挤出吹塑工艺对PBAT/PLA共混体系微观结构与性能的影响

Effect of extrusion blowing process on microstructure and properties of PBAT/PLA blend

通过调控工艺条件(机头温度、牵引速度)熔融共混挤出吹塑聚己二酸/对苯二甲酸丁二醇酯/聚乳酸(PBAT/PLA)原位成纤共混体系薄膜。结果表明,在较低的机头温度时,随着牵引速度的不断增加,分散相PLA在连续相PBAT中原位成纤,且微纤直径逐渐减小,结晶度先增大后下降。挤出吹塑薄膜的纵向拉伸强度和拉伸模量均先增加后减小。在机头温度为150℃、牵引速度为5.0 m/min时,共混体系中PLA成纤效果最明显;薄膜纵向拉伸强度达到40.0 MPa,比纯PBAT提高了20%;拉伸模量达到723.9 MPa,较纯PBAT提升明显。

The in⁃situ fibrillation films based on poly(adipic acid/butylene terephthalate)(PBAT)/poly(lactic acid)(PLA)blends were prepared by extrusion blowing through adjusting the extrusion process conditions such as die temper⁃ature and traction speed.The results indicated that PLA tended to form fibers in PBAT/PLA blend system with an in⁃crease in the traction speed at lower die temperature.The formed fibers tended to refine with an increase at first and then a decrease in the crystallinity.The longitudinal tensile strength and tensile modulus of in⁃situ fiber formed films also in⁃creased at first and then tended to decrease.The effect of PLA in⁃situ fibrillation was the most obvious in the blend at a die temperature of 150℃and a traction speed of 5.0 m/min.Meantime,the longitudinal tensile strength and modulus of the films reached 40.0 and 723.9 MPa,respectively.Their tensile strength was 20%higher than that of pure PBAT,whereas their tensile modulus was much higher than that of pure PBAT.