Effect of glycerol content on the properties of starch/polylactic acid composite

Starch/polylactic acid composites were prepared by melt extrusion method with corn starch and polylactic acid as raw material,glycerol as the plasticizer.Melt fluidity,interfacial compatibility,mechanical properties,water absorption rate and rheological properties of composite was studied by glycerol content.The results show that the increased glycerol content was increased melt flow properties of composite materials,and reduce the complex viscosity,which helps to improve the processing performance of the composite material. The addition of glycerol increased the interface compatibility between starch and polylactic acid,and with glycerol content increased,the compatibility was improved more.Compatibility improve was increased the tensile strength of the composite.Plasticizer can damage the crystalline structure of starch,reduce the interaction of molecules,and so increase flexibility of composite material.Thus,with glycerol dosage increase,the bending strength and storage modulus were decreased,but the elongation at break increased.Water absorption test results show that increased glycerol dosage was help to improve the water resistance of composite materials.