硬质闭孔聚酰亚胺结构泡沫的结构调控与性能

The Structure and Property of Rigid Closed-Cell Polyimide Foams

通过调控聚酰亚胺(PI)树脂主链结构中二苯羰基链段与不对称联苯链段的含量比例,制备了具有不同羰基含量的PI前驱体固体树脂。这些前驱体树脂都具有良好的熔融性,当加热至320~330℃时,PI树脂完全熔融形成低粘度熔体树脂;进一步提高加热温度时树脂熔体粘度由于发生交联反应而急剧增大。将前驱体树脂经加热发泡形成的热固性硬质闭孔PI泡沫具有很高的闭孔率(】86%)和耐热性能(Tg】353℃,T10】519℃)。研究发现,在PI树脂主链结构中引入二苯甲酮链段可明显提高PI泡沫的韧性,而不会牺牲其力学强度和模量。

Through regulating the content and proportion of biphenyl carbonyl and unsymmetrical biphenyl segments in polyimide resin backbone,polyimide precursor solid resins with different carbonyl content were prepared.These precursor resins have good meltability,when heated to 320~330℃,PI resin completely melted,resulting in low melt viscosity resin,as the temperature increased further,the melt viscosity increases rapidly due to the crosslinking reaction.The precursor resins were heated and foamed,forming the thermosetting rigid closed-cell PI foams which have high closed-cell rate(>86%)and high thermal properties(Tg>353℃,T10 >519℃).The study found that the introduction of the biphenyl carbonyl segment into the PI resin main chain could obviously improve the PI foam toughness without sacrificing its mechanical strength and modulus.