工艺条件对PBAT/PLA原位成纤共混体系结构与性能的影响

Effect of processing conditions on structure and properties of PBAT/PLA in⁃situ fibrillation blends

将质量比为80/20的PBAT/PLA共混物在单螺杆挤出流延成型机中通过调控工艺条件(口模温度、拉伸速度)直接熔融共混制备PBAT/PLA原位成纤共混薄膜。结果表明,在较低口模温度时,随着拉伸速度的提高,PLA微纤细化程度加大,结晶度先提高后降低,纵向拉伸强度先增加后减小,力学性能各向异性明显。在口模温度为150℃、拉伸速度为5.0 m/min时,共混体系中PLA成纤效果最明显;PBAT和PLA的结晶度最高分别为4.8%和23.7%;纵向拉伸强度达到29.8 MPa,比纯PBAT提高了41%。

Poly(butylene adipate terephthalate)(PBAT)/poly(lactic acid)(PLA)(PBAT/PLA,80/20)in⁃situ fibrilla⁃tion blends were prepared by a single⁃screw melt⁃extrusion casting machine under various die temperature and stretching speed.The results indicated that at lower die temperature,with the increase of stretching speed,the diameter of PLA microfibers dwindles,the crystallinity degree enhance first and then lowers,the longitudinal tensile strength increases first and then decreases,and the mechanical anisotropy is obvious.When the die temperature was 150℃and the stretch⁃ing speed was 5.0 m/min,the number of dispersed phase PLA microfibers grow;the highest crystallinity of PBAT and PLA are 4.8%and 23.7%,respectively;the longitudinal tensile strength reaches the maximum of 29.8 MPa,which is at least 41%higher than that of pure PBAT.