Praperation And Properties Of Graphene/CaCO₃/PVC Composites

Polyvinyl-chloride(PVC)is one kind of the most popular general resins,but it has the disadvantages like:it's toughness,processing ability and thermal stabilization are very poor.So we must modify PVC in production.In this work,we first compared the toughness of composites which is preparation by light CaCO3?ground CaCO3 or nano-CaCO3 with PVC matrix.We found that the nano-CaCO3 can toughen the PVC better than the other two kinds of CaCO3.Then we use isopropyl tri(dioctylpyrophosphate)titanate to modify the nano-CaCO3 to improve the compatibility and dispersion within the PVC matrix.The result showed that the agglomeration of CaC03 had been reduced after modified and CaCO3 had good compatibility with matrix.The toughness of CaCO3/PVC composite had been improved significantly.The impact strength of the composite is 61.2 kJ·m-2 when the CaCO3 which is modified by 6%modifiers content is 15 phr,improved by 46.1%compared with PVC with unmodified CaCO3 composite.The tensile strength,vicat softening temperature and hardness have no significant change compared with unmodified CaC03 toughening system.Next,we add graphene into the system to improve the thermal stabilization and want to make the composite be thermal conductiveand electric conductive.We made graphene/PVC composite and graphene/CaC03/PVC composite.It was found that the composite without CaCO3 has better thermal stabilization than pure PVC,and the thermal conductivity is 0.1853 W·m-1K-1,improved 44.9%than pure PVC,the electric conductivity is 3.57×10-13 S m-1,but the mechanical property of the composite declined dramatically.The graphene/CaCO3/PVC composite has good impact and tensile properties,and it's thermal conductivity is 0.2536 W m-1K-1 and electric conductivity is 8.92×10-11 S·m-1,both increased than graphene/PVC composite.Finally,it can be summarized that the CaCO3 modified by isopropyl tri(dioctylpyrophosphate)titanate can be dispersed in PVC matrix very well and is compatible with PVC.The composite prepared with PVC and modified CaCO3 has good mechanical property.If we blend PVC with modified CaC03 and graphene through melt blending method,we can get a composite that has good mechanical property,thermal conductivity and electric conductivity.