RTM用双马来酰亚胺树脂及其复合材料的制备与性能研究

STUDY ON PREPARATION AND PROPERTIES OF BISMALEIMIDE RESIN FOR RTM AND ITS COMPOSITES

采用一种含醚键双马单体对双马来酰亚胺树脂进行改性,制备了一种适用于复合材料树脂转移模塑成型工艺(RTM)的高韧性双马来酰亚胺树脂基体,并研究了其流变特性、耐热性能、力学性能及其复合材料的力学性能。树脂体系的流变性能数据表明树脂在注射温度(100℃)下具有较长的适用期(~3 h),能够满足RTM成型的要求。树脂浇注体的拉伸强度为115 MPa,断裂延伸率为3.1%,弯曲强度为159 MPa,玻璃化转变温度为270℃,表明树脂具有较高的韧性和耐温等级。以本树脂体系作为基体制备得到的碳纤维增强复合材料具有较高的力学性能,同时在230℃下具有较高的力学性能保持率。

The bismaleimide（ BMI） resin,owing to its excellent thermal-oxidative stability and outstanding mechanical properties,has been successfully used for aerospace structure composites. The obvious shortcoming of the BMI resin is brittleness,therefore its application is limited. Resin transfer molding（ RTM） process is suitable for the production of large,complex,thick-sectioned structures,which provides good surface quality and increases the parts integration. Traditional toughening methods such as thermoplastic toughening are not suitable for resin for RTM process due to viscosity increase. A kind of novel toughened bismaleimide resin for RTM was fabricated by introducing of an internal chain extension monomer,which presented good processability,such as low viscosity,long pot time（ ～ 3 h） and high toughness. The mechanical properties were characterized and indicated that the tensile strength and elongation was 115 MPa and 3. 1%,respectively. The flexural strength was 159 MPa. The glass transition temperature of the cured resin was 270 ℃,characterized by DMA. Composites were prepared from carbon fiber and the BMI resin,which exhibited excellent mechanical properties and high retention rate at 230 ℃.