摘要
采用“柔顺性”二胺单体４，４＇－二（４－氨基苯氧基）二苯砜与二氨基二苯砜及二苯甲酮四甲酸酐进行共缩聚并在高温溶液亚胺化合成了可溶于ＮＭＰ、ＤＭＡｃ、ＤＭＦ等强极性溶剂的可溶性聚酰亚胺，并发现在本研究体系中，单纯提高分子链柔顺性并不能很好地提高ＰＩ的可溶性，必须结合共缩聚方法以破坏分子链规整性，所得ＰＩ只有在４，４’－二（４－氨基苯氧基）二苯砜与二氨基二苯砜的摩尔比在３：７～６：４时才可溶。所得可溶性ＰＩ的特性粘度为０．２１～０．３８ｄｌ／ｇ（ＮＭＰ为溶剂，Ｔ＝３０℃），以ＤＳＣ测得的玻璃化转变温度在２５０～２９０℃，氮气中热分解温度在５００℃以上。
Soluble polyimides were prepared by a co-condensation of a“flexible”diamine monomer, bis [4-(4-aminophenoxy) phenyl] sulfone with another diamine.4,4’-diamino diphenyl sulfone and a dianhydride,3,3' ,4,4'-benzophenonetetracarboxylic acid dianhydride followed by the solution imidation at high temperature.Polyimides obtained are soluble, in strong polar solvents, such as NMP,DMAc and DMF.It、was observed that, in the system studied, the solubility of polyimides can not be achieved simply by the increase of the flexibility of the molecular chains resulted from the introduction of a“flexible”diamine, the reduction of the regularity of the molecular chains,which can be achieved through co-condensation is also required. The soluble polyimides obtained have intrinsic viscosities between 0. 21～0. 38dL/g (in NMP, 30℃ ). The glass transition temperatures of polyimide samples measured by DSC were observed to be 250～290℃ and the thermal decomposition temperatures in N2 were above 500℃.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
1996年第2期38-42,共5页
Polymer Materials Science & Engineering
