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机构地区:[1]西北工业大学理学院应用化学系,陕西西安710129
出 处:《现代化工》2011年第11期52-55,共4页Modern Chemical Industry
摘 要:使用均苯四甲酸酐(PMDA)作为A2型单体,2,46,-三氨基嘧啶(TAP)作为B'B2型单体,通过控制反应中二酐和三胺的滴加顺序及物质的量的比合成了一系列具有不同端基终端的超支化聚酰亚胺(HBPIs)。然后采用红外光谱(FT-IR)、核磁共振(1H-NMR)、凝胶渗透色谱(GPC)、热失重分析(TGA)、差示扫描量热仪(DSC)等对合成的超支化聚酰亚胺进行测试和表征。因为TAP中2-位氨基与4-,6-位氨基具有不同的反应活性,避免了聚合过程中凝胶的形成。结果表明:当二酐和三胺的物质的量的比从1∶1增大到2∶1时,其支化度增大,相对分子质量增大,而玻璃化转变温度和10%热失重温度相应降低。A series of" hyperbranched polyimides with different terminal groups are successtully prepared by changing monomer addition orders and molar ratios using pyromelliti~, anhydride ( PMDA ) as A2 monomers and 2,4,6- triaminopyrimidine(TAP) as B'B2 monomers. The obtained HBPIs" structures and performance are characterized by Fourier transform infrared spectroscopy ( FT-IR ) , proton nuclear magnetic resonance (IH-NMR) , gel permeation chromatography (GPC),thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and so on. No gelation happens in the polymerizations probably because of different reactivities of the amino groups at the 2- and 4-/6- positions in TAP. The results show that the degrees of branching (DB) of the polymers and molecular weights increase when the molar ratios of PMDA :TAP increases from 1 : 1 to 2: 1, but glass transition temperature and 10% weight loss decrease.
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