Benzocyclobutene in polymer synthesis. I. Homopolymerization of bisbenzocyclobutene aromatic imides to form high‐temperature resistant thermosetting resins
Benzocyclobutene in polymer synthesis. I. Homopolymerization of bisbenzocyclobutene aromatic imides to form high‐temperature resistant thermosetting resins
复制标题
DOI：
10.1002/pola.1988.080260712
复制
发表时间：
1988-07
期刊：
影响因子：
--
通讯作者：
Loon-Seng Tan;F. Arnold
中科院分区：
文献类型：
--
作者：
Loon-Seng Tan;F. Arnold
以4-氨基苯并环丁烯为原料，在无水乙酸/甲苯体系中与目标化合物二酐缩合，合成了一系列新型双苯并环丁烯封端的芳香酰亚胺单体。上述单体的差示扫描量热研究表明，聚合放热开始于229-250°C，并在258-263°C达到最大值。固化的样品（250-254°C; N2; 8小时）对于热氧化降解是令人惊讶地稳定的;在314°C（600°F）下200小时（在空气中）后仅观察到7-10%的重量损失。在较高的温度（650和700°F）下，最刚性的结构是最热氧化稳定的。提高双苯并环丁烯体系的最终玻璃化转变温度（Tgcure）和热氧化稳定性的方法是稀释固化位点密度，因为固化位点结构是聚合物结构的最弱部分。因此，我们以不同的芳香胺为扩链剂，合成了一系列双苯并环丁烯封端的芳香酰亚胺齐聚物，其中Meta-苯二胺对提高聚合物的Tg（固化温度）和热氧稳定性最为有效。
A series of new bisbenzocyclobutene‐terminated aromatic imide monomers has been synthesized from the condensation reaction of 4‐aminobenzocyclobutene and the perspective dianhydride in refluxing acetic acid/toluene. The differential scanning calorimetric studies of the foregoing monomers indicated that polymerization exotherms began at 229–250°C and reached their maxima at 258–263°C. The cured samples (250–254°C; N2; 8 h) were surprisingly stable toward thermo‐oxidative degradation; only 7–10% weight loss was observed after 200 h (in air) at 314°C (600°F). At higher temperatures (650 and 700°F), the most rigid structure was the most thermo‐oxidatively stable. An approach to enhance both the final glass‐transition temperature (Tgcure) and the thermo‐oxidative stability of the bisbenzocyclobutene system was to dilute the cure‐site density since the cure‐site structure is the weakest part of the polymeric structure. Therefore, a series of bisbenzocyclobutene‐terminated aromatic imide oligomers were prepared, using various aromatic amines as the chain‐extending agents.Meta‐phenylenediamine was apparently the most effective in the advancement of both theTg(cure) and thermo‐oxidative stability.