Enhancing mechanical properties of thermoplastic polyurethane elastomers with 1,3-trimethylene carbonate, epsilon-caprolactone and L-lactide copolymers via soft segment crystallization

Abstract

Abstract. Multiblock thermoplastic polyurethane elastomers based on random and triblock copolymers were synthesized and studied. Dihydroxyl-terminated random copolymers were prepared by ring opening copolymerization of !-caprolactone (CL) and 1,3-trimethylene carbonate (TMC). The triblock copolymers were synthesized by using these random copolymers as macro-initiator for the L-lactide (L-LA) blocks. These random and triblock copolymers were further reacted with 1,6-hexamethylene diisocyanate (HMDI) and chain extended by 1,4-butanediol (BDO). The polymer structure and chemical composition were characterized by 1 H NMR 13 C NMR and SEC. Their thermal and mechanical properties were studied by using DSC and Instron microtester. Multiblock polyurethanes based on random PCL-co-PTMC copolymers showed strain recovery improvement with increasing PCL content. However, these polyurethanes were unable to sustain deformation at body temperature due to the melting of PCL crystals and low hard segments content. With the presence of crystallizable PLLA blocks, mechanical properties were improved at body temperature without compromising their good strain recovery.

Enhanced mechanical properties of PLA/PLAE blends via well-dispersed and compatilized nanostructures in the matrix

“…This nding is attributed to the chain reorganization of PLAE during the DSC test, and to the ne dispersion of the short uncrystallized HDI/BDO hard segment in the PLA and PLAE domains. 36 The PLAE polyurethane in this study shows a T g below room temperature, indicating a rubber-like amorphous structure. The presence of T g s from PLAE and PLA indicates poor miscibility of the PTMEG and PLA components, which is consistent with the FTIR results.…”

Biodegradable poly(trimethylene carbonate‐b‐(L‐lactide‐ran‐glycolide)) terpolymers with tailored molecular structure and advanced performance

“…Many authors have claimed that the copolymerization of L ‐lactide ( L LA) with 1,3‐trimethylene carbonate (TMC) can be a successful route to modify both mechanical properties and biodegradation rate of P L LA . Hence, some copolymers based on L LA and TMC have been realized and used in commodity as high‐performance medical biomaterials …”

“…[26][27][28] Hence, some copolymers based on LLA and TMC have been realized and used in commodity as high-performance medical biomaterials. [29][30][31][32][33] In previous work, we have investigated PTMC-LLA copolymers synthesized by random copolymerization with different compositions and chain structures. [34][35][36] It appears that the incorporation of TMC component significantly enhances the toughness and reduces the acidity of degradation products compared with pure PLLA.…”

The effect of change of ionomer/polyol molar ratio on dispersion stability and crystalline structure of films produced from hydrophilic polyurethanes

“…The hard‐segment content affects the microstructure of the polyurethane . Consequently, physical properties such as thermal and mechanical properties can be varied by varying the hard‐segment content in the polyurethane . One way to obtain polyurethanes having different hard‐segment content is by varying chain extender/polyol molar ratio while maintaining a constant NCO/OH molar ratio .…”