低玻璃轉移溫度熱安定聚亞醯胺之製備與特性研究

Abstract

本論文主要以高熱安定性、低玻璃轉移溫度之聚亞醢胺的製備為研究目的，期許擁有此特性之聚亞醢胺能在黏著特性上有較優良的表現，可在聚亞醢胺黏著劑方面有所應用。為此，以三步驟合成了具有四個苯環，三個醚基架橋的二酸酐BPEA，及用兩步驟合成具兩個羰機三個苯環的間位二胺m-BABB，期許因醚基價橋對柔曲性的助益與羰基的高熱定性，達到降低Tg、保持熱安定性、增進黏著力的目的。 以BPEA合成一系列聚亞醢胺，發現其眾醢胺酸的固有黏度分佈在0.54∼0.6間，具良好成膜性，合成之分子量，僅隨二胺因結構上造成之反應性不同而稍有改變；Tg的確因其醚基架橋數的增加而有顯著的下降，黏著能力僅以臨界表面能來看，與醚基多寡、取代基位置（間位、對位）有某種程度上的關係，雖然Tg降低，仍能維持熱安定性，其5％重量損失在510℃∼550℃之間。 以m-BABB與二胺m-BAPS同二酸酐BTDA共聚合成之聚亞醢胺的性質，受m-BABB影響很大，因m-BABB結構上反應性較慢，且雙羰基間位組成造成鏈段較具扭曲性，使其玻璃轉移溫度及臨界表面能，隨添加m-BABB的比例增加而下降，5%的重量損失溫度不隨m-BABB的比例而明顯的有所改變，其間可能在高溫下羰基與其他鏈段產生交聯作用(Cross-linking)。

Polyimide adhesives requre relatively low Tg and high thermal stability. For these purposes, we used three-steps procedure to synthesize dianhydride BPEA which has four benzene ring and three ether-linkage. While diamine m-BABB which has amino group and two carbonyl group located in meta-position were synthesized by two-steps procedure. More ether-linkage was used to lower Tg and increase flexibility of polymer chain, while carbonyl group was used to increase thermal stability and charge-transfer ability. We hope that these functional group can increase adhesion adility of polyimides. These two monomer were characterized carefully. Thermal properties, surface energy, and mechanical properties of polyimides were measured. We used BPEA to react with different diamines to synethesize a series of polyimides, inherent viscosity of polyamic acid were ranging from 0.54 to 0.6, which can be easily casting and thermally curing as thin film. Their Tg indeed became lower with more ether-linkage. Meta-position diamine had much lower Tg than para-position one. Critical surface energy basically changed with their Tg. The5%-weight-loss were ranging from to 550℃. We used diamine m-BABB and m-BAPS to copolymerize with dianhydride BTDA Their Tg, critical surace energies were lower with more percentage of m-BABB, While 5%-weight-loss and mechanical properties remain the same level. It seems not to be influences by the presence of m-BABB.