Study On The Preparation And Mechanical Properties Of The Micro-crystal Muscovite/PVC Composites

As a new kind of minerals found in west Sichuan area, the micro-crystal muscovite not only has excellent properties of muscovite group minerals, but also has properties of natural ultra -fine and easy processing, so it has wide expioitation and application prospect in application domains of many polymer materials.In this paper, We mainly studied on the modified conditions when different kinds of the micro-crystal muscovite powder was modified by silane KH-550.The viscosity, FTIR were used to characterized the powder which obtained. The micro-crystal muscovite/PVC composites was prepared by melt-blending process. The micro -structure and properties of such PVC materials were studied by mechanical properties and canning electronic microscope tests. Effect of content of micro-crystal muscovite on mechanical properties of composites were studied also.The results indicate:(1) The powder which were uncalcined and calcined have the best modification when the optimal dosage of KH-550 should be considered at 1.2%～1.4% and 1.4%. The process mainly was a physical cover process after modification.(2) With the content of the micro-crystal muscovite increasing, The tensile strength of composites was decreased firstly and then increased, when the content of the micro-crystal muscovite was 15%, the mechanical properties of composites have good performance, then decreased. For the modified powder which uncalcined, the tensile strength of composites was 71.37MPa, increased by 19.61% compared to pure PVC; For the modified micro-crystal muscovite which calcined, the tensile strength of composites was 73.53MPa, enhanced 23.23% to pure PVC.(3) The impact strength of composites was increased firstly and then decreased also, while the content of the micro-crystal muscovite was increasing. When the content of the micro-crystal muscovite was 10%, the mechanical properties of composites have good performance. For the modified micro-crystal muscovite which uncalcined, the impact strength of composites reachde to 4.28 kJ/m2, enhanced 39% separately compared to pure PVC; For the modified micro-crystal muscovite which calcined, the impact strength of composites was 4.47kJ/m2, enhanced 45.1% to pure PVC.(4) The hardness of composites was increased with the content of the micro-crystal muscovite increasing. while the content of the micro-crystal muscovite was 15%, The hardness of composites was 86.38, enhanceed 5.34% separately compared to pure PVC, the powder which modified and uncalcined; For the modified powder which calcined, the hardness of composites reached to 86.75, increased by 5.79% compared to pure PVC.(5) We found that the modification can effectively improve mechanical properties of the micro-crystal muscovite/PVC composites, but the calcination process was not very obvious. Combination of economic factors, the calcination process can not be adopted.