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Polyurethane (PU) is a versatile material that can be customized to meet specific commercial requirements in different industries because of its favorable mechanical properties. However, it is not resistant to high temperatures, and it requires structural modifications before it can be used in high‐temperature structural materials. In this study, isocyanates and anhydrides are copolymerized at high temperatures to obtain a solvent‐free oligomer, thus eliminating the risks associated with highly polar aprotic solvents. A casting technique is used to synthesize a solid poly(urethane‐imide) (PUI) elastomer. According to the results, casting PUI (CPUI) exhibits optimal physical properties at a hard segment content of 30.5%. Incorporating an ether, symmetric, or imide structure into CPUI may reduce its hysteresis and improve its thermal creep performance. Compared with PU, CPUI exhibits considerably higher creep aging resistance. In dynamic load application tests, CPUI wheels take a substantially longer time to reach failure compared with PU wheels. Overall, CPUI is an environmentally friendly material with high elasticity, low creep, and high heat aging resistance and is suitable for static and dynamic manufacturing applications. [ABSTRACT FROM AUTHOR]

9,9-bis[4-(2-hydroxy-3-acryloyloxypropoxy)phenyl]fluorene (BPF) hydroxyl groups (-OH) were used as initiators in the ring-opening polymerization reaction with DL-lactide monomers at different molar ratios to synthesize a Poly(DL-lactide) polymer containing bisphenol fluorene structure and acrylate functional groups (DL-BPF). The polymer's structure and molecular weight range were analyzed using NMR (1H, 13C) and gel permeation chromatography. DL-BPF was then subjected to photocrosslinking using the photoinitiator Omnirad 1173, resulting in the formation of an optically transparent crosslinked polymer. Characterization of the crosslinked polymer involved analyzing its gel content, refractive index, thermal stability (via differential scanning thermometry (DSC) and thermogravimetric analysis (TGA)), as well as conducting cytotoxicity tests. The crosslinked copolymer exhibited a maximum refractive index of 1.5276, a maximum glass transition temperature of 61.1 °C, and cell survival rates higher than 83% in the cytotoxicity tests. [ABSTRACT FROM AUTHOR]

PCL-based biodegradable shape-memory polymers (SMPs) are limited in strength, which restricts their practical applications. In this study, a series of novel SMPs, composed of poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and poly(ε-caprolactone) (PCL), were synthesized and cross-linked using planar (benzene-1,3,5-tricarboxylic acid, BTC) or non-planar (glycerol, GC) cross-linkers via the one-pot method. The influence of different kinds of cross-linkers and hard segments of copolyesters on the thermal properties, crystallization behavior, mechanical properties, shape-memory performance, and degradability was investigated by FT-IR, 1H-NMR, DSC, DMA, TGA, XRD, tensile test, intrinsic viscosity measurement, and in vitro enzymatic degradation test. The results indicate that the tensile strength of the copolyester can be significantly improved from 27.8 to 53.2 MPa by partially replacing PET with PEN while maintaining its shape-memory characteristics. Moreover, a small amount of cross-linking modification leads to higher temperature sensitivity, improved shape recovery rate at third round (Rr(3) = 99.1%), and biodegradability in the cross-linked PET/PEN/PCL shape-memory polymers. By changing the crystallization morphology and cross-linking forms of the material, we have developed a shape-memory polymer with both high strength and a high shape recovery rate, which provides a new strategy for the development of shape-memory materials. [ABSTRACT FROM AUTHOR]