摘要
采用两步法,以N,N-二甲基乙酰胺(DMAc)为溶剂,3,3′-4,4′-联苯四甲酸二酐(BPDA)、双酚A二酐(BPA-DA)、2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)、4,4′-二氨基二苯醚(ODA)为单体,制备二元二胺与二元二酐(四元)共聚聚酰亚胺(PI)薄膜。以傅里叶变换红外光谱仪(FTIR)表征所得PI薄膜的分子结构,以差示扫描量热仪(DSC)测定其玻璃化转变温度(Tg)、热重分析仪(TG)测定其热稳定性,以紫外-可见分光光度仪(UV-Vis)及色差仪测定其光学性质,低场核磁共振成像分析仪(LFNMR)测定薄膜中水分布状态。结果表明,所制备的四元共聚PI薄膜实现完全亚胺化,热失重5%温度(T5%)高于499℃;薄膜含有少量的结合水和不易流动水,不含自由水;Tg高于210℃;相较于一元二胺与一元二酐(二元)均聚PI薄膜及一元二胺与二元二酐共聚PI薄膜和二元二胺与一元二酐(三元)共聚PI薄膜,四元共聚PI薄膜具有更好的透光率和无色性,在465 nm波长处的紫外-可见光透光率(T465nm)最高达92%,黄度指数(b∗)最低至8.58,Tg下降。四元共聚PI薄膜的Tg低于二元均聚及三元共聚PI薄膜的Tg,说明四元共聚PI薄膜的分子链间自由体积增大,是导致PI薄膜透光性提高和黄度下降的原因。
The binary diamine and binary dianhydride(quaternary)copolymerized polyimide(PI)films were prepared by a two-step method using N,N-dimethylacetamide(DMAc)as solvent,3,3′-4,4′-biphenyltetracarboxylic acid dianhydride(BPDA),bisphenol A dianhydride(BPADA),2,2-bis[4-(4-aminophenoxy)phenyl]propane(BAPP),4,4′-diaminodiphenyl ether(ODA)as monomers.The molecular structures of the resulting PI films were characterized by Fourier transform infrared spectroscopy(FTIR),the glass transition temperatures(Tg)were determined by differential scanning calorimetry(DSC),the thermal stability was tested by thermogravimetric analyzer(TG),the optical properties were tested by ultraviolet-visible spectrophotometry(UV-Vis)and chromatic aberrometry,and the water distribution status in the films was tested by low-field nuclear magnetic resonance(LFNMR)analyzer.The results show that the prepared quaternary copolymer PI films achieve complete imidization,the thermal weight loss 5%temperature(T5%)is higher than 499℃.The films contain a small amount of bound water and not easily flowable water,and no free water.The glass transition temperature(Tg)is higher than 210℃.Compared to the mono diamine and mono dianhydride(dibasic)homopolymer polyimide(PI)films,mono diamine and dibasic anhydride copolymer PI films,and the diamine and mono dianhydride(ternary)copolymer PI films,the tetramer copolymer PI films have better transmittance and colorlessness,with a transmittance(T465 nm)up to 92%at 465 nm,a yellowness index(b∗)as low as 8.58,and a decreased Tg.The Tg of the quaternary copolymer PI films is lower than that of dibasic copolymer and ternary copolymer PI films,indicating that the increase in the free volume between the molecular chains of the quaternary homopolymer PI films is responsible for the transmittance increase and yellowness decrease of the PI films.
作者
刘伟伟
戴培邦
张倍铭
LIU Weiwei;DAI Peibang;ZHANG Beiming(School of Materials Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China;Guangxi Key Laboratory of Structure-Activity Relationship for Electronic Information Materials,Guilin University of Electronic Science and Technology,Guilin 541004,China)
出处
《塑料工业》
北大核心
2025年第1期24-30,共7页
China Plastics Industry
关键词
聚酰亚胺
无色透明
四元共聚
Polyimide
Colorless and Transparent
Quaternary Copolymerization
