The Study On The Property And Crystallization Behavior Of Medium Density Polyethylene And Blend Compounds

The property of medium density polyethylene was between HDPE and LDPE. MDPE has not only rigidity but flexibility. It has great predominance on gas pipes, water pipes, coating of cables. So it caused the great attention of the domestic and overseas market. But to the domestic market, people are lack of the cognition of MDPE. The properties and crystallization behaviors of MDPE and MDPE blend compound were studied in this article. And the final aim is to improve the use and the research to MDPE in our country.In this paper, it was proved that the MDPE, compared with other PE, has better balance point of rigidity and flexibility due to its special molecule structure. And it was proved that MDPE can be used as the pipe raw material. The melting and crystallization behaviors of some PE under non-isothermal crystallization conditions were also studied to supply basic theories to the production. It indicated that the non-isothermal crystallization processes of these PE were different. The Mozhishen's method was fit to describe the crystallization process of MDPE and the better linearity relation could be found.In this paper, the mechanical property, rheological property and crystal behavior of MDPE/nano-CaCO₃ compounds were also studied. The result indicates that the mechanics property of MDPE could reach maximum when 3 percent nano-CaCO₃ were introduced to MDPE. The complicated rheological property of the compounds changes the mechanics property, so the producing parameters should be strictly controlled. And pipes made of this compound can satisfy the requirements of...