Autoclave Foaming of Poly(epsilon-Caprolactone)Using Carbon Dioxide:Impact of Crystallization on Cell Structure

摘要

The purpose of this study is to develop a better understanding of the main mechanisms controlling the foaming of poly(epsilon-caprolactone)(PCL),a semi-crystalline biodegradable polymer,using batch processing and CO2 as the physical blowing agent.A detailed study of the dissolution of CO2 is conducted in order to establish its impact on the transition temperatures of PCL.In a following step,particular attention is paid to the effects of crystallization on cell structure.This foam structure is subsequently linked to the processing window,expressed in terms of the processing temperature with respect to the shifted crystallization temperature and modified crystallization kinetics of PCL.The effects of talc addition on PCL crystallization and foam structure are also investigated,as talc is expected to modify the nucleation rate of crystallites and cells.