Moon Kwan Ho, Chae Boknam, Kim Ki Seung, Lee Seung Woo, Jung Young Mee
School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea.
Pohang Accelerator Laboratory, POSTECH, Pohang 37673, Korea.
Polymers (Basel). 2019 Mar 13;11(3):489. doi: 10.3390/polym11030489.
Polyimide (PI) composite films with thicknesses of approximately 100 µm were prepared via a sol⁻gel reaction of 3-aminopropyltrimethoxysilane (APTMS) with poly(amic acid) (PAA) composite solutions using a thermal imidization process. PAA was synthesized by a conventional condensation reaction of two diamines, 3,5-diaminobenzoic acid (DABA), which has a carboxylic acid side group, and 2,2'-bis(trifluoromethyl)benzidine (TFMB), with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) in N,N-dimethylacetamide (DMAc). The PAA⁻silica composite solutions were prepared by mixing PAA with carboxylic acid side groups and various amounts of APTMS in a sol⁻gel process in DMAc using hydrochloric acid as a catalyst. The obtained PI⁻silica composite films showed relatively good thermal stability, and the thermal stability increased with increasing APTMS content. The optical properties and in-plane coefficient of thermal expansion (CTE) values of the PI⁻silica composite films were investigated. The CTE of the PI⁻silica composite films changed from 52.0 to 42.1 ppm/°C as the initial content of APTMS varied. The haze values and yellowness indices of the composite films increased as a function of the APTMS content.
通过3-氨丙基三甲氧基硅烷（APTMS）与聚酰胺酸（PAA）复合溶液的溶胶-凝胶反应，采用热亚胺化工艺制备了厚度约为100 µm的聚酰亚胺（PI）复合薄膜。PAA是由两种二胺，即具有羧酸侧基的3,5-二氨基苯甲酸（DABA）和2,2'-双（三氟甲基）联苯胺（TFMB），与4,4'-（六氟异丙基）二苯二甲酸酐（6FDA）在N，N-二甲基乙酰胺（DMAc）中通过常规缩合反应合成的。PAA-二氧化硅复合溶液是通过在DMAc中使用盐酸作为催化剂，在溶胶-凝胶过程中将带有羧酸侧基的PAA与不同量的APTMS混合制备的。所得的PI-二氧化硅复合薄膜表现出相对良好的热稳定性，并且热稳定性随着APTMS含量的增加而提高。研究了PI-二氧化硅复合薄膜的光学性能和面内热膨胀系数（CTE）值。随着APTMS初始含量的变化，PI-二氧化硅复合薄膜的CTE从52.0变为42.1 ppm/°C。复合薄膜的雾度值和黄度指数随APTMS含量的增加而增加。
