Wu Chia-Yang, Lui Wai-Bun, Peng Jinchyau
Department of Bio-Industrial Mechatronics Engineering, National Chung Hsing University, Taichung 402, Taiwan.
Department of English, National Pei-Kang Agricultural and Industrial Vocational High School, Yunlin 651, Taiwan.
Polymers (Basel). 2018 Jul 26;10(8):827. doi: 10.3390/polym10080827.
Poly(3-hyroxybutyrate--3-hydroxyvalerate) (PHBV), poly(vinyl acetate) (PVAc), and tapioca starch are environment-friendly materials. The present study used these materials to produce biodegradable plastic pellets by melt extrusion. The tapioca starch content of composite formulations, the maleic anhydride content, and the screw speed of the extruder were chosen as variables for the extrusion process. A Box-Behnken response surface design was used to establish mathematical models to predict the relationship between the operating variables and the objective attributes (tensile strength, elongation at break, and water absorption) of the blends. Blend morphology was also assessed. The regression coefficients revealed that the extrusion parameters most significantly affecting extrudate responses were tapioca starch content and maleic anhydride content, both showing significant ( < 0.01) linear effects. The results of the analysis of variance found the models are in good agreement with experimental results as informed by high correlation coefficients (² > 0.9), with no significant lack of fit. From the numerical analysis, optimized operating variables (20.13% tapioca starch content, 10.14% maleic anhydride content, and a screw speed of 41.3 rpm) produced a product with optimum values of 16.4 MPa tensile strength, 13.2% elongation at break, and 30.94% water absorption.
聚（3-羟基丁酸酯-3-羟基戊酸酯）（PHBV）、聚醋酸乙烯酯（PVAc）和木薯淀粉都是环保材料。本研究使用这些材料通过熔融挤出生产可生物降解的塑料颗粒。复合配方中的木薯淀粉含量、马来酸酐含量和挤出机的螺杆转速被选为挤出过程的变量。采用Box-Behnken响应面设计建立数学模型，以预测操作变量与共混物的目标属性（拉伸强度、断裂伸长率和吸水率）之间的关系。还对共混物形态进行了评估。回归系数表明，对挤出物响应影响最显著的挤出参数是木薯淀粉含量和马来酸酐含量，两者均显示出显著（<0.01）的线性效应。方差分析结果表明，模型与实验结果高度吻合，相关系数较高（²>0.9），不存在显著的失拟现象。通过数值分析，优化的操作变量（木薯淀粉含量20.13%、马来酸酐含量10.14%和螺杆转速41.3 rpm）生产出的产品具有最佳值，拉伸强度为16.4 MPa、断裂伸长率为13.2%、吸水率为30.94%。
