (such as UV shielding) were again confirmed on extruded films. These developments are being viewed as a promising approach that can open new perspectives in the application of PLA-ZnO nanocomposites with specific end-use properties (UV protection, antibacterial, gas-barrier, and self-cleaning) at larger scale. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42480. [ABSTRACT FROM AUTHOR]

This work aimed at identifying the tensile deformation mechanisms of an original grade of plasticized polylactide ( pPLA) obtained by reactive extrusion. This material had a glass transition temperature of 32.6 °C and consisted of a polylactide ( PLA) matrix grafted with poly(acryl-poly(ethylene glycol)) (poly(Acryl- PEG)) inclusions. pPLA behaved like a rubber-toughened amorphous polymer at 20 °C, and its tensile behavior evolved toward a rubbery semicrystalline polymer with increasing temperature. The drawing of pPLA involved orientation of amorphous and crystalline chains, crystallization, and destruction of crystals. It was found that crystal formation and crystal destruction were in competition below 50 °C, resulting in a constant or slightly decreasing crystallinity with strain. Increasing temperature enhanced crystal formation and limited crystal destruction, resulting in an increased crystallinity with the strain level. Drawing yielded a transformation of the initial spherical poly(Acryl- PEG) inclusions into ellipsoids oriented in the tensile direction. This mechanism may engender the formation of nanovoids within the inclusions due to a decreased density, assumed to be responsible for the whitening of the specimen. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The co-addition of rubber-like poly( ε-caprolactone- co-D, l-lactide) (P[CL- co-LA]) as impact modifier and N, N′-ethylenebis(stereamide) (EBS) as nucleating agent has here been investigated to tailor both the crystallization and toughness of resulting polylactide (PLA)-based materials. In this work, 10 wt% of P[CL- co-LA] copolymer and different concentrations of EBS were added into PLA by twin-screw extrusion (in a micro-compounder) in order to establish the mechanical performances of the resulting blends upon the nucleating agent content. Crystallization behavior and impact toughness of PLA-based materials were both enhanced and were ascribed to a clear alteration of the matrix crystallinity, spherulitic growth rate, and crystal structure upon the nucleating agent content. As a result, toughness of PLA-based materials was considerably enhanced up to, at least, 11 times with respect to neat PLA. Such improvement of the fracture resistance upon the extent of PLA crystallinity was related to a change in the toughening mechanism from crazing to shear-yielding (combined with crazing) through the deformation of spherulites, promoting high energy dissipation pathways as crystallization occurs. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Among currently available bio-based polymers, polylactide (PLA) and its (nano)composites have interesting physical and mechanical properties (high tensile strength and stiffness, good processability, biodegradability...). However, they have relatively low thermal stability at high temperature, low toughness and are extremely brittle, all of these drawbacks being obstacles to their utilization in many engineering applications. In this study, PLA-halloysite nanotubes (HNT) nanocomposites are modified by co-addition of a plasticizer (tributyl citrate (TBC)), aiming at reaching mechanical properties suitable for automotive applications. Properties of nanocomposites at different plasticizer contents are characterized with the aim to reach the best compromise between high tensile and flexural strengths and rigidities (ascribed to the matrix and HNT) and impact resistance, ductility, crystallization rat,e and degree of crystallinity, in particular. Results show that plasticized PLA-HNT nanocomposites are very interesting bio-based alternatives for automotive applications, when the plasticizer content is carefully chosen. [ABSTRACT FROM AUTHOR]

To design high-performance poly(lactide)-based materials (PLA-based) with improved toughness, two approaches based on the reactive extrusion (REx) process are investigated and compared in the present study. The first approach relies upon a two-step procedure using a REx-polymerized poly(ethylene glycol) methyl ether acrylate, i.e., poly(AcrylPEG), as a highly-branched and compatible impact modifier for PLA. The free-radical polymerization proves to be very efficient with a peroxide initiator concentration of 1 wt%. The as-produced poly(AcrylPEG) is then melt-blended with PLA by extrusion. The resulting materials exhibit largely increase impact resistance (ca. 35 kJ/m2) in presence of 20 wt% poly(AcrylPEG) in comparison with neat PLA (2.7 kJ/m2), while moderate ductility (tensile elongation at break <40%) and limited plasticization effect are observed. The second 'one-step' approach consists in in situ grafting of AcrylPEG onto PLA backbone via a one-stage REx. The resulting materials exhibit substantially improved impact resistance (ca. 102 kJ/m2) for AcrylPEG loading of 20 wt%, high ductility (tensile elongation at break of ca. 150%) and efficient plasticization. A detailed characterization of the morphology of the materials has been performed using PF-QNM-AFM to better elucidate the structure-property relationships. POLYM. ENG. SCI., 55:1408-1419, 2015. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

To tune the toughness of PLA, a novel pathway to chemically modify PLA via reactive extrusion in the presence of 'reactive' PEG derivatives is proposed. PEG methyl ether methacrylate (MAPEG) and PEG methyl ether acrylate (AcrylPEG) are melt-mixed and extruded with PLA in the presence of 2,5-dimethyl-2,5-di( tert-butylperoxy)hexane (L101) as a free-radical initiator. Molecular characterization reveals that about 20 and 65%, respectively, of the initially introduced MAPEG and AcrylPEG can be grafted onto the PLA backbone. The plasticization effect is demonstrated by a significant decrease of the glass transition temperature and storage modulus together with a significant increase of the elongation at break as compared to neat PLA. [ABSTRACT FROM AUTHOR]

ABSTRACT Nanocomposites of equimolar enantiomeric polylactide blends with multiwall carbon nanotubes (MWCNTs) were prepared by a solvent casting/sonication procedure. The first objective of the study was to investigate the effect of MWCNTs as nucleating agents for the selective crystallization of the polylactide (PLA) stereocomplex to obtain PLA-based nanocomposites. Transmission Electron Microscopy (TEM) studies revealed large agglomerates and poor distribution of the non-functionalized MWCNTs within the matrix. To enhance the compatibility between PLA and MWCNTs, pyrene-end-functionalized PLLA (py-end-PLLA) nanocomposites were prepared because of the ability of the pyrene moieties to interact with the MWCNTs via π−π stacking, and were subsequently blended with poly( d-lactide) (PDLA) to investigate the possibility of achieving nanocomposites in which the enantiomeric blend crystallizes as stereocomplex. The resulting nanocomposites were characterized by Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), TEM, and Nuclear Magnetic Resonance Spectroscopy (NMR), revealing that MWCNTs were efficient nucleating agents for the overall crystallization of the blends. Interestingly, full stereocomplexation could be achieved with the aid of soft specific thermal treatments. According to these results, the addition of small amounts of MWCNTs combined with a mild thermal treatment might extend the processing window for the preparation of polylactides exclusively crystallized in the stereocomplex form. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4327-4337, 2013 [ABSTRACT FROM AUTHOR]

Herein, we report the first example of a supramolecular carbon nanotube (CNT)-based magnetic depolluting agent for divalent metal ion (M2+) removal from aqueous solutions. In particular, magnetic multi-walled carbon nanotubes (m-MWCNTs) coated with poly(vinylpyridine) (PVPy) self-aggregate in aqueous solutions that contain divalent metal ions (such as Zn2+, Cu2+ and Pb2+) to form tight insoluble bundles in which the M2+ ions remain trapped through pyridyl-M2+-pyridyl interactions. Magnetic filtration ultimately affords the efficient separation of the depolluted solution from the precipitated M2+-CNT agglomerates. Upon acid treatment, the supramolecular threads could be disassembled to afford the free CNT-polymer hybrid, thus allowing recycling of the depolluting agent. All materials and complexation/decomplexation steps were thoroughly characterised by using thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), transmission and scanning electron microscopy (TEM and SEM, respectively). The quantification of the M2+ residual concentrations in water was evaluated by using inductively coupled plasma optical emission spectroscopy (ICP-OES), which showed that, depending on the metal cation, this material can remove up to 99 % of the contaminant. [ABSTRACT FROM AUTHOR]

Imidazolium end-functionalized poly(butyl acrylate) and polystyrene (co)polymers (Im-PnBuA, Im-PSty, and Im-PnBuA- b-PSty are synthesized via ATRP. The controlled character of the polymerization reactions is highlighted by SEC and MALDI-TOF MS analyses. Subsequently, the polymers are tested as dispersing/compatibilizing agents for CNTs in polymer matrices. When CNTs are challenged with a mixture of Im-PnBuA and Im-PSty, the CNTs are mainly located in the PnBuA phase. In contrast, the Im-PnBuA- b-PSty block copolymer enables CNT confinement in the PSty phase. By selecting the proper ω-imidazolium polymer, it is possible to direct the CNT confinement toward a specific polymer phase within polymer mixtures. [ABSTRACT FROM AUTHOR]

Biodegradable nanoscale-reinforced starch-based products were prepared from an in situ chemically modified thermoplastic starch and poly(butylene adipate -co-terephthalate) (PBAT) through reactive processing. Natural montmorillonite (hydrophilic Cloisite Na) and organophilic Cloisite 30B were studied. In situ chemically modified thermoplastic starch (MTPS) was first prepared starting from (nano)clay (previously swollen in glycerol as plasticizer), and maleic anhydride (MA) as an esterification agent. Then, these nanoscale-reinforced MTPS was reactively melt-blended with PBAT through transesterification reactions promoted by MA-derived acidic moieties grafted onto the starch backbone. The tensile and barrier properties of resulting (nano)composites were studied. High-performance formulations with superior tensile strength (>35 MPa as compared with 16 MPa for the PBAT- g-MTPS copolymer) and break elongation (>800%) were obtained, particularly with Cloisite30B. Better water vapor and oxygen barrier properties of nanoscale-reinforced MTPS- g-PBAT were achieved rather than the PRECURSORS. Wide angle X-ray diffraction and transmission electronic microscopy analyses show that partial exfoliation of the clay platelets was observed within the PBAT- g-MTPS graft copolymer-Cloisite 30B nanocomposite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

The abiotic UV-degradation behavior of oxodegradable LDPE was investigated in the presence of thermoplastic pea starch (TPPS) in this study. Oxodegradable LDPE was first melt-blended with thermoplastic pea starch (TPPS) using an internal mixing chamber to enhance the abiotic oxidative degradation of oxodegradable LDPE. Because of their different affinity, maleated polyethylene was added as compatibilizer. Tensile properties, thermal properties, and morphology of resulting melt-blends were determined at different content in TPPS. High content in TPPS (40 wt %) could be readily added to oxodegradable LDPE without affecting the tensile properties of resulting melt-blends. UV-ageing studies on compatibilized TPPS/oxodegradable LDPE melt-blends were carried out by Attenuated Total Reflectance infrared spectroscopy (ATR-FTIR), Dynamic Thermomechanical Analyses (DMTA) and Differential Scanning Calorimetry (DSC) under abiotic conditions. These results suggested a synergistic effect on the UV-ageing of TPPS-based melt-blends provided by both components during the first stage of UV-irradiation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011. [ABSTRACT FROM AUTHOR]

As an industrial approach, the extrusion process gave rise to the fabrication of TPU catheter prototypes. Then, the incorporation of only 0.5 mol% of a biologically active ammonium salt unit endowed the biomaterial with antibacterial against microorganisms such as Staphylococcus aureus and Pseudomonas aeruginosa. The cover image by Franck Meyer and his co-authors highlights the fabrication of thermoplastic polyurethanes (TPUs) targeting the development of catheters for direct biomedical application. [Extracted from the article]

The article discusses the incorporation of starch into plastic materials in order to create environmentally-friendly and biodegradable products while maintaining plastics performances. The authors examine the use of maleated thermoplastic starch (MTPS) in extrusion melt-blending in blown-film applications. MTPS is melt-blended with poly(butylene adipate-co-terephthalate) (PBAT), the article states. Topics include an increased interfacial area for grafting reactions and formations of graft copolymers generated by acid-promoted transesterification reactions.