纳米氧化锌的改性及其对生物高分子P(3HB-co-4HB)的增韧增强作用

Toughening and reinforcing effects of modified nano-ZnO on biopolymer poly(3-HB-co-4-HB)

为提高生物高分子聚（3羟基丁酸脂-co-4羟基丁酸脂）[P（3HB-co-4HB）]的韧性和刚性,细化球晶尺寸,通过熔融共混法制备了以P（3HB-co-4HB）为原料、钛酸酯偶联剂（TMC-980）改性纳米氧化锌（nano-ZnO）为增强剂的 P（3HB-co-4HB）/nano-ZnO复合材料.采用动态接触角测量仪、激光粒度仪、扫描电子显微镜（SEM）、偏光显微镜（POM）和电子万能试验机等分别研究 nano-ZnO 的表面改性效果、改性nano-ZnO 对复合材料力学性能、冲击断面形貌和结晶形貌的影响.结果表明,改性 nano-ZnO 的粒径从5．19×10^4 nm降至1．56×10^2nm；水接触角从7°提高到58°.改性 nano-ZnO 质量分数为1％～1．5％时,P（3HB-co-4HB）/nano-ZnO 复合材料的缺口冲击强度、拉伸强度和断裂伸长率分别较纯 P（3HB-co-4HB）提高30．2％,11．2％和67．6％.改性nano-ZnO 可作为成核剂有效减小复合材料的球晶尺寸,使其断面形貌呈现典型韧性断裂特征.

Poly（3-Hydroxybutyrate-co-4-Hydroxybutyrate）[P（3HB-co-4HB）]and nano-ZnO modified by titan-ate coupling agent （TMC-980）were selected as substrate and reinforcing agent respectively to prepare poly （3 HB-co-4 HB）/nano-ZnO composites via melt blending in order to improve its roughness and stiffness,refine its spherulitic size.Dynamic Contact Angle Measurer,Laser Particle Size Analyzer,SEM,POM and Universal Testing Instrument etc.were used to characterize the effect of surfacial modification of nano-ZnO,the effects of modified nano-ZnO on the mechanical properties,fracture morphologies and crystallization morphologies of composites.The results show that the particle size of modified nano-ZnO decreased from 5.19×10^4nm to 1.56×10^2nm.The water contact angle of modified nano-ZnO increased from 7 to 58°.The notched impact strength, tensile strength and break elongation of P（3HB-co-4HB）/nano-ZnO composites are higher 30.2%,11.2% and 67.6% than that of neat P（3HB-co-4HB）respectively at mass fraction 1%-1.5% of nano-ZnO.Acting as nu-cleating agent,modified nano-ZnO can significantly decrease the spherulite size of the composites and make it to be typical ductile fracture characteristics.