湿法缠绕苯并噁嗪/碳纤维复合材料的性能

分析了3种环氧树脂改性苯并噁嗪(BZ)树脂固化体系的黏温特性、凝胶时间、浇铸体力学性能等,从而优选出一种适用于湿法缠绕且具有优异性能的树脂体系,其由100份BZ树脂预聚体,10份混合环氧树脂,5份芳香胺类固化剂组成。以该树脂体系为基体,利用湿法缠绕工艺制备了NOL环,探究了缠绕张力对NOL环力学性能的影响;在较优缠绕张力下,制备了内径150mm标准压力容器,并进行了相关性能测试。结果表明,优选的树脂体系具有优异的黏温特性,适用期超过8h,浇铸体具有较好的力学性能(如拉伸强度达到78MPa,拉伸弹性模量达到4.56GPa),拉伸断裂面出现些许韧窝;随着缠绕张力的增大,NOL环的拉伸及层间剪切强度先增大后减小,当缠绕张力为10N时,拉伸强度达到2 680MPa,层间剪切强度达到66MPa,且高温条件下(160℃),拉伸与层间剪切强度保持率均超过85%;在较优缠绕张力(10N)下,压力容器的特征系数为41.3km,纤维强度转化率达到89.1%,基本发挥了碳纤维的力学性能。

Study on Properties of Wet Winding Benzoxazine/Carbon Fiber Composites

The viscosity temperature characteristics,gel time,casting mechanical properties of three epoxy resin modified benzoxazine resin curing systems were analyzed,and a resin system suitable for wet winding and excellent performances was selected,which consists of 100 phr benzoxazine resin prepolymer,10 phr mixed epoxy resin and 5 phr aromatic amine curing agent.NOL rings were prepared with the selected resin system as the matrix by wet winding process,the effects of winding tension on the mechanical properties of NOL rings were investigated.Under optimum winding tension,standard pressure vessel with 150 mm of internal diameter was prepared and its mechanical properties were tested.The results show that the selected resin system has excellent viscous-temperature properties,its application life is over 8 hours,the mechanical properties of the casting are good(such as the tensile strength is 78 MPa,the tensile modulus is 4.56 GPa),and some dimples appear on the tensile fracture surface.With the increase of winding tension,the tensile/interlaminar shear strength of NOL ring first increases and then decreases,when the winding tension is 10 N,the tensile strength reaches 2 680 MPa and the interlaminar shear strength reaches 66 MPa,and the retention rates of tensile/interlaminar shear strength all exceed 85%at high temperature(160℃).Under the optimum winding tension(10 N),the characteristic coefficient of the pressure vessel is 41.3 km,and the conversion rate of fiber strength reaches 89.1%,which indicated the mechanical properties of carbon fibers are basically developed.