Journal of Polymer Science Part A: Polymer Chemistry最新文献

Herein, the six-membered sulfur-containing cyclic carbonates was successfully synthesized from d- and l-xylose through an environmental friendly process by employing carbonyl sulfide (COS) as a sustainable C1-carbonation agent. The ring-opening polymerization of the monomers were rapidly initiated by bifunctional organocatalysts and alkali metal alkoxides, respectively, under ambient reaction conditions. The resultant sulfur-containing polycarbonates exhibit high-temperature resistance and good optical properties. This work furnishes an original and practical strategy for utilizing COS as a sulfur feedstock in biopolymer synthesis.

A spin-spray-assisted layer-by-layer assembly platform was developed by Dr Li and colleagues to fabricate polymer films with self-healing, UV-protection, and anti-fog properties. This method was found to be more efficient and a time-saver in making a homogeneous thick film in tens of micrometers. The multifunctional film can be potentially used as high-performance and long-lifespan coating in sports goggles, car windows, glass houses, etc., under various environmental conditions. (DOI: 10.1002/pol.20220481)

A novel free-halogen flame retardant (trimethylolphosphine carbamate, THPON) was synthesized through the simple reaction between tetrakis(hydroxymethyl) phosphonium chloride and urea. Small molecule THPON could infiltrated the cotton fibers and grafted on cotton cellulose by amide bond. What is more, THPON did not change the inherent crystal structure of cotton because it infiltrated into the amorphous region of cotton. THPON-treated cotton was easily decomposed into phosphoric acid or polyphosphate at lower temperature and exhibited good flame retardancy due to the N/P synergistic effect. Compared to control, the heat release rate of THPON-treated cotton increased slower, indicating that a protective carbon layer formed and acted as a barrier. In addition, THPON displayed the low cytotoxicity and biosafety. The development and properties of THPON could provide an important data for the further application in the industry.

Over the past century, synthetic polymers have had a transformative impact on human life, replacing nature-derived materials in many areas. Yet, despite their many advantages, the structure and function of synthetic polymers still appear rudimentary compared to biological matter: cells use dynamic self-assembly to construct complex materials and operate sophisticated macromolecular devices. The field of DNA nanotechnology has demonstrated that synthetic DNA molecules can be programmed to undergo predictable self-assembly, offering unparalleled control over the formation and dynamic properties of artificial nanostructures. Intriguingly, the principles of DNA nanotechnology can be applied to the engineering of soft programmable materials, bringing the abilities of synthetic polymers closer to their biological counterparts. In this perspective, we discuss the unique features of DNA-functionalized polymer materials. We describe design principles that allow researchers to build complex supramolecular architectures with predictable and dynamically adjustable material properties. Finally, we highlight two key application areas where this biologically inspired material class offers particularly promising opportunities: (1) as dynamic matrices for 3D cell and organoid culture and (2) as smart materials for nucleic acid sequencing and pathogen detection.

Photosensitive polyimides (PSPIs) have been widely used in the buffer coating layer and insulation layer due to their excellent thermal and mechanical stability. In this work, a series of negative-type PSPIs based on poly(amic acid) (PAA) and a photobase generator (PBG) have been developed. Two diamines of 4,4′-oxydianiline (ODA), 3,3′-diaminodiphenyl sulfone (SDA), and four dianhydrides of pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 4,4′-oxydiphthalic anhydride (ODPA) and cyclobutene-1,2,3,4-tetracarboxylic dianhydride (CBDA) are copolymerized to PAA through polyaddition, and the PAA is further thermally imidized to polyimide (PI). Through scrutinizing the structure–sensitivity relationship of these PIs, we find that the rigidity and transparency of the PAA/PI backbone play an important role in the sensitivity and contrast of PSPI. Accordingly, PSPI (SDA-ODPA), possessing high optical transparency and a low rigidity represented by the low glass transition point, is capable of providing good photosensitivity of 30 mJ/cm², a high contrast of 2.46, and an excellent pattern resolution of 4 μm after optimizing the prebaking (100°C for 5 min), exposure dose (380 mJ/cm²), post-exposure baking (130°C for 7 min), and development parameters. This work provides the concept of structural design for negative-type PSPI in the microelectronic application.

C-reactive protein (CRP) is a member of the pentraxin protein group. CRP is considered an acute-phase protein produced by the liver during inflammation in various diseases limited to pathogenic infections. It is very important that serum CRP concentration can be measured quickly, reliably and easily. Therefore, a three-dimensional crosslinked molecularly imprinted polymer (MIP) with selective recognition sites for CRP was synthesized (CRP-MIP) and characterization analyzes (scanning electron microscopy, Fourier transform infrared, and thermogravimetric analysis) were performed. The binding abilities of the synthesized polymers by adsorption of CRP in aqueous solution were evaluated in detail and compared with the abilities of an unprinted polymer (CRP-NIP) used as a reference. It was found that the MIP prepared by the printing effect selectively adsorbed the template molecule CRP. For this effect, the selectivity of MIP toward CRP and various positive acute-phase reactants such as α1-antitrypsin and α1-acid glycoprotein was evaluated and high selectivity toward CRP was obtained. CRP-MIP was used to remove CRP from crude human serum, and the recovery was up to 91%. Adsorption process of CRP from aqueous solutions on polymeric adsorbents; equilibrium was evaluated in terms of kinetic and thermodynamic conditions and the necessary parameters to describe the process were calculated under these conditions. Adsorption data: the pseudo-first order kinetic model, the pseudo-second order kinetic model, the Elovich kinetic model and the intraparticle diffusion model were studied and the thermodynamic parameters ΔG°, ΔH°, and ΔS° were calculated.

Layered double hydroxides (LDHs) are popular functional fillers increasingly used in composite materials. They can be designed via metal and anion selection as well as the specific processing method to prepare structures with desired functional properties. This makes LDHs suitable for many different applications, including as flame-retardants, UV stabilizers, and anti-microbial agents in polymer nanocomposites as well as a photo-absorber in a solar cell. Here an overview of LDH synthesis and modification, composite preparation as well as characterization is given to highlight the unique ability for customization of LDH.

The ring-opening polymerization (ROP) of glycolide (GA), the copolymerization of GA with ε-caprolactone (ε-CL), and the terpolymerization of GA with ε-CL and lactide (LA) were studied over the cheap non-toxic metal-free organocatalyst tetrabutylammonium 2-(carbamyl)benzoate (TBACB). The catalyst with comparable catalytic activity to the comonomers afforded a series of well-defined PGA-based block polymers with ε-CL, LA monomers at high yields by varying feeding methods under bulk and solution conditions. The poly(ɛ-caprolactone-b-glycolic acid)s (PCGAs) and poly(ε-caprolactone-b-lactide-b-glycolide) (PCLGAs) with controllable chain segment composition were obtained by “one-pot” solution copolymerization in mixtures, or semi-batch copolymerization. Due to the high thermal stability of TBACB, the PCGA and PCLGA with high molecular weight (M_n = 6.9 and 10.0 kg mol⁻¹) could also be obtained by bulk polymerization at 120 °C by sequential addition of ε-CL, (LA), and GA in a short time (<2.5 h). Compared to the polymers with similar compositions by different methods, the bulk polymerization showed more effective and higher molecular weight. The microstructure characterized by NMR showed highly ordered block polymers with defined chain segments. Two melting transitions (T_m) of PCGA suggested exclusively associated with PCL and PGA segmental chain in the product.

Understanding the effective charge of colloidal particles is crucial to control the stability and performance of a colloidal system. In particular, the electrostatic interaction potential between the particles determines the stability and thermodynamic properties of electrostatically charged colloidal dispersions. In the case of thermosensitive microgels, which are solvent and ions permeable particles, it is expected that the microgel's size and the number of ions within it are affected by temperature changes. This temperature-dependent microgel-solvent ion interchange regulates the microgel net charge and, consequently, the interaction potential. Here, a straightforward experimental method based on conductivity measurements is presented to determine the temperature dependence of the effective net charge of poly-N-isopropylacrylamide, PNIPAM, microgels under different salinity conditions. Our results show that the net charge of the microgel decreases with increasing temperature. Specifically, microgels reduce their net charge by around 40%, when the temperature is changed from 25 to 40 °C. This scenario could be explained by the entrance of counterions into the microgel after its collapse to partially neutralize the increase of the electrostatic repulsion due to the closer proximity among the charged groups present in the polymer particle.

To enhance mechanical properties and processing performance of poly(ethylene terephthalate) (PET), it was upcycled to processable PET vitrimers with different crosslinking degrees by introducing dynamic network. The thermodynamics and linear viscoelasticity of PET vitrimers were explored by non-isothermal crystallization, isothermal sweep, frequency sweep and stress relaxation after incorporation of network. In particular, rheology experiments are sensitive to network structure and bond exchange mechanism in vitrimers. The pseudo-master curves show that relaxation processes are composed of three characteristic regions: Rouse-type relaxation of network strands, rubbery plateau and terminal relaxation of network, which is consistent with reversible gelation (RG) model. Two distinct (flow and chemical reaction) activation energies, are obtained by time–temperature superposition principle due to different temperature dependences of two relaxation behaviors. In addition, nonlinear rheology of PET vitrimers was investigated by extensional flow and start-up shear at the same Weissenberg number, and obvious strain hardening behavior were observed in all vitrimers. However, vitrimers with different crosslinking density exhibited distinct strain hardening trends as increase of extensional rate, corresponding to the ductility of material. On the basis of kinetics study, self-repairing and welding properties are further quantitatively explored for industrial applications.