The Roles of Polyacrylate in Poly(vinyl chloride)-Lignin Composites

A novel method was adopted to improve the adhesion between lignin particles and poly(vinyl chloride) (PVC) matrix in PVC-lignin composites. Lignin was treated with a polyacrylate, poly(ethyl acrylate-co-acrylic acid), and the composites was prepared with PVC and the treated lignin. The mechanical properties and morphology of the composites were investigated, and the roles of polyacrylate in the composites were discussed. The results show that both the tensile and impact strengths of the composites are improved when both the content of carboxyl in polyacrylate and its dosage are low, and the optimum is: yield strength, 24.17 MPa, higher than that of PVC control (21.88 MPa); breaking strength, 33.59 MPa, close to that of PVC control (35.62 MPa); and impact strength, 8.0 kJ m(-2), 31% higher than that of PVC control (6.1 kJ m(-2)). Microscopic morphology analysis suggests that polyacrylate improved the adhesion between lignin particles and PVC matrix. The roles of polyacrylate are as the following: polyacrylate is combined with lignin by hydrogen bond and ester bond, and most of its chains spread into PVC matrix due to its good compatibility with PVC, thereby lignin particles can be well bound with PVC matrix. POLYM. COMPOS., 32: 1399-1407, 2011. (C) 2011 Society of Plastics Engineers