聚乳酸/醋酸纤维素酯熔融挤出共混物制备及性能研究

A Study on the Preparation and Properties of PLA/CAB Blends

通过双螺杆熔融挤出共混制备得到不同含量比聚乳酸(PLA)/醋酸丁酸纤维素酯(CAB)共混物.采用差示扫描量热仪(DSC)对材料进行了等温和非等温结晶行为研究.发现PLA与CAB为不相容体系,且CAB能有效降低PLA的结晶速率;进一步采用傅里叶红外光谱(FTIR),扫描电镜(SEM)以及热机械分析(TMA)对共混物组分进行了表征测试.结果表明CAB在PLA基体中主要以纳米颗粒状的形式分散,平均尺寸约为160nm,并且CAB在质量含量较高时可形成逾渗网络结构.CAB及其网络结构能够有效抑制PLA链段的运动,从而降低其结晶速率.

The polylactic acid（PLA）/cellulose acetate butyrate（CAB）blends having different weight ratios were prepared by twin-screw extrusion mixing.The isothermal and non-isothermal crystallization behaviors of the polymer blends were studied by differential scanning calorimetry（DSC）.It was found that the PLA is incompatible with CAB and the CAB could inhibit the crystallization of the PLA.Fourier transform infrared spectroscopy（FTIR）,SEM and thermomechanical analysis（TMA）were further applied to study the blends,and found that CAB phase with an average size of 160 nm was dispersed uniformly in the PLA matrix and would form a percolation network when CAB mass fraction is higher than 5%.We think the CAB and its network would obstruct effectively the movement of PLA segments which resulted the lower crystallization speed.