快速拉挤用环氧树脂体系TTT图构建及应用

Construction and Application of TTT Diagram of Epoxy Resin System for Rapid Pultrusion

拉挤成型复合材料由于其质量轻、强度高、生产成本低等优点被广泛应用。拉挤成型用树脂基体是影响复合材料工艺和性能的关键因素,掌握其在成型固化过程中的凝胶化和玻璃化行为对工艺制定和提高复合材料性能具有重要意义。文中制备了快速拉挤成型环氧树脂基体,采用动态差示扫描量热仪(DSC)和半经验的唯象模型研究了树脂固化度和固化时间、温度之间的关系,绘制了等固化度曲线;采用恒温DSC得到了基于DiBenedetto经验方程的玻璃化转变曲线;通过测试树脂的凝胶点,研究了凝胶时间和温度的关系。综合上述工作绘制了拉挤树脂体系的TTT(Time-Temperature-Transition)图,由TTT图确定了拉挤速度及模具温度设置。依据确定的工艺参数制备了拉挤板材,经超声扫描和DSC测试,复合材料内部无空隙,玻璃化转变温度达到了树脂完全固化水平。

Pultrusion composites are widely used because of their advantages of light weight,high strength and low production cost.The resin matrix used in pultrusion molding is the key factor affecting the process and properties of the composites.It is of great significance to master the gelation and glass transition behavior of the resin matrix in the process of molding and curing for making the technology and improving the performance of the composites.A dynamic differential scanning calorimetery(DSC)and a semi-empirical phenomenological model were used to study the relationship between curing degree,time and temperature of pultruding resin,and the isoconversion line was drawn.Then,the glass transition curve based on DiBenedetto empirical equation was obtained by DSC.Moreover,by testing the gel point of resin,the relationship between gel time and temperature was studied.Based on the above work,the TTT(time-temperature-transition)diagram of the pultrusion resin system was drawn,which detemined the pultrusion speed and mold temperature settings.Based on the determined process parameters,the pultruded plates were prepared.Through ultrasonic scanning and DSC testing,it was found that there were no voids inside the composite materials,and the glass transition temperature reached the level of complete resin curing.