基于乙炔基-苯并噁嗪单元双重交联反应的聚酰亚胺树脂的制备与性能

为开发可低温固化的聚酰亚胺树脂, 通过分子结构设计将苯并噁嗪单元引入聚酰亚胺树脂中, 合成了含苯并噁嗪单元及乙炔基封端的双官能化新型聚酰亚胺预聚体(PIBzA). 经高温处理, 苯并噁嗪单元发生开环交联, 同时, 乙炔基端基发生三聚成环反应, 从而在固化树脂中形成双重交联网络结构. 苯并噁嗪单元的引入使聚酰亚胺树脂最快固化反应温度降低约32 ℃, 有效降低了固化温度. 同时, 苯并噁嗪单元的引入未大幅度降低树脂的耐热稳定性, 其玻璃化转变温度(T_g)介于266~290 ℃之间, 5%热失重温度(T_d,5%)接近500 ℃, 依然可以满足耐高温复合材料的应用需求. 此外, PIBzA固化树脂具有低介电特性, 其介电常数k介于2.3~3.0, 介电损耗介于0.002~0.008, 可满足透波复合材料及先进微电子封装材料的应用需求.

Synthesis and Properties of Polyimide Resin Containing Acetylene and Benzoxazine Double Crosslinking Moieties

To develop high-performance polyimide resins that can be cross-linked at a relative low temperature， a novel polyimide resin（PIBzA） was designed and synthesized by introducing the benzoxazine ring into the acetylene-terminated polyimide oligomer. During the curing process， a ring-opening polymerization of benzoxazine and cross-linking of acetylene take place in the oligomer， and a novel double cross-linked network can be formed in the cured resin. Interestingly， an approximately 32 ℃ lower in curing temperature can be observed for this polyimide resin compared with the sample without the benzoxazine moiety. Meanwhile， the introduction of benzoxazine moiety does not destroy the excellent thermal resistance of polyimide resin， and the glass transition temperature（T_g） of the cured PIBzA resin ranges from 266 to 290 ℃， and the 5% mass loss temperature is close to 500 ℃. Meanwhile， the cured PIBzA resin shows relative low dielectric constants of 2.3―3.0 and low dielectric loss of 0.002―0.008， which can meet the requirements of wave-transparent composites and advanced microelectronic packaging materials.