5405改性双马来酰亚胺树脂基复合材料的湿热老化特性

STUDIES ON WET/HOT AGING CHARACTERISTICS OF 5405 MODIFIED BISMALEIMIDE MATRIX COMPOSTTES

５４０５是针对飞机主受力构件的应用而研制的兼具有韧性、湿热性能和良好工艺性的改性双马来酰亚胺基体树脂。本文报道该树脂浇铸体及其碳纤维复合材料在热、湿作用及热／湿联合作用下的性能变化情况。结果表明，５４０５树脂及复合材料具有优良的湿热老化特性，其水平与Ｎａｒｍｃｏ５２４５Ｃ相当，能确保飞机主受力构件在１３０℃下的使用。

High damage tolerance, excellent wet-hot performance and good processing characteristics are key requirements for composites in primary structure aircraft applications. For this reason, we selected bismaleimide resin systems as an object of study and developed a toughened bismaleimide resin (named 5405) in 1991. Formulations of 5405 resins were obtained by a computer-aided optimization design method. Influence of temperature, wet and wet/hot invironments on the properties of 5405 resin casts and carbon fiber resinforced composites T300/5405 was reported on this paper. Importmant experimental results are as follows:(1):Residual percentage of 5405 resin casts was 77%, at 130 ℃ for tensile strength and 72.2% at 132 ℃ for flexural strength respectively. For all kinds of essential mechanical properties of T300/5405 composites, the residual percentages at 130 ℃ were above 60%. These data show that 5405 has the same anti temperature level as Narmco 5f245C which was developed during 1980' s for aircraft primary structure application by Narmco Materials, Inc.(2)5405 resin casts and T300/5405 composites have lower moisture absorption than many other bismaleimide resins such as 5245C, K601, M751 and H795.(3)Initial thermal decomposition temperature, heat resistant index and thermal decomoposition activation energy of 5405 resin casts were 372 ℃, 202 ℃ and 112. 2 kJ/mol respectively.Mechanical properties of T300/5105 composites at room temperature or at 130 ℃ had no great changes after heat aging of 150 ℃/1000h.These show that 5405 resin has good stability.(4)Residual percentage of T300/5405 coomposites under wet-hot condition (40 h immersion in boiling water and at 130 ℃) was 49. 5% for intralaminar shear strength and 60% for L-T shear strength respectively which are same as those of IM-6/5245C.From above results, it is concluded that 5405 resin has good wet-hot aging characteristics which are equal to Narmco 5245C,and it could use as aircraft primary structure at 130℃.