▎ 摘　　要

In this article, a facile and green strategy of nonisothermal crystallization induction was proposed to produce nanocellular biodegradable polymer composite foams, which was demonstrated by a composite system of poly(butylene succinate) (PBS) modified by hydroxyl-functionalized graphene (HG) and chain extender. Nanocellular foams of chain extended PBS (CPBS) and CPBS/HG composite were prepared successfully with supercritical CO2. Two significant phenomena about the preparation of nanobubbles in CPBS and CPBS/HG composite foams were found. One was that the nanobubbles generated at the temperature region of crystallization transition and the other was that chain extension played a critical function in the generation of nanobubbles. As the foaming temperature switched from 86 to 85 degrees C, an interesting microbubble to nanobubble transition in CPBS and CPBS/HG foams was observed. Due to the generation of nanobubbles and the enhancement of volume expansion ratio, an excellent thermal insulation performance was achieved by CPBS/HG foams. (c) 2020 Society of Plastics Engineers