THE CHANGES OF MELT FLOW BEHAVIOUR OF PE FILM DURING THE INITIAL STAGE OF WEATHERING
聚乙烯薄膜在大气曝露初期熔体流动行为变化的研究

The changes in the structure and properties of PE film during the process of weathering were studied. It was observed that the chemical reaction occuring in the polymer during short time exposure to weather could be sensitively detected and monitored by MFI (melt flow index) measurement and trace carbonyl analysis.It is concluded that the change of MFI in PE film during the initial stage of weathering is not a direct result of changes in polymer structure or rather a reflection, of cross-linking in the polymer taking place during MFI measurement,which is enhan-ced by the trace active species produced in the early hotochemical reaction.