Open porous morphology evolution in poly (butylene succinate)/chitin nanocrystal nanocomposite foams

In recent decades, biodegradable polymeric open-porous foams have been engaging increasing interests owing to their biodegradability, porosity and biocompatibility. In this work, biodegradable poly(butylene succinate) (PBS)/chitin nanocrystals (ChNCs) nanocomposite foams with open porous structure were successful fabricated by a solid-state batch foaming method. ChNCs were obtained from chitin by using sulfuric acid treatment and then introduced into PBS. The incorporation of ChNCs had a positive effect on the crystallization behaviors, melt viscoelasticity and thermal stability of diverse PBS specimens. Compared with the change of foaming temperature, the addition of ChNCs would cause a prominent influence on the open porous structure of diverse PBS foams. The probable explanation was that during the foaming process, the spherulites and/or ChNCs as the hard region in PBS could be served as pore wall and the amorphous area as the soft region was acted as pore, leading to open porous PBS foams. The reported strategy in this work could provide the guidelines to regulate and control open porous foams in other semi-crystalline polymer matrices.