The morphology and mechanical properties of poly（ethylene-octene） copolymers （POE） obtained by dynamic packing injection molding were investigated by mechanical tests, differential scanning calorimetry （DSC）, fo...The morphology and mechanical properties of poly（ethylene-octene） copolymers （POE） obtained by dynamic packing injection molding were investigated by mechanical tests, differential scanning calorimetry （DSC）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. The mechanical tests found that only POE with low octene content and high molecular weight show apparent response for external shear field. Further investigation has been done by DSC, FT-IR, and SEM in order to make clear the reason of that phenomenon. Finally, the hypothetical mechanism of POE microstructure formation under shear field has been proposed. For POE with low octene content and high molecular weight, orientation degree and mechanical properties both increase substantially under shear field. For POE with low octene content and low molecular weight, orientation degree and crystallinity increase under shear field, but it is not dramatically benefit for the mechanical properties. For POE with high octene content and high molecular weight, the shear field has little effect on the morphology and mechanical properties.展开更多
基金supported by the special funds for Major State Basic Research Projects of China (No.2011CB606006)Program for the New-Century Excellent Talents of Ministry of Education of China(NCET-10- 0580)
文摘The morphology and mechanical properties of poly（ethylene-octene） copolymers （POE） obtained by dynamic packing injection molding were investigated by mechanical tests, differential scanning calorimetry （DSC）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. The mechanical tests found that only POE with low octene content and high molecular weight show apparent response for external shear field. Further investigation has been done by DSC, FT-IR, and SEM in order to make clear the reason of that phenomenon. Finally, the hypothetical mechanism of POE microstructure formation under shear field has been proposed. For POE with low octene content and high molecular weight, orientation degree and mechanical properties both increase substantially under shear field. For POE with low octene content and low molecular weight, orientation degree and crystallinity increase under shear field, but it is not dramatically benefit for the mechanical properties. For POE with high octene content and high molecular weight, the shear field has little effect on the morphology and mechanical properties.
