Largely improved mechanical properties of a biodegradable polyurethane elastomer via polylactide stereocomplexation

Publication date: 14 February 2018
Source:Polymer, Volume 137
Author(s): Haili Wang, Jiangtao Yu, Huagao Fang, Haibing Wei, Xiaohong Wang, Yunsheng Ding
Thermoplastic polyurethane elastomers (PUEs) consisting of biodegradable poly (ε-caprolactone) (PCL) and low toxic aliphatic diisocyanates are of great potential in biomedical applications, but the inferior mechanical strength and elastic recovery at large strain have limited their practical utilization. Inspired by the outstanding thermal and mechanical properties of stereocomplex (SC) PLA, a thermoplastic PUE that contains SC crystallites (SC-PU) was prepared via racemically blending the PLA stereoisomers-based polyurethanes. The formation of SC crystallites in SC-PU was confirmed by WAXD and ATR-FTIR techniques. The effects of stereocomplexation on its thermal, morphological and mechanical properties were investigated. The results show that the SC crystalline domains, acting as 'additional reinforcing phases', endow the improved performance of SC-PU in tensile strength, Young's modulus, elastic recovery, and other properties. This study may provide a new method to improve the inferior mechanical properties of biodegradable PUEs based on PCL and aliphatic diisocyanates, which can contribute to the expansion of their applications in widespread fields.

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