基于AB型单体聚醚酰亚胺共聚物的合成与性能

Synthesis and Properties of Polyetherimide Copolymers Based on AB-type Monomer

摘要:

改变AB型单体3-氨基-5,6,9,10-四氢-[5]螺旋烯-7,8-二羰基-二甲酸酐（ATHDA）的用量，使之与4,4'-(4,4'-异亚丙基二苯氧基)双(邻苯二甲酸酐)（BPADA）和2-氨基二苯醚（ODA）共聚，制备出一系列ATHDA结构单元含量不同的聚醚酰亚胺PEI-ABx（x分别为0%、5%、10%、15%、20%，表示以BPADA和ODA的总质量为基准计算得到的ATHDA的投料比）。采用FTIR、1HNMR、DSC、DMA、TGA 等对聚合物进行了表征。结果表明，所制备的PEI-ABx特性粘度在0.60~0.87 dL/g之间，均具有良好的成膜性，且该系列聚合物均具有优异的溶解性；由DMA所测得的玻璃化转变温度（Tg）在228~256 °C之间，N2气氛下5%的热失重温度（T5%）为505~536 °C，表明PEI-ABx具有优异的热稳定性；聚合物薄膜的拉伸强度、杨氏模量和断裂伸长率分别在41.7~88.1 MPa、1.7~2.7 GPa 和3.3%~4.8%的范围内，具有良好的机械性能。另外，聚合物分子链中的四氢-[5]螺旋烯结构可脱氢芳香化， PEI-AB20%脱氢芳香化后的聚合物Tg从256 °C提高至283 °C， T5%从531 °C提升至557 °C，表明芳香化后的聚合物耐热性得到进一步提升。

Abstract:

A series of polyetherimides PEI-ABx (x were 0%, 5%, 10%, 15% and 20%, respectively, indicating the content of ATHDA based on the total mass of BPADA and ODA) were synthesized from AB-type monomer 3-amino-5,6,9,10-tetrahydro-[5]helicene-7,8-dicarbonyl-dicarboxylic anhydride (ATHDA), 4,4'-(4,4'-isopropylidenediphenyloxy) bis-(phthalic anhydride) (BPADA) and 2-aminodiphenyl ether (ODA). The polymers were characterized by FTIR, 1HNMR, DSC, DMA and TGA. The results showed that the inherent viscosity numbers of the PEI-ABx were 0.60~0.87 dL/g. All of the polymers had good film-forming property and solubility. The glass transition temperatures (Tg) measured by DMA were 228~256 °C, and the 5% thermogravimetric temperatures (T5%) were 505~536 °C in N2 atmosphere, which indicated that the PEI-ABx had excellent thermal stability. The tensile strength, young's modulus and elongation at break of the polymer films were 41.7~88.1 MPa, 1.7~2.7 GPa and 3.3%~4.8%, respectively, demonstrating that the PEI-ABx possessed good mechanical properties. In addition, the tetrahydro - [5] helicene structure in polymer chains could be dehydrogenated to form more rigid aromatic structure. For PEI-AB20%, after dehydrogenation the Tg and T5% of the polymer were increased from 256 °C to 283 °C, and 531 °C to 557 °C respectively. The results showed that the heat resistance of the polymers could be further improved by dehydrogenation.