星型聚己内酯对聚乳酸性能的影响

Effect of Star-shaped Polycaprolactone on Properties of Polylactic Acid

为改进聚乳酸(PLA)的脆性,依据聚合物共混改性原理,合成了一系列星型聚己内酯(PCL)来共混增韧PLA。通过核磁共振氢谱和凝胶渗透色谱表征了合成PCL的结构,采用差示扫描量热分析研究了共混物的热学行为,并通过拉伸试验研究了PCL含量、臂数、臂长对PLA力学性能的影响。结果表明,使用不同多元醇作引发剂合成了不同臂数的星型PCL;加入星型PCL可以改变PLA的结晶性。PLA的力学性能受PCL含量、臂数、臂长影响,当PCL质量分数为10%时,共混膜断裂伸长率达到最高。臂数的增加使拉伸强度和断裂伸长率随之增加,PLA/六臂PCL共混物的断裂伸长率达到197%,拉伸强度达35.9MPa,可以满足多个行业对包装材料的要求。

To overcome the brittleness of polylactic acid(PLA),based on the theory of polymer blending modification,a series of star-shaped polycaprolactone(PCL)were synthesized and used to toughen PLA.The structure of PCL was characterized by nuclear magnetic resonance hydrogen spectrum and gel permeation chromatography,the thermal behavior of the blends was studied by differential scanning calorimetry analysis,and the effects of PCL content,arm number,arm length on PLA mechanical properties were studied by tensile test.The results showed that star PCL of different arm number was synthesized by using different polyols as initiator and the addition of star PCL could change the crystallization of PLA.The mechanical properties of PLA were affected by PCL content,arm number and arm length.When the PCL content was 10%,the elongation at break of blend film reached the highest.The tensile strength and elongation at break increased with the increase of arm number.The elongation at break of PLA/six-arm PCL mixture reached 197%and the tensile strength was 35.9 MPa.The blends can meet the packaging material requirements of multiple industries.