Macromolecular Chemistry and Physics最新文献

Unlike dense bulk materials, the hollow structure of foam materials brings additional functionality and applications. Benefiting from the excellent biocompatibility of polyurethane, polyurethane foams have found numerous applications in the biomedical field. In terms of mechanical properties, beyond the selection of molecular structure, the performance of polyurethane foams can be effectively regulated by the pore structure. Functionally, in addition to achieving in vivo degradation, shape memory, and mechanical support like bulk polyurethane, the hollow pore structure enables critical capabilities such as exudate absorption and drug loading. Moreover, when used as a scaffold, the hollow structure is conducive to cell proliferation, growth, and migration, thereby facilitating tissue growth and repair. However, given the toxicity concerns associated with traditional isocyanates, non-isocyanate polyurethane foams (NIPUFs) are emerging as a crucial direction for the next generation of safer biomaterials. This review mainly summarizes the recent developments of thermoplastic polyurethane foams in the fields of dressings, scaffolds, embolization, and drug delivery. Significantly, it highlights the unique biomedical advantages of NIPUFs, outlining their preparation methods and preliminary applications as a promising alternative to conventional polyurethanes, with potential benefits in terms of improved sustainability and reduced carbon footprint.

In free radical ring-opening copolymerization of cyclic ketene acetals (CKA) with vinyl monomers, a major challenge is the often-low reactivity of CKAs and thus insufficient ester incorporation and homogeneity. Most workarounds, like semibatch copolymerization, require a considerable change in the system. In this work, we report a method to improve ester incorporation into the backbone and homogeneity of the polymer by using a batch copolymerization in 1,4-dioxane above solvent boiling point. The monomer system of 2-methylene-4-phenyl-1,3-dioxolane (MPDL) and syringyl methacrylate (SM) showed improved copolymerization parameters (r_MPDL = 0.032 and r_SM = 2.464) compared to the polymers obtained at 70°C in anisole. Basic hydrolysis with potassium hydroxide (KOH) in tetrahydrofuran (THF)/methanol (MeOH) was conducted to study structural homogeneity and was compared with semibatch experiments.

Electrically conductive polymers are a groundbreaking class of materials commonly utilized in medical research focused on healthcare devices such as biosensors. They share the mechanical properties of a classical polymer as well as the electronic properties of metals. This allows them to function as flexible, lightweight, and highly efficient components in both wearable and implantable sensor technologies. Although research has shown promising findings, most of the polymer sensors presented are only partially or not at all biologically compatible with the human body. This work demonstrates a new electroconductive polymer matrix composed of bio-based materials–bovine gelatin, whey protein isolate (WPI), polyaniline (PANI), and phytic acid (PA)– as a soft, compliant material. The results showed a homogeneous and well-integrated matrix that remains stable up to $��{115}^{\circ }�C�$. The water content in the samples ranged from 29.99% to 63.81%, depending on the method of preparation. The electromechanical properties before and after self-healing were also investigated, along with antibacterial properties against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. This study developed a new formulation of a conductive polymer matrix that is potentially biocompatible, yet still exhibits satisfactory mechanical properties like its predecessors, making it a candidate for bio-sensing applications.

Compared with conventional polyurethanes, non-isocyanate polyurethanes (NIPUs) prepared via the polyaddition of bis(cyclic carbonates) and diamines have attracted considerable attention due to their avoidance of highly toxic precursors such as isocyanates and phosgene. However, the limited availability of bis(cyclic carbonates) has hindered the further industrialization of NIPUs. Therefore, we proposed a strategy for preparing NIPU using commercial biobased isoprene as starting material. As a proof of concept, A three-step synthetic route was developed to convert isoprene into a series of bis(cyclic carbonates) via epoxidation, CO₂ cycloaddition, and thiol–ene click reactions. Subsequently, the designed cyclic carbonate monomers were copolymerized with four different diamine monomers to synthesize NIPUs. The molecular weight (M_n = 6.0∼24.0 kDa) and thermal properties (T_g = 1.4∼34.8°C) of the resulting NIPU could be tailored through regulating the structure of monomers. Additionally, the produced NIPU was applied as adhesive showed an adhesion strength up to 1.87 MPa on stainless steel substrates. The proposed strategy not only broadens the monomer sources of NIPUs but also effectively increases their biocarbon content.

Conductive hydrogels demonstrate broad prospects in the field of wearable strain sensors due to their good flexibility, electrical conductivity, and biocompatibility. However, the complexity of practical application environments imposes higher requirements on the comprehensive properties of such materials, including electrical conductivity, mechanical strength, self-healing, and adhesion. To address this, this study introduces the conductive polymer polyaniline (PANI) into a sodium polyacrylate (PAAS) hydrogel matrix, successfully constructing a PAAS/PANI conductive hydrogel with a dual chemically cross-linked network via a one-pot method. Experimental results indicate that the incorporation of PANI not only effectively enhances the electrical conductivity of the hydrogel but also improves its mechanical properties. When the PANI content reaches 7.5 wt%, the hydrogel exhibits good overall performance: its tensile strength reaches 314 kPa, the elongation at break reaches 872%, and the electrical conductivity reaches 2.46 S m⁻¹. In terms of sensing performance, the material also demonstrates outstanding characteristics: under 600% tensile strain, its gauge factor (GF) reaches 4.52, along with negligible hysteresis and rapid response and recovery speeds. Additionally, the PAAS/PANI hydrogel possesses good thermal stability, self-healing properties, adhesion, and biocompatibility. Based on this hydrogel, the constructed wearable strain sensor can accurately, stably, and real-time monitor various human joint movements.

This study reports a novel adsorbent prepared via a Pickering emulsion-template method for the efficient adsorption of Ce(III) from aqueous solutions. Water-in-oil Pickering emulsions were first stabilized by commercial nano-SiO2, using an aqueous sodium alginate solution as the dispersed phase and kerosene-diluted di-(2-ethylhexyl) phosphate (P204) as the continuous phase. The emulsion droplets were then gelled in a Ca²⁺ solution to form stable Pickering emulsion hydrogel beads (PEHG), thereby encapsulating the P204-containing organic phase within a calcium alginate matrix. Fourier transform infrared spectroscopy and scanning electron microscopy confirmed the successful encapsulation and the structural integrity of the PEHG. Batch adsorption experiments demonstrated that the adsorption kinetics followed a pseudo-second-order model, indicative of chemisorption, while the equilibrium data were best described by the Redlich-Peterson isotherm, suggesting a complex adsorption mechanism involving both monolayer and multilayer interactions. Remarkably, the PEHG retained a Ce(III) removal efficiency above 99% over five consecutive adsorption-desorption cycles, with no observable structural degradation or leakage of the encapsulated phase. This strategy of encapsulating the functional organic phase (P204) within a hydrogel matrix not only enhances its utilization efficiency but also effectively prevents its leakage into the aqueous environment, offering a promising and sustainable approach for rare earth element recovery.