不同分子量PCL/PLLA共混物的结晶行为研究

Crystallization Behavior of PCL/PLLA Blends with Different Molecular Weight

为了研究不同分子量PCL/PLLA共混物结晶行为,文中以二氯甲烷为溶剂对左旋聚乳酸(PLLA)与聚己内酯(PCL)进行溶液共混,制备不同质量比的PCL/PLLA共混物,并利用热台偏光显微镜(POM)和差示扫描量热仪(DSC)对共混物的结晶行为及结晶形貌进行表征与分析。实验结果表明:在PLLA10k中加入PCL2k和PCL10k,PCL的质量分数为10%~20%时对PLLA10k的结晶能力有促进作用;PCL2k/PLLA25k共混物中,随着PCL2k质量分数的增大,促进作用逐渐减小;加入PCL15k后对PLLA25k的结晶能力没有促进作用。POM结果表明,加入PCL后共混物的结晶速率降低,PCL不利于PLLA球晶生长速率的提高,并且PCL10k与PLLA10k共混时会发生宏观的相分离现象。

The paper studies the crystallization behavior of PCL/PLLA blends with different molecular weights.The PCL/PLLA blends with different mass ratios were prepared with dichloromethane as the solvent.Their crystallization behavior and crystal morphology were characterized by using a hot stage polarizing microscope (POM) and a differential scanning calorimeter (DSC).The experimental results show that adding PCL2k and PCL10k to PLLA10k can improve the crystallization ability of PLLA10k when the mass fraction of PCL is 10%~20%.In PCL2k/PLLA25k blends,the accelerating effect decreases gradually with the increase of PCL2k mass fraction.The addition of PCL15k can not promote the crystallization ability of PLLA25k.The POM result shows that the crystallization rate of the blends decreases after adding PCL,indicating that PCL is not conducive to the increase of PLLA’s spherulite growth rate.In addition,macro phase separation occurred when PCL10k was blended with PLLA10k.