Kinetic study of low-temperature imidization of poly(amic acid)s and preparation of colorless, transparent polyimide films
作者:Hwan-Chul Yu、Jae-Woo Jung、Ju-Young Choi、Chan-Moon Chung
DOI:10.1002/pola.28013
日期:2016.6.1
Conventional synthesis of polyimides includes high‐temperature (160–350 °C) imidization of poly(amic acid)s. In the present work, imidization has been carried out at much lower temperatures (40–160 °C). 1,2,4,5,‐cyclohexanetetracarboxylic dianhydride (HPMDA) or pyromellitic dianhydride (PMDA) was polymerized with an aromatic diamine, 4,4′‐diaminodiphenylmethane (DDPM), to give poly(amic acid)s, which were
聚酰亚胺的常规合成包括高温(160-350°C)的聚(酰胺酸)酰亚胺化。在目前的工作中,酰亚胺化反应是在较低的温度(40–160°C)下进行的。将1,2,4,5,-环己烷四甲酸二酐(HPMDA)或均苯四酸二酐(PMDA)与芳族二胺4,4'-二氨基二苯甲烷(DDPM)聚合,得到聚(酰胺酸),然后将其酰亚胺化化学地。甚至在40°C的极低酰亚胺化温度下,亚胺化反应仍可完成90%以上。发现亚胺化发生在两个步骤中:最初的快速环化和随后的较慢的环化。确定快速过程的活化能为4.3 kJ / mol,而较慢过程的活化能为4.8 kJ / mol。随着酰亚胺化温度的降低,所得聚酰亚胺的透射率趋于逐渐增加,截止波长减小并且颜色变浅。在40°C下制备的基于HPMDA和DDPM的部分脂肪族聚酰亚胺,生成的薄膜高度透明无色,并具有良好的柔韧性,溶解性和热稳定性。在这项研究中制备的聚酰亚胺薄膜可能是显示器行业中柔性,透明塑料基材的理想选择。©2015