MELT COMPATIBILITY OF METALLOCENE LINEAR LOW-DENSITY POLYETHYLENE AND HIGH-DENSITY POLYETHYLENE BLENDS
文献类型: 外文期刊
作者: Wang Rui 1 ; Yang Qi 1 ; Huang Yajiang 1 ; Li Guangxian 1 ; Wang Jinghui 1 ; Lai Renwu 1 ;
作者机构: 1.Sichuan Univ, Coll Polymer Sci & Engn, State Key Lab Polymer Mat Engn, Chengdu 610065, Peoples R China
2.Chinese Acad Trop Agr Sci, Agr Product Proc Res Inst, Key Lab Trop Crops Proc, Chinese Agr Minist, Zhanjiang 524001, Peoples R China
关键词: Metallocene linear low-density polyethylene;High density polyethylene;Dynamic rheology behavior;Crystallization dynamics;Melt miscibility
期刊名称:ACTA POLYMERICA SINICA ( 影响因子:2.0; 五年影响因子:1.391 )
ISSN: 1000-3304
年卷期: 2010 年 9 期
页码:
收录情况: SCI
摘要: The compatibility between m-LLDPE and two sorts of HDPE with different molecular weights in the melt state was investigated with rheological methods, nonisothermal and isothermal crystallization dynamics. The rheological measurements suggested that HDPE and m-LLDPE blends were heterogeneous systems at 190 degrees C based on the relationship of lgG ' and lg omega) in the low omega region that deviated the linear model. The DSC results showed that with an increase in the content of m-LLDPE, the melting peak of HDPE shifted to lower temperature,suggesting that HDPE and m-LLDPE may be partially compatible. When the blends were cooled from the melt to temperatures where HDPE could crystallize, but the m-LLDPE couldn' t,the Avrami exponent n of high-M(w) HDPE increased slightly compared to that of pure HDPE,and the content of m-LLDPE had little effect on the vales of a. Meanwhile,the crystallization half-time (or crystallization rate) of high-M(w) HDPE was very similar to that of pure HDPE. However, the Avrami exponent and the crystallization rate of the low-M(w) HDPE decreased with an increase in the content of m-LLDPE, indicating that the m-LLDPE retarded crystallization of HDPE,possibly due to the reasons including the dilution of HDPE by m-LLDPE ( m-LLDPE as a solvent in molten state),hindrance of viscous m-LLDPE to the HDPE crystallization front, and decreased supercooling degree because of the compatibility between the m-LLDPE and low-M(w) HDPE. This provided further evidence that the compatibility of the low-M(w) HDPE with m-LLDPE was better than that with the high-M(w) HDPE.
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