Chinese Journal of Polymer Science最新文献

The deformation mechanism of glycerol plasticized poly(vinyl alcohol) (PVA) with different hydrolyses (88%, 92%, 98%) at elevated temperatures (60–100 °C) was elucidated by in situ synchrotron radiation X-ray scattering. The vinyl acetate (VAc) in PVA acts as a non-crystalline chain defect, which significantly influences the plastic deformation and stretching-induced crystallization behavior of PVA. The key microstructural parameters of PVA during deformation, such as crystallinity (χ_c), lateral crystallite size (L), and long period (l), in combination with the stress-strain curves, were obtained. The experimental results show that the deformation process of the plasticized PVA film present a three-stage evolution: (i) a plastic deformation zone. The plastic deformation of the crystallite occurs as evidenced by the apparent decrease in crystallinity and lamellar reorientation induced by stretching; (ii) the stress softening zone. The decreasing trend of crystallinity becomes slow, and the long period becomes smaller, which indicates that PVA crystallization is induced by stretching; and (iii) the strain-hardening zone. There is a synergistic effect between the crystallite destruction and formation. Further research reveals that a high temperature and low degree of alcoholysis favor the stretching-induced crystallization of PVA, while the system with a high degree of alcoholysis shows significant characteristics of preferred crystal growth.

Integrated conductive elastomers with excellent mechanical performance, stable high conductivity, self-healing capabilities, and high transparency are critical for advancing wearable devices. Nevertheless, achieving an optimal balance among these properties remains a significant challenge. Herein, through in situ free-radical copolymerization of 2-[2-(2-methoxyethoxy)ethoxy]ethyl acrylate (TEEA) and vinylimidazole (VI) in the presence of polyethylene glycol (PEG; M_n=400), tough P(TEEA-co-VI)/PEG elastomers with multiple functionalities were prepared, in which P(TEEA-co-VI) was dynamically cross-linked by imidazole-Zn²⁺ metal coordination crosslinks, and physically blended with PEG as polymer electrolyte to form a homogeneous mixture. Notably, Zn²⁺ has a negligible impact on the polymerization process, allowing for the in situ formation of numerous imidazole-Zn²⁺ metal coordination crosslinks, which can effectively dissipate energy upon stretching to largely reinforce the elastomers. The obtained P(TEEA-co-VI)/PEG elastomers exhibited a high toughness of 10.0 MJ·m^-3 with a high tensile strength of 3.3 MPa and a large elongation at break of 645%, along with outstanding self-healing capabilities due to the dynamic coordination crosslinks. Moreover, because of the miscibility of PEG with PTEEA copolymer matrix, and Li⁺ can form weak coordination interactions with the ethoxy (EO) units in PEG and PTEEA, acting as a bridge to integrate PEG into the elastomer network. The resulted P(TEEA-co-VI)/PEG elastomers showed high transparency (92%) and stable high conductivity of 1.09×10^-4 S·cm^-1. In summary, the obtained elastomers exhibited a well-balanced combination of high toughness, high ionic conductivity, excellent self-healing capabilities, and high transparency, making them promising for applications in flexible strain sensors.

Poly(vinyl alcohol) (PVA) is a biodegradable and environmentally friendly material known for its gas barrier characteristics and solvent resistance. However, its flammability and water sensitivity limit its application in specialized fields. In this study, phytic acid (PA) was introduced as a halogen-free flame retardant and biochar (BC) was introduced as a reinforcement to achieve both flame resistance and mechanical robustness. We thoroughly investigated the effects of BC particle sizes (100–3000 mesh) and addition amounts (0 wt%–10 wt%), as well as PA addition amounts (0 wt%–15 wt%), on the properties of PVA composite films. Notably, the PA10/1000BC5 composite containing 10 wt% PA and 5 wt% 1000 mesh BC exhibited optimal properties. The limiting oxygen index increased to 39.2%, and the UL-94 test achieved a V-0 rating. Additionally, the PA10/1000BC5 composite film demonstrated significantly enhanced water resistance, with a swelling ratio reaching 800% without dissolving, unlike that of the control PVA. The water contact angle was 70°, indicating that hydrophilic properties remained essentially unaffected. Most importantly, the tensile modulus and elongation at break were 213 MPa and 281.7%, respectively, nearly double those of the PVA/PA composite film. This study presents an efficient and straightforward method for preparing PVA composite films that are flame-retardant, tough, and waterresistant, expanding their potential applications in various fields.

High-entropy polymer blends composed of polypropylene (PP), polystyrene (PS), polyamide 6 (PA6), poly(lactic acid) (PLA), and styrene-ethylene-butylene-styrene (SEBS) were successfully fabricated using maleic anhydride-grafted SEBS (SEBS-g-MAH) as a compatibilizer. Dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and mechanical testing demonstrated that SEBS-g-MAH significantly enhanced the compatibility between the polar (PA6, PLA) and nonpolar (PP, PS, SEBS) components. The compatibilizer effectively refined the microstructure, substantially reduced the domain sizes, and blurred the phase boundaries, indicating enhanced interfacial interactions among all the components. The optimal compatibilizer content (15 wt%) notably increased tensile ductility (elongation at break from 5.0% to 23.7%) while maintaining balanced crystallization behavior, despite slightly decreasing modulus. This work not only demonstrates the broad applicability of high-entropy polymer blends as a sustainable strategy for converting complex, unsorted plastic waste into high-performance value-added materials that significantly contribute to plastic upcycling efforts, but also highlights intriguing physical phenomena emerging from such complex polymer systems.

Exploration of new green polymerization strategies for the construction of conjugated polymers is important but challengeable. In this work, a multicomponent polymerization of acetylarenes, alkynones and ammonium acetate for in situ construction of conjugated poly(triarylpyridine)s was developed. The polymerization reactions of diacetylarenes, aromatic dialkynones and NH₄OAc were performed in dimethylsulfoxide (DMSO) under heating in the presence of potassium tert-butoxide (t-BuOK), affording four conjugated poly(2,4,6-triarylpyridine)s (PTAPs) in satisfactory yields. The resulting PTAPs have good solubility in common organic solvents and high thermal stability with 5% weight loss temperatures reaching up to 460 °C. They are also electrochemically active. The PTAPs incorporating tetraphenylethene units manifest aggregation-induced emission features. Moreover, through simply being doped into poly(vinyl alcohol) (PVA) matrix, the polymer and model compound containing triphenylamine moieties exhibit room-temperature phosphorescence properties with ultralong lifetimes up to 696.2 ms and high quantum yields up to 28.7%. This work not only provides a facile green synthetic route for conjugated polymers but also offers new insights into the design of advanced materials with unique photophysical properties.

High mortality of choroidal melanoma (CM) is mainly attributed to the high likelihood of tumorous recurrence. The essential challenge lies in the presence of residual CM cells survived from the antitumor treatment. These residual tumorous cells are most likely to cause tumorous recurrence. This article reports the preparation of a multifunctional nanocomposite which can be used to treat CM efficiently via a chemotherapyassisted- photothermal therapy (CTH-PTT). The nanocomposite comprises of alpha-tocopheryl succinate (α-TOS) and carboxylic chitosan modified graphene (CG). α-TOS has been potentially seen as an efficient CTH antitumor drug while its deficiency such as easy being hydrolyzed by gastrointestinal esterase and poor hydrophilicity inevitable limits the clinic application of α-TOS. CG is introduced to overcome these shortcomings, offering additional advantages such as the PTT possibility for the antitumor application. The employment of CG-α-TOS on ocular CM cells caused more than 80% inhibition rates after irradiation under an 808 nm laser for 10 min. The outcomes of this work provide a facile and advantageous way to resolve the essential issue of the treatment of ocular tumors such as CM.

To retain its inherent biodegradability, simultaneously improving the strength and toughness of poly(lactic acid) (PLA) is a significant challenge. In this study, we propose an innovative multiple dynamic pressure (MDP) process that can produce pure PLA with excellent mechanical properties. The MDP process generates a dynamic stretching effect by regulating the application and release of pressure, prompting disordered molecular chains to be arranged regularly along the direction of the dynamic force field. This promoted the formation of more ordered crystal forms (α-form) and strengthened the connection between the crystalline and amorphous regions. Results show that after MDP treatment, the tensile strength and strain at break of MDP-PLA are significantly improved, reaching 91.6 MPa and 80.1% respectively, which are 49.4% higher and 10 times higher than those of the samples before treatment. The mechanical properties of MDP-PLA can be regulated as needed by adjusting the cycle times and peak pressure. In addition, through a systematic study of the structural evolution of MDP-PLA, the performance regulation mechanism of the MDP process was thoroughly investigated, and the internal relationship among the process-structure-performance was clarified. This research not only opens a new technical path for the preparation of high-performance pure PLA but also provides important guidance for the high-performance modification of other semi-crystalline polymers, thus possessing significant scientific and engineering value.

Machine learning (ML) has emerged as a powerful tool for predicting polymer properties, including glass transition temperature (T_g), which is a critical factor influencing polymer applications. In this study, a dataset of polymer structures and their T_g values were created and represented as adjacency matrices based on molecular graph theory. Four key structural descriptors, flexibility, side chain occupancy length, polarity, and hydrogen bonding capacity, were extracted and used as inputs for ML models: Extra Trees (ET), Random Forest (RF), Gaussian Process Regression (GPR), and Gradient Boosting (GB). Among these, ET and GPR achieved the highest predictive performance, with R² values of 0.97, and mean absolute errors (MAE) of approximately 7–7.5 K. The use of these extracted features significantly improved the prediction accuracy compared to previous studies. Feature importance analysis revealed that flexibility had the strongest influence on T_g, followed by side-chain occupancy length, hydrogen bonding, and polarity. This work demonstrates the potential of data-driven approaches in polymer science, providing a fast and reliable method for T_g prediction that does not require experimental inputs.

This paper presents a polymer-brush-guided templating strategy for fabricating ordered gold plasmonic architectures. The synthesized nanostructures featuring densely packed Au nanoparticles (NPs) exhibited strong surface-enhanced Raman scattering (SERS) activity. Using a simple mechanical transfer technique, these assemblies were integrated into flexible polydimethylsiloxane (PDMS) films. Polymer encapsulation during synthesis ensures structural integrity during processing, resulting in a mechanically robust SERS substrate with exceptional analytical performance. This platform achieved 4-mercaptobenzoic acid (4-MBA) detection at 100 pmol/L (10^-10 mol/L) with high reproducibility (RSD=6.8%). Environmental and mechanical stability tests demonstrated 95% signal retention over 30 days and sustained functionality after 100 bending/twisting cycles. Combined with a non-destructive adhesion-transfer protocol, the substrate enabled on-site thiram detection on apple surfaces (1 μmol/L limit). This study provides a scalable approach for developing flexible SERS devices for food safety monitoring and environmental analysis.

It is important to understand the evolution of the matter on the polymer membrane surface. The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation. Herein, an aggregation-induced emission (AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster (CD@Glucose) and a tetraphenylethylene derivative modified with boronic acid groups (TPEDB) on the surface of a polyacrylonitrile (PAN) ultrafiltration membrane. This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane. With the increase in the number of polymer layers, the separation and antifouling properties of the membrane gradually improved. Owing to the AIE property of the crosslinking agent TPEDB, the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity. With the aggravation of membrane fouling, the fluorescence decreased gradually, but recovered after cleaning. Therefore, this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.