Chinese Journal of Polymer Science最新文献

The use of biomass feedstocks for the manufacture of high-performance polymers can help expand their range of applications and reduce their dependence on finite fossil resources. However, improving the heat resistance and hydrophilicity of bio-based polyesters remains a significant challenge. Herein, we introduce N,N′-trans-1,4-cyclohexane-bis(pyrrolidone-4-methylcarboxylate) (CBPC), a novel bio-based tricyclic dibasic ester synthesized from renewable dimethyl itaconic acid and trans-1,4-cyclohexane diamine via an aza-Michael addition reaction. As a unique comonomer, CBPC features a rigid tricyclic backbone that significantly enhances chain packing and thermal stability, whereas its pyrrolidone side groups impart tunable polarity and improved hydrophilicity. Using CBPC, diphenyl carbonate, and 1,4-butylene glycol, a series of PBCC copolymers with 10 mol%–30 mol% CBPC was synthesized via ester-exchange and melt polycondensation methods. Incorporation of CBPC raised the melting temperature (T_m) from 56.8 °C to 225.8 °C and the initial decomposition temperature (T_d5%) from 258.0 °C to 306.7 °C, positioning PBCC among the most heat-resistant bio-based polyesters reported. Additionally, the pyrrolidone units enabled transformation from hydrophobic to hydrophilic. This study demonstrates that CBPC is an effective and innovative building block for the design of bio-based polymers with enhanced thermal and surface properties, offering a promising strategy for the development of high-performance sustainable materials.

The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability. However, conventional polypeptide synthesis from the polymerization of N-carboxyanhydride (NCA) is conducted at relatively slow rates, requiring long tubing or ending up with low-molecular-weight polymers. Inspired by recent advances in accelerated NCA polymerization, we report the crown-ether-catalyzed, rapid synthesis of polypeptide materials in cosolvents in flow reactors. The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min, yielding well-defined polypeptides (up to 30 kDa) through a 20-cm tubing reactor. Additionally, random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer. We believe that this work highlights the accelerated polymerization design in flow polymerization processes, offering the continuous production of polypeptide materials.

In this study, a novel linear polyimide chain (PTCDA-DCH) was used as an electrochemiluminescence (ECL) emitter, employing a chiral metal-organic framework (MOF) (Zn-Dcam-dabco) as the chiral selector and ferrocene (Fc) as a quencher to construct a chiral sensor for detecting histidine (His) enantiomers. Competitive interactions between Fc and His induce partial Fc desorption from the sensor surface, leading to ECL signal recovery. Differential Fc release due to the distinct binding affinities of Zn-Dcam-dabco for His enantiomers enabled precise chiral discrimination. Notably, the sensor achieved the quantitative detection of His enantiomers with an limits of detection (LOD) of 8 µmol/L. Furthermore, the sensor demonstrated excellent recovery rates of 98.0%–104% for l-histidine (L-His) and 92.0%–95.9% for D-His in spiked milk samples, validating its reliability for real-sample analysis. This study provides a promising platform for ECL-based chiral recognition, bioanalysis, and the rapid assessment of amino acids in food products.

Single-step ethylene polymerization over a binary catalyst, including zirconocene precatalysts of various designs, has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene (UHMWPE) and low-molecular-weight HDPE (LMWPE) directly in synthesis. Zirconocenes rac-(CH₃)₂SiInd₂ ZrCl₂ (Zr-1) and rac-(C₆H₁₀)CpIndZrCl₂ (Zr-2) activated with methylaluminoxane (MAO) were used as the components of the binary catalyst. It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30 °C leads to the production of UHMWPE with M_w=1000 kg·mol^-1 and LMWPE with M_w=18 kg·mol^-1, respectively. Reactor polymer compositions (RPC) with LMWPE fraction contents ranging from 9 wt% to 42 wt% were obtained when a molar fraction of Zr-2 in the binary catalyst (Zr-1+Zr-2)/MAO varied in the range from 0.3 to 0.85. A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution (MWD) and includes UHMWPE (M_w=1000 kg·mol^-1) and LMWPE (M_w=18 kg·mol^-1) fractions. The degree of crystallinity of the polymer products was determined using the DSC method. The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition. UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.

Conductive hydrogels derived from natural polymers have attracted increasing attention in wearable electronics due to their inherent biocompatibility and sustainability. However, their poor mechanical strength, limited conductivity and unsatisfactory environmental adaptability remain significant challenges for practical applications. In this study, we report a high-performance gelatin-based conductive hydrogel (GPC) reinforced with polypyrrole-decorated cellulose nanofibers (PPy@CNF) and enhanced by a zwitterionic betaine/(NH₄)₂SO₄ solution. The PPy@CNF hybrid nanofillers were synthesized via in situ oxidative polymerization, enabling homogeneous dispersion of PPy along the CNF surface. The incorporation of PPy@CNF significantly improved both mechanical strength and conductivity of the gelatin hydrogel. Meanwhile, the Hofmeister effect induced by (NH₄)₂SO₄ strengthened the hydrogel network, and the introduction of betaine further enhanced its anti-freezing and moisture-retention properties. The optimized GPC hydrogel exhibited a high tensile strength of 1.02 MPa, conductivity of 1.5 S·m^-1, and stable performance at temperatures down to -50 °C. Furthermore, it was successfully assembled into a wearable strain sensor for real-time human motion monitoring, and as an electrode layer in a flexible triboelectric nanogenerator (TENG), enabling biomechanical energy harvesting and self-powered sensing. This work provides a promising strategy for developing sustainable, multifunctional hydrogels for next-generation wearable electronics.

Silibinin, a natural flavanone extracted from the milk thistle plant (Silybum marianum), has been shown to have various therapeutic applications, including liver protection, antioxidant, anticancer, anti-inflammatory, and many other effects. However, silibinin exhibits poor oral absorbance and low bioavailability owing to its limited water solubility, which limits its therapeutic efficiency and further clinical translation. To address these issues, we propose an antioxidant glycopolypeptide micelle strategy to target the delivery of silibinin to enhance its solubility, bioavailability, and antioxidant activity. This versatile micelle self-assembled from a glycopolypeptide, N-acetylgalactosamine-grafted poly(glutamic acid)-block-poly(tyrosine). N-acetylgalactosamine (GalNAc) is incorporated to enable liver targeting by selectively binding to the asialoglycoprotein receptor, which is overexpressed on hepatocellular carcinoma cells. The antioxidant polypeptide polytyrosine, as well as encapsulated silibinin, exhibits a synergistic reactive oxygen species (ROS) scavenging effect. The obtained results confirmed that silibinin can be effectively encapsulated into the glycopolypeptide micelles through self-assembly, achieving a loading efficiency and loading content of 96.6% and 42.9%, respectively. The silibinin-loaded glycopolypeptide micelles exhibited enhanced cellular uptake and a synergistic ROS scavenging effect in hepatocellular carcinoma cells. Overall, these antioxidant glycopolypeptide micelles hold promise as safe and efficient drug delivery systems for targeting hepatocellular carcinoma cells, potentially providing an effective strategy to enhance the bioavailability and antioxidant activity of silibinin.

In this study, dynamic selenonium salts were incorporated into a polyurethane (PU) matrix to develop transparent, healable and antibacterial coatings. Through systematic formulation optimization, optically clear materials with excellent room-temperature hardness were obtained. Fine-tuning the selenonium content established a synergy between antibacterial performance and network dynamics, as evidenced by vitrimer-like rheological behavior at elevated temperatures. Consequently, the coatings exhibited outstanding reprocessability while maintaining high transparency and structural stability after prolonged saltwater exposure. These integrated features underscore the potential of the developed cationic PU coatings as robust, multifunctional materials for electronic device protection and marine antifouling, combining long-term transparency, recyclability, and antibacterial durability.

Shear banding in entangled polymer melts remains a fundamental yet unresolved phenomenon in nonlinear polymer rheology. Here, we perform molecular dynamics simulations of bidisperse entangled melts—comprising equal numbers of chains with lengths N=200 and N=400—to uncover the structural origins and dynamic evolution of shear banding. This bidisperse system amplifies spatial heterogeneities in the entanglement network and facilitates direct comparison with monodisperse melts of N=300, revealing quantitatively consistent steady-state shear stress versus shear rate responses. Notably, a pronounced stress plateau spanning over an order of magnitude in shear rate is observed, within which shear banding emerges reproducibly across independent simulations, as confirmed by systematic velocity profile and interface position analyses. Our findings challenge the prevailing notion that shear banding arises solely from dynamic flow instabilities. Instead, we establish a microstructure-driven framework, demonstrating that shear band nucleation is governed by pre-existing structural heterogeneities—specifically, localized weakening of the entanglement network at short-chain-enriched “soft spots”, indicative of a robust microstructural memory effect. During shear start-up, short chains preferentially disentangle and migrate along the shear direction; beyond a critical strain, long chains retract and redistribute away from the fast shear band center to minimize elastic energy. This chain-length-dependent migration dynamically enriches the shear band in short chains, stabilizing its structure and revealing a molecular mechanism that links entanglement heterogeneity to macroscopic flow localization. By bridging molecular-scale structural features with nonlinear rheological responses, this work offers a complementary perspective to classical tube and convective constraint release (CCR) models, highlighting the critical interplay between microstructural heterogeneity and chain migration in the onset and persistence of shear banding.

Temperature-sensitive random copolymerized nanohydrogels were prepared via a one-pot polymerization method using N-isopropylacrylamide (NIPAM) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as raw materials. Transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) analyses revealed the partially crystallized porous nanostructure of the gels, which is consistent with the characteristics of porous nanohydrogel materials. The low-molecular-weight polymers exhibited enhancement and sharpening of the end group peaks in Fourier-transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance hydrogen (¹H-NMR) spectra due to the high proportion of small molecules or low-molecular-weight chain segments. In turn, the high-molecular-weight polymers showed pronounced peaks in the main chain segments because of the long-chain effect. Hygroscopicity increased with the molecular weight of the selected polymers, but was inhibited by temperatures below the lower critical solution temperature (LCST). Meanwhile, moisture desorption was faster in low-molecular-weight samples, and the overall moisture desorption rate rose above the LCST value. According to the kinetic analysis, the moisture absorption process conformed to the quasi-primary or quasi-secondary kinetic model, whereas the moisture desorption followed the quasi-secondary model. Moisture cycling experiments showed that the material maintained stable moisture absorption and desorption performance after several cycles, which is essential for long-term cycling.

4D-printable shape memory polymers (SMPs) hold great promise for fabricating shape morphing biomedical devices, but most existing printed polymers either require harsh activation conditions or lack sufficient mechanical strength for vascular implantation. Here, we report a dual-stimuli-responsive shape memory polymer system enhanced by acrylated Pluronic F127 (PF127-DA) micelles, which can be fabricated using digital light processing (DLP) based 3D printing. The PF127-DA based nanoscale micelles, which are formed via self-assembly in the hydrogel ink for 3D printing, act as crosslinkers to improve mechanical strength, fatigue resistance and elastic recovery. After drying the printed hydrogel, the obtained SMPs exhibit excellent shape recovery behaviour under mild physiological conditions—specifically body temperature (37 °C) and aqueous swelling—resulting in recovery stress up to about 150 kPa. This swelling-assisted actuation enables effective radial support, making the printed constructs suitable for vascular use. In vitro cytocompatibility assays with NIH/3T3 fibroblasts confirmed the suitable biocompatibility. Furthermore, the self-expanding behavior of the printed stents was validated in an occluded vessel model under physiological conditions. These results demonstrate the feasibility of 4D printed micelle-enhanced SMP for patient-specific, minimally invasive vascular stents and other soft implantable devices requiring high recovery force under physiological stimulation.