An innovative strategy to regulate bimodal cellular structure in chain extended poly(butylene adipate‐ <i>co</i> ‐terephthalate) foams
Yalin Cui, Haoyan Zhou, Haoyan Zhou, Dexian Yin, Hongfu Zhou, Hongfu Zhou, Xiangdong Wang
Abstract
Abstract A facile and effective approach for manufacturing poly(butylene adipate‐ co ‐terephthalate) (PBAT) foams with obvious bimodal cellular structure (BCS) was proposed utilizing chain extension and batch supercritical CO 2 foaming technology. Ethylene‐glycidyl methacrylate copolymer (EGMA) as crystalline chain extender was selected to modify PBAT. The results of torque tests, differential scanning calorimetry, and rheological performances demonstrated that the melt strength, viscoelasticity, and crystallization properties of PBAT were improved after introducing EGMA. The influences of EGMA content and foaming temperature on the cellular structure of PBAT foams were investigated systematically. By decreasing the foaming temperature, the size of both large and small cells in the bimodal chain extended PBAT‐3 (CPBAT‐3) foams decreased, as well as their BCS became distinct gradually. The BCS in diverse CPBAT foams was successfully controlled via varying EGMA content and foaming temperature. Finally, the formation mechanism of BCS in diverse PBAT foams was presented.