改性双马来酰亚胺树脂体系的催化

On Developing Good Heat-Resistant Bismaleimide Using Low-Temperature Cure

改性双马来酰亚胺树脂体系的催化顾媛娟，梁国正，蓝立文，郑修麟改性双马来酰亚胺（ＢＭＩ）作为先进复合材料树脂基体已在航空、航天等高技术领域得到了广泛的应用，但它的高后处理温度（通常在２２０～２５０℃）极大地限制了其在民用工业中，尤其是制造大型构件方面的...

This summary reports research results of our project funded by a P. R. C. research institute. The aim of our project is, while retaining good heat- resistant properties, to lower curing and postcuring temperatures (postcuring temperature up to now is as high as 220-250 C in China) and shorten cure cycle of modified bismaleimide (BMI) resins so as to meet urgent need in China.In this summary,BMI/APC (allyl phenyl compounds) was chosen as the base resin,and many catalytic systems were tried to improve the reactivity of the base resin. Experimental findings are:(1)The conditions under which catalyzed BMI/APC resin can be cured and postcured at low temperature, without lowering excellent thermal and mecha-meal properties, are: thecatalytic system only catalyzes the copolymerization of BMI and APC but does not speed up their self- polymerizations.(2) The optimum range of catalytic syStem is 0. 5 %--1 %. For reasons please see (6).(3) As shown in Fig. 1, the temperature of starting of polymerization (Ts), the temperature of exothermic peak position (Ts), and the temperature of termination of polymerization (Ts) are all 70-90℃ lower than those of the uncatalyzed base resin, while the pot life at the room temperature of the former is still more than 3 months. These good results arereached after much research on suitable reactivity.(4) After cUTing at the temperature lower than 180℃ and postcured at the temperaturelower than 200℃, the properties of the catalyzed resin are: heat deflection temperature = 290 ℃, glass transition temperature = 317 ℃, fiexural strength ≥110 MPa, tensilestrength≥70 MPa, impact strength ≥9kJ/m2.(5) The properties of the neat catalytic resin can be fully retained by the composites based on the resin.After curing and postcuring at the temperature of lower than 180 200℃,successively,the T300 carbon fiber reinforced composites have good thermal and mechanical properties. When tested at 230℃,the short beam shear strength is 52 MPa and 51 % of the original room temperature strength is retained.(6) Quantity of catalytic syrstem has great effect on thermal and mechanical properties of the neat resin.The more the quantity of catalylic system is,the higher is the reactivity of the resin,the better, the heat-resistance, the higher,the fie-cural and tensile strengths,butthe lower is the impact strength of the neat resin'