含芳基均三嗪环耐高温低聚酰亚胺的合成与性能

通过调控聚合单体的摩尔配比,合成了一系列新型的不同分子链长度的邻苯二甲腈封端含二氮杂萘酮联苯结构低聚酰亚胺,通过FTIR、1H-NMR、WAXD和元素分析对其结构进行表征.以4,4′-二氨基二苯砜为催化剂,低聚物经常压下固化交联后,得到含芳基均三嗪环结构的热固性聚酰亚胺.低聚物表现了良好的溶解性能,可溶于N-甲基-2-...

HEAT-RESISTANT OLIGO (PHTHALAZINONE IMIDE) S CONTAINING ARYL-S-TRIAZINE IN THE MAIN CHAIN

A novel series of soluble and curable phthalonitrile-terminated oligo(phthalazinone imide)s with well controlled molecular weights were prepared by varying the molar ratio of dianhydrides to diamines.FTIR,1H-NMR and elemental analysis were applied to confirm the structures of the oligomers whose molecular weights were determined by 1H-NMR analysis.The crosslinking reactions of the phthalonitrile-terminated oligomers were performed under normal pressure in the presence of 4,4′-diaminodiphenylsulfone as catalyst at elevated temperatures to form the s-triazine rings-containing thermosetting oligo(phthalazinone imide)s.The oligomers possess good solubility in common aprotic solvents such as chloroform,pyridine,m-cresol and N-methyl-2-pyrrolidone due to the incorporation of crank,twisted and non-coplanar phthalazinone moiety into the polymer main chain,which disorders the close packing of the intermolecular chain.However,the cured samples are insoluble in all solvents because of the formation of the heterocyclic s-triazine networks during the crosslinking reaction of the cyano groups.The thermal properties of both the oligomers and the cured oligoimides were characterized by DSC,TGA and DTG.The oligomers have high glass transition temperatures(Tgs) in the range of 200～249℃.The cured samples show no Tg from 100～400℃ for the heterocyclic s-triazine networks decrease the flexibility of polymer backbone.And they exhibit excellent thermal stability with 5% weight loss temperature up to 522～532℃,10% weight loss temperature ranging from 556℃ to 567℃ and the carbonized residue values at 800℃ in the range of 69%～74%.For the excellent thermal stability of the cured oligoimides,they can be used as high performance polymeric materials in the aerospace and base materials for high temperature composite matrix.