基于响应曲面法的木塑复合材料强度分析及挤出工艺优化

Strength analysis and extrusion process optimization of wood-plastic composite by response surface method

以杨木纤维(WF)为增强材料,以高密度聚乙烯(HDPE)为基体,马来酸酐接枝聚乙烯(MAPE)为偶联剂,采用熔融挤出法制备了WF/HDPE复合材料。选取WF含量、偶联剂添加量、挤出温度为自变量,试件的抗冲击强度、弯曲强度、拉伸强度为响应值,采用Box-Behnken Design方法设计实验并利用响应曲面法建立WF/HDPE复合材料力学强度的二次多项数学模型,对WF/HDPE复合材料的挤出工艺进行优化设计。结果表明,WF添加量、MAPE添加量和挤出温度的最佳水平为:47.37wt%、4.23wt%、173.69℃,此时WF/HDPE复合材料的抗冲击强度为4.06 kJ·m^(-2),弯曲强度为43.79 MPa,拉伸强度为28.59 MPa。模型预测值与实测值误差小于5%,较好地反映了WF/HDPE复合材料力学性能与挤出工艺因素间的关系。

WF/HDPE composites were prepared by melt extrusion with poplar fiber(WF) as reinforcing material,high density polyethylene(HDPE) as matrix and maleic anhydride grafted polyethylene(MAPE) as coupling agent.The addition amount of WF, the addition amount of coupling agent and the extrusion temperature were selected as independent variables, and the impact strength, bending strength and tensile strength of the specimen were selected as the response value. The experiment was designed by Box-Behnken Design method and the secondary mathematical model of mechanical strength of WF/HDPE composites was established by the response surface method to optimize the extrusion process of the composites. The results show that the optimum levels of WF addition, MAPE addition and extrusion temperature are 47.37 wt%, 4.23 wt% and 173.69℃, respectively. The corresponding impact strength, bending strength and tensile strength of WF/HDPE composite are 4.06 kJ·m^(-2), 43.79 MPa and28.59 MPa. The error between the predicted value of the model and the measured value is less than 5%, which well reflects the relationship between the mechanical properties and the factors of extrusion process of the WF/HDPEcomposites.