INTERFACIAL ADHESION AND MECHANICAL PROPERTIES OF PMMA-COATED CaCO_3 NANOPARTICLE REINFORCED PVC COMPOSITES

摘要

Polymethyl methacrylate (PMMA)-coated nano-CaCO_3 particles were prepared by in-situ emulsion polymerization. The mechanical properties of nano-CaCO_3 particles-reinforced PVC were investigated using an AG-2000A universal testing machine and an XJU-2.75 izod impact tester; interfacial adhesion between CaCO_3 nanoparticles and PVC matrix by SEM, and structure of PMMA coated on the surface of CaCO_3 by FTIR and ~1H-NMR. The results indicate that the PMMA coated on the nano CaCO_3 particles consists mainly of syndiotactic structure, and their three tacticity contents were rr 52.8%, mm 7.3% and mr 39.9%, respectively. The interfacial adhesion between CaCO_3 nanoparticles and PVC matrix was significantly improved when the CaCO_3 nanoparticles were coated with PMMA, which led to increased Young's moduli and tensile strengths of the PMMA-coated CaCO_3/PVC composites. The izod impact strengths of the composites were strongly affected by the PMMA coating thickness and increased significantly with increasing the volume fraction of CaCO_3 filler in the composites.