摘要
采用两步法合成了两个系列侧链含新型偶氮三嗪染料发色团的共聚聚酰亚胺 OPI( x)和 PPI( x) .用红外光谱、紫外 -可见光谱、 DSC和 TGA等手段对其进行表征 .它们均溶于强极性非质子溶剂 ,如 NMP,DMAc,DMF,DMSO和 1 ,4 -丁内酯等 .其截止吸收波长小于 50 0 nm,在大于 50 0 nm波长范围内基本透明 .这些共聚物的特性粘数在 0 .2 5～ 0 .50 d L/g范围内 .它们都表现出较高的玻璃化转变温度 ( Tg) .以刚性相对较大的均苯四甲酸二酐 ( PMDA)为二酐单体的 PPI( x)的 Tg 在 573 K左右 ;以二苯醚 -3 ,3′,4 ,4′-四甲酸二酐 ( OPDA)为单体的 OPI( x)的 Tg在 53 3～ 543 K之间 ,且基本与染料发色团含量无关 .所有的共聚聚酰亚胺都表现出优良的高温稳定性 ,其 5%热失重温度比相应聚合物的 Tg高 1 0 0
Two series of copolyimides, OPI( x ) and PPI( x ), containing a triazine azo chromophore were prepared by a two step process, which includes a solution polycondensation followed by a chemical imidization. The copolyimides obtained were characterized by FTIR spectroscopy, UV Vis spectroscopy, DSC and TGA. The obtained copolyimides are soluble in aprotic organic solvents such as N methyl 2 pyrrolidone(NMP), N,N dimethyl acetamide(DMAc), N,N dimethyl formamide(DMF), dimethylsulfone (DMSO) and 1,4 butyrolactone. They are almost completely transparent at wavelengths greater than 500 nm. The intrinsic viscosities of OPI( x ) and PPI( x ) are in the range 0.25—0.50 dL/g. All copolyimides possess high T g and thermal stability. T gs are about 573 K for copolyimides based on pyromellitic dianhydride(PMDA) and 533—543 K for those based on 3,3′,4,4′ diphenylethertetra\|carboxylic dianhydride(OPDA) and are almost independent of the chromophore loading level. The 5% weight loss temperatures of the copolyimides are more than 100 K higher than the corresponding T gs and this high thermal stability would ensure high temperature poling of the copolyimides. [WT5HZ]
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第12期1944-1947,共4页
Chemical Journal of Chinese Universities
基金
上海市科委新材料研究中心重点基金!(批准号 :97JC14 0 14 )
上海交通大学青年基金资助
