Polymer Chemistry最新文献

To overcome the environmental and resource constraints of petroleum-based polyisobutylene (PIB), the cationic random copolymerization of isobutylene (IB) with the sustainable and renewable monomer β-pinene (Bp) was systematically investigated using an Al₂Et₃Cl₃/trace water initiation system. Through condition optimization (T = −80 °C, [Al₂Et₃Cl₃] = 1.00 × 10⁻² mol L⁻¹, n_IB : n_Bp = 98 : 2), IB-co-Bp copolymers with high molecular weight (M_n was up to 7.86 × 10⁴ g mol⁻¹) were successfully synthesized. This random copolymer structure and reaction mechanism were elucidated via¹H-NMR and DFT. The structural characteristics, thermal properties and mechanical properties of the copolymer were systematically investigated to clarify its composition-property relationships. More importantly, dynamic mechanical analysis of the vulcanized samples demonstrated that Bp incorporation significantly influenced the copolymer's viscoelastic behavior and network structure. The vulcanization of IB-co-Bp copolymers was shown to effectively enhance its damping performance, thus providing a novel strategy for high molecular weight bio-based PIB and a sustainable pathway for developing advanced elastomers.

Pressure sensitive adhesives (PSAs) are widely used materials in a number of applications, such as sticky notes and tapes, but for most commercial products they are derived from petrochemicals. Here, a series of pentablock polymers, with an ABABA structure featuring poly(cyclohexene oxide-alt-phthalic anhydride) ‘A’ blocks and poly(ε-decalactone) (PDL) ‘B’ blocks, are prepared as pressure-sensitive adhesives from bio-sourced monomers. The pentablock polymers are prepared by controlled polymerisation techniques, using a single catalyst, in a one-pot process. Polymer properties are tuned through varying the hard block (A) content between 16–39 wt%. Below 25 wt% hard block, the pentablock polymers show low-tack adhesive performance (0.2–0.6 N cm⁻¹) and are removed by adhesive failure. Their adhesive performance compares favourably to low-tack commercial adhesives.

Poly(olefin sulfone)s (POSs), formed via alternating copolymerizations of sulfur dioxide (SO₂) and olefins, remain understudied with respect to systematic structure–property relationships. In this work, we report the synthesis and thermal characterization of five POS copolymers and 24 terpolymers derived from linear alkenes (1-hexene, 1-decene) and cycloalkenes (cyclopentene, cyclohexene, norbornene). All polymers were prepared by free radical polymerization at −30 °C initiated by tert-butyl hydroperoxide. Molecular characterization by ¹H and ¹³C NMR spectroscopy, FTIR spectroscopy, and size-exclusion chromatography with multi-angle light scattering (SEC-MALS) confirmed polymer structures and high molecular weights (weight-average molecular weight, M_w = 100–8000 kg mol⁻¹). Thermogravimetric analysis showed decomposition temperatures at 50% weight loss (T_d,50%) for the copolymers ranged from 292 to 317 °C, with the highest stability observed in the norbornene-containing copolymers and terpolymers. Differential scanning calorimetry revealed glass transition temperatures (T_g = 46–184 °C) that increased systematically with the incorporation of cyclic comonomers. These results show systematic structure–property relationships in POS co- and terpolymers and demonstrate how polymer structure governs thermal behavior, providing guidance for the design of thermally robust sulfone-based polymers for advanced applications.

Hydrogels are widely employed in biomedical applications such as drug delivery, tissue engineering, and wound healing due to their ability to mimic the properties of biological tissues. Here, the development of novel simultaneous interpenetrating network (SIN) hydrogels composed of polysarcosine (PSar) and polyethylene glycol (PEG), crosslinked through orthogonal photochemical reactions is reported. The PSar single network was formed by free-radical polymerization of methacrylate-functionalized PSar, while the second network was generated simultaneously from cinnamic acid-modified PEG via [2 + 2] cycloaddition. Comprehensive characterization revealed that the SIN hydrogels exhibit enhanced mechanical performance, including higher elongation at break, ultimate tensile strength, compressive strength, fracture strain, and Young's modulus, compared to the individual networks. Furthermore, rat mesenchymal stem cell assays confirmed superior cytocompatibility, with robust metabolic activity and proliferation on SIN hydrogels. Collectively, these findings demonstrate that PSar-based SIN hydrogels combine mechanical robustness with biocompatibility, highlighting their strong potential as functional materials for artificial tissue applications.

Vinyl ether-maleic anhydride (VEMAn) copolymers were chain extended with n-butyl acrylate (nBA) and tert-butyl acrylate (tBA) blocks using reversible addition–fragmentation chain transfer (RAFT) copolymerization. Subsequently, the copolymers underwent hydrolysis to synthesize vinyl ether-maleic acid (VEMA) copolymers with different tail structures. The nBA block yielded VEMA extended with an acrylic acid (AA) block after hydrolysis. The tBA block gave VEMA extended with a mixture of tBA and AA blocks. This study investigates the effect of VEMA hydrophilicity/hydrophobicity and monomer structure in the second block on the formation and properties of self-assembled lipid nanodiscs. In particular, the size of the polymer–lipid discs and their interaction with a model membrane protein, KCNE1. The findings indicate that both AA and tBA/AA VEMA blocks yield lipid discs, however copolymers with tBA/AA blocks tend to form relatively larger lipid nanodiscs potentially due to steric differences in the copolymer tail. The change in hydrophobicity of VEMA block copolymers affects the resulting dimensions of lipid nanodiscs; similarly, the type of lipid also influences the size of lipid discs. Electron Paramagnetic Resonance (EPR) studies revealed that these block copolymers do not affect the structural dynamics of the KCNE1 protein, confirming their suitability for membrane protein studies in native-like environments. This study demonstrates the compatibility of VEMA-block copolymers with membrane protein systems by enabling control over the size of lipid discs. Furthermore, it provides insight into the self-assembly understanding of these lipid nanodiscs and their interactions with membrane proteins.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively employed as a flexible conductive coating in diverse application fields. However, the existence of numerous weak electrostatic interactions within the PEDOT:PSS matrix presents a significant challenge to the material's stability. Herein, we demonstrate that a slight reduction in the charge density of the outer-shell polyanion can effectively inhibit the penetration of degradation-inducing molecules, preserving the structural integrity and electrostatic stability of the entire matrix. Specifically, reducing the polyanion's charge density lowers the electrostatic repulsion encountered by oxidant ions during the oxidative polymerization process, thereby accelerating the reaction kinetics and facilitating the formation of an enlarged PEDOT:polyanion matrix. The increased matrix size leads to a significant decrease in its specific surface area, thus effectively reducing the number of surface charges available for interaction with degradation-inducing agents such as 1,8-diiodooctane, chloroform, and water. Simultaneously, enhanced coulombic trapping of polarons was observed, providing a complementary mechanism that contributes to improved overall stability. Impressively, the PEDOT film demonstrates remarkable resistance to water immersion, maintaining structural integrity for over 40 days without evidence of exfoliation, swelling, or dissolution. This study offers a meaningful reference for improving the stability of PEDOT coatings via polyanion engineering.

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Compositional modifications of conducting polymer-based graft copolymers enable precise tuning of their properties, including conductivity, degradation and opto-electrochemical properties. This work investigates how the composition of poly(caprolactone)-graft-oligo(3-hexylthiophene)s, (P(CL-co-AVL)-g-O3HT), previously shown to be degradable, effects the morphological and opto-electrochemical properties of the copolymers. Effect of different grafting density and the length of the O3HT grafts on the material's properties were investigated using a range of advanced techniques, such as, spectroelectrochemistry, cyclic voltammetry, 2D-GIXRD and 4D-STEM. Short O3HT grafts (n = 15) yielded amorphous copolymers, whereas longer grafts (n = 30, 40) produced semi-crystalline material with distinct crystalline and amorphous redox signatures. High grafting density promoted formation of interconnected nanoscale O3HT crystallites. Thermal annealing (40–60 °C) or trace acetonitrile (1 vol%) in casting solutions enhanced intrachain order and crystallization, and, in turn, enhanced optoelectronic properties of the high-density, long grafts copolymers. These findings establish structure–property relationship in conducting polymer-based graft copolymers, guiding their macromolecular design, including for transient electronics.

Polyethylene terephthalate (PET), a dominant polymer in global plastic production, faces critical recycling challenges due to its persistence in ecosystems and limitations of conventional mechanical/thermal recycling. Upcycling PET waste into value-added polymers represents a transformative approach toward a circular plastics economy. This review systematically examines innovative strategies for chemically converting post-consumer PET into novel polymeric materials, thereby bypassing the performance degradation typically associated with traditional recycling. Key pathways include (1) depolymerization into monomers (terephthalic acid, ethylene glycol) for repolymerization into high-purity PET or advanced polyesters (e.g., biodegradable or bio-based variants), (2) transformation into functional polymers such as polyurethanes, epoxy resins, and ion-exchange membranes via tailored catalytic processes, and (3) copolymerization/blending with biopolymers to enhance material properties. Breakthroughs in catalysts (enzymes, ionic liquids), solvent-free systems, and energy-efficient reactors are highlighted for improving the reaction selectivity and scalability. Despite progress, challenges persist in managing mixed plastic wastes, removing contaminants, and achieving cost parity with virgin polymers. Emerging trends, including enzymatic engineering and AI-guided monomer-to-polymer design, are proposed to address these barriers. By bridging molecular innovation with industrial feasibility, PET upcycling offers dual environmental and economic incentives to close the plastic lifecycle loop.