Macromolecular Chemistry and Physics最新文献

The application of enzymes in biocatalytic and biomedical technologies remains challenging due to their intrinsic instability, despite evidence that immobilization on solid supports enhances stability and reusability. Herein, we report a simple strategy for covalent immobilization of urease, an enzyme with inherently poor stability at ambient temperature, onto silica nanoparticle surfaces grafted with poly(acrylic acid) (pAA-g-SiNPs) via reversible addition-fragmentation chain transfer polymerization. The resulting hybrid materials offer a high density of surface carboxyl functionalities enabling efficient urease conjugation, yielding a stable biocatalytic material (pAA-g-SiNPs/U). Kinetic studies of urea hydrolysis confirmed that immobilized urease retained catalytic activity for nearly one month under ambient conditions, in contrast to free urease, which losses catalytic activity within 2–5 days when stored in ambient temperature. Moreover, pAA-g-SiNPs/U exhibited excellent operational stability, maintaining activity after multiple catalytic cycles and under alkaline pH and elevated temperatures up to 60 °C. This enhanced performance proves the ability of the hybrid polymer-silica platform to mitigate enzymatic denaturation while extending functional shelf-life. Our approach offers a simple and versatile route for preserving enzymes at room temperature, thereby facilitating their translation into biomedical applications and enabling their use as recyclable heterogeneous biocatalysts.

Difluoroamino (–NF₂) is one of the ideal energetic functional groups for enhancing the overall performance of solid propellants. Its strong oxidizing properties reduce the average molecular weight of combustion products and increase the specific volume of combustion gases, thereby significantly boosting the energy release level of solid propellants and demonstrating tremendous application potential. In this study, hydroxyl-terminated polyether (HTPE) was copolymerized with 3-difluoroaminomethyl-3-methyloxetane (DFAMO) via cationic ring-opening copolymerization to form the PDFAMO-HTPE-PDFAMO triblock copolymer, which achieves coordinated optimization of energy and mechanical properties. PDFAMO-HTPE-PDFAMO retains the benefits of HTPE's low glass transition temperature and favorable thermal stability, with a peak decomposition temperature of 257.1°C and a corresponding decomposition enthalpy of 1385.64 J/g. Combined with three model-free kinetic calculation methods to obtain key thermal performance parameters such as activation energy and frequency factor. Furthermore, TG-FTIR technology was utilized to validate the thermal decomposition process and elucidate the decomposition mechanism, which is divided into a two-stage pyrolysis process: initial decomposition of the difluoroamino groups followed by scission of the polymer backbone. These results demonstrate the potential of PDFAMO-HTPE-PDFAMO tri-block copolymer as the energetic propellant binder.

This Perspective provides an overview of the fundamental concepts regarding polymeric delivery of DNA-encoded biologics for the durable expression of biologics such as monoclonal antibodies (mAbs), endogenous proteins, and peptides. The concept of vectorizing proteins from the delivery of engineered plasmid DNA (pDNA) has long been considered to treat a range of infectious diseases, oncology, metabolic, and autoimmune disorders. However, viral vectors are non-redosable and often immunogenic, and lipid nanoparticles face challenges associated with stability, burst release, and toxicity. By contract, polymer nanoparticles (PNPs) with ionizable amine moieties can readily self-assemble with encoding pDNA and deliver high doses of cargo. We describe this concept within the rapid growth of therapeutic mAbs as a clinical modality. Specifically, PNP design considerations are outlined using conventional principles from gene therapy, protein engineering, and controlled drug delivery. This convergent approach, which we are pursuing with data-driven materials discovery and an Artificial Intelligence (AI) enabled platform, creates promising new classes of potent biologics to be developed at scale. The breadth of possible programmable proteins from encoded DNA ranges from specialized mAbs that treat HIV to important anti-obesity peptides, representing exciting avenues for polymer scientists to make important contributions to the next generation of genetic medicines.

In this study, we prepared a PPC-SA with high water vapor barrier properties. A new catalyst system was designed for highly efficient terpolymerization of propylene oxide (PO), carbon dioxide, and succinic anhydride (SA). Using aluminum alkoxide as a co-catalyst and combining it with zinc glutarate to form a composite catalyst, the yield of the ternary copolymer was successfully increased from 51.4 to 147.8 g_polymer/g_cat., representing a threefold improvement. The number-average molecular weight of the resulting polymer was determined to be 10.5 × 10⁴ g/mol using gel permeation chromatography (GPC). The thermal and mechanical properties, as well as the water vapor permeability of the ternary copolymer, were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile testing, and water vapor transmittance testing. This work guides the design of catalysts for CO₂ copolymerization and the utilization of CO₂ to produce new carbon dioxide-based plastics.

In this study, Gel Polymer Electrolytes (GPEs) based on pectin were prepared using solution casting at different weight percentages (3–6 wt.%) to investigate their effect on the ionic conductivity and performance of Dye-Sensitized Solar Cells (DSSCs). Fourier-transform infrared spectroscopy (FTIR) revealed a shift in pectin's O─H functional group, indicating the ion-cation interactions between the Ionic-Liquid and PEs, which promotes the flow of free ions through the electrolytes. The ionic conductivity GPE with the addition of 5 wt.% pectin exhibited an optimum value of 2.04 × 10⁻³ S cm⁻¹, which corresponded to an achieved efficiency of 6.22%. These optimal values highlight the potential of these materials for advancing renewable energy technologies. The results of electrochemical impedance spectroscopy (EIS) indicate improved charge transport, further supporting the idea that this enhancement is driven by greater ionic conductivity and electron mobility through pathways formed by interactions between polymer-bound ions and cations.

Bio-derivable, non-isocyanate polyurethanes (NIPUs) offer a potentially safer, more sustainable alternative to isocyanate-based polyurethanes (PUs), though structure–property comparisons are needed to confirm their high-performance. Herein, PUs and NIPUs are synthesized from petroleum-derived bisphenol A (BPA) and lignin-derivable bisguaiacol A (BGA) to elucidate how pendent methoxy (from BGA) and hydroxyl groups (from NIPU chemistry) govern hydrogen bonding, free-volume effects, and polymer properties. Fourier-transform infrared spectroscopy shows increased hydrogen bonding of ─OH/─NH groups in BGA-based systems (BPA-PU: 90%, BGA-PU: 97%, BPA-NIPU: 75%, BGA-NIPU: 89%) and more ordered C═O hydrogen bonding (BPA-NIPU: 3% vs. BGA-NIPU: 26%). NIPUs exhibit ∼8°C higher glass transition temperatures, suggesting hydrogen-bond-mediated chain mobility. Mechanical tests reveal a strength–elongation tradeoff: BPA-PU achieves the highest modulus (2.7 GPa) and strength (∼59 MPa), while BGA-NIPU shows the greatest elongation (∼95%) and highest toughness (∼7 MJ m⁻³). Rheology indicates that methoxy and hydroxyl groups slow relaxation, though only methoxy groups reduce dynamic fragility. Contact angle measurements confirm methoxy groups increase hydrophobicity and lower surface energy (<30 mN m⁻¹), enabling potential adhesion to low-surface-energy substrates. Overall, strategic lignin-derivable monomer design and NIPU chemistry yield sustainable thermoplastics with tunable thermomechanical, rheological, and interfacial properties, highlighting their promise as easily-processable, high-performance materials.

Bio-derivable, non-isocyanate polyurethanes (NIPUs) offer a potentially safer, more sustainable alternative to isocyanate-based polyurethanes (PUs), though structure–property comparisons are needed to confirm their high-performance. Herein, PUs and NIPUs are synthesized from petroleum-derived bisphenol A (BPA) and lignin-derivable bisguaiacol A (BGA) to elucidate how pendent methoxy (from BGA) and hydroxyl groups (from NIPU chemistry) govern hydrogen bonding, free-volume effects, and polymer properties. Fourier-transform infrared spectroscopy shows increased hydrogen bonding of ─OH/─NH groups in BGA-based systems (BPA-PU: 90%, BGA-PU: 97%, BPA-NIPU: 75%, BGA-NIPU: 89%) and more ordered C═O hydrogen bonding (BPA-NIPU: 3% vs. BGA-NIPU: 26%). NIPUs exhibit ∼8°C higher glass transition temperatures, suggesting hydrogen-bond-mediated chain mobility. Mechanical tests reveal a strength–elongation tradeoff: BPA-PU achieves the highest modulus (2.7 GPa) and strength (∼59 MPa), while BGA-NIPU shows the greatest elongation (∼95%) and highest toughness (∼7 MJ m⁻³). Rheology indicates that methoxy and hydroxyl groups slow relaxation, though only methoxy groups reduce dynamic fragility. Contact angle measurements confirm methoxy groups increase hydrophobicity and lower surface energy (<30 mN m⁻¹), enabling potential adhesion to low-surface-energy substrates. Overall, strategic lignin-derivable monomer design and NIPU chemistry yield sustainable thermoplastics with tunable thermomechanical, rheological, and interfacial properties, highlighting their promise as easily-processable, high-performance materials.