摘要
为了制备兼具有序度高和热力学性能稳定的聚酰亚胺(PI)薄膜,在联苯四甲酸二酐-对苯二胺(BPDA-PDA)体系中引入均苯四甲酸二酐(PMDA)单体,通过无规共聚法制备了PI薄膜,采用XRD、TMA、DMA、TGA、棱镜耦合仪和万能试验机对PI薄膜聚集态结构和物理力学性能进行分析。结果表明:不同二酐组成对PI薄膜的聚集态结构和热力学性能有显著影响,随着PMDA-PDA链段组分的增加,分子链有序度得到提高,分子链间距从0.469 nm降低至0.436 nm;双折射值在0.17~0.23内呈上升趋势,玻璃化转变温度(T_(g))在379.00~439.05℃内先下降后上升,热膨胀系数(CTE)在0~7×10^(-6) K^(-1)内先上升后下降,拉伸强度和5%热分解温度(T_(5%))分别在165~226 MPa和576.8~590.4℃内呈下降趋势。当PMDA摩尔分数为60%时,薄膜的双折射率达到最高值0.22471,T_(g)为439.05℃,CTE为0.0125×10^(-6) K^(-1),耐热指数(T_(HRI))达到302.0℃,T_(5%)达到576.8℃,综合热力学性能优异。
In order to prepare polyimide(PI)films with high order degree and stable thermomechanical properties,pyromellitic dianhydride(PMDA)monomer was introduced into biphenyltetracarboxylic acid dianhydride-p-phenylenediamine(BPDA-PDA)system,and PI films were prepared by random copolymerization method.The aggregation structure and physical properties of the PI films were analyzed by XRD,TMA,DMA,TGA,prism coupling instrument,and universal testing machine.The results show that different dianhydride composition has a significant effect on the aggregation structure and thermal mechanical properties of PI films.With the increase of PMDA-PDA segment composition,the molecular chain order degree increases,and the molecular chain spacing decreases from 0.469 nm to 0.436 nm.The birefringence value shows an upward trend in the range of 0.18‒0.22.The glass transition temperature(T_(g))decreases at first and then increases in the range of 379.86‒439.05℃.The thermal expansion coefficient(CTE)increases at first and then decreases in the range of 0‒7×10^(-6) K^(-1).The tensile strength and 5%thermal decomposition temperature(T_(5%))show a downward trend in the range of 166‒225 MPa and 576.8‒590.4℃,respectively.When the mole fraction of PMDA is 60%,the PI film has excellent comprehensive properties with 0.22 of birefringence,439.05℃of T_(g),0.0125×10^(-6) K^(-1) of CTE,302.5℃of heat resistance index(T_(HRI)),and 576.8℃of T_(5%).
作者
李诗卉
马传国
戴培邦
青双桂
LI Shihui;MA Chuanguo;DAI Peibang;QING Shuanggui(School of Material Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China;Guangxi Key Laboratory of Electronic Information Materials,Guilin 541004,China;Engineering Research Center of Ministry of Education for Electronic Information Materials and Devices,Guilin 541004,China;Guilin Electrical Equipment Scientific Research Institute Co.,Ltd.,Guilin 541004,China)
出处
《绝缘材料》
CAS
北大核心
2021年第11期108-113,共6页
Insulating Materials
基金
国家自然科学基金资助项目(51763006)
广西科技重大专项课题(桂科AA18242010-2)。
关键词
聚酰亚胺薄膜
聚集态结构
热膨胀系数
热力学性能
polyimide film
aggregate structure
coefficient of thermal expansion
thermomechanical property
