Research progress of carbon material in the stereocomplex crystallization of poly (lactic acid)

Polylactic acid (PLA) is a biodegradable and biocompatible polymer. Because of its good mechanical properties and outstanding thermoplasticity, it has excellent potential for substitution of petroleum-based polymers. However, the slow crystallization rate, low crystallization and poor heat resistance of PLA, seriously restrict its wide application and development. It has been established that formation of stereocomplex (SC) crystallites is an effective way to improve the various performance of PLA. Nevertheless, SC crystallites are difficult to controllable formation in the actual production and application of PLA. As a green nucleating agent, carbon material could adjust the SC crystallization. This paper describes the crystal structures of HC and SC formed by PLA, sorts out the researches about carbon additives on the effect of SC crystallization and discusses the possible mechanism for carbon additives promoting SC crystallization of PLA. Finally, the current challenges are pointed out and the future research directions are prospected.