The microcellular foaming of chain-extended polyethylene terephthalate (CPET) by crystallization induction method was reported in this article. The crystallization behaviors of various polyethylene terephthalate (PET) samples which were affected by the combined effect of pyromellitic dianhydride, Surlyn, and CO2 were investigated. After Surlyn was added to CPET, the crystal nucleation of various CPET samples was improved, and numerous but small spherulites were generated. Two kinds of CPET samples with the content of 0 phr and 1 phr Surlyn were foamed at various temperature by batch foaming method. Changing the saturation temperature could adjust the appearance of high-temperature melting crystals which would affect the final cellular structures in various CPET foams. With the decrease of saturation temperature, the cell size decreased while cell density increased. At the saturation temperature of 265°C and 250°C, the cell density of CPET foam with Surlyn was one magnitude larger than CPET foam without Surlyn. At the saturation temperature of 247°C, the microcellular PET foams with the cell density of 109 cells cm−3 and the cell size less than 10 µm had been developed successfully.

中文翻译：

---

扩链聚对苯二甲酸乙二醇酯的结晶诱导微孔发泡行为

本文报道了用结晶诱导法对扩链聚对苯二甲酸乙二醇酯（CPET）进行微孔发泡。研究了受均苯四酸二酐、Surlyn 和 CO2 共同作用影响的各种聚对苯二甲酸乙二醇酯 (PET) 样品的结晶行为。在CPET中加入Surlyn后，各种CPET样品的晶核形成得到改善，产生了大量但较小的球晶。采用分批发泡法，在不同温度下对含量为0份和1份Surlyn的两种CPET样品进行发泡。改变饱和温度可以调整高温熔融晶体的外观，这会影响各种 CPET 泡沫的最终蜂窝结构。随着饱和温度的降低，细胞大小减小而细胞密度增加。在 265°C 和 250°C 的饱和温度下，含 Surlyn 的 CPET 泡沫的泡孔密度比不含 Surlyn 的 CPET 泡沫大一个数量级。在247°C的饱和温度下，成功开发出泡孔密度为109孔cm-3、泡孔尺寸小于10μm的微孔PET泡沫。