Thermoplastic polyurethanes based on poly(dimethylsiloxane): structure and thermal behavior

Segmented polyurethanes are an important class of thermoplastic elastomers which have potential use as a biomaterial. Biostability, biocompatibility and some other features of polyurethanes can be improved by the introduction of poly(dimethylsiloxane) in the polymer chain. A series of novel thermoplastic polyurethanes was synthesized by two-step polyaddition reaction in solution from 4,4′-diphenylmethane diisocyanate (MDI), 1,4- butanediol (BD) and poly(propylene oxide)-b-poly(dimethylsiloxane)-bpoly(propylene oxide) (PPO-PDMS). The content of PPO-PDMS (i.e. soft segment) was varied between 40 and 90 wt%. The influence of PPO-PDMS content on the structure and thermal properties of copolymers was investigated by FTIR, 1H and 2D NMR spectroscopy, as well as by DSC analysis