Effect of Solid-state Stress Induced Reaction on Morphology and Structure of Metallocene Polyethylene
writer：Huawei Zou*, Yang Chen, Mei Liang, Pengbo Liu
keywords：polyolefins，properties and characterization，morphology
source：期刊
specific source：Journal of Applied Polymer Science, 2013, 130(3):1691-1699
Issue time：2013年
Metallocene-catalyzed polyethylene (mPE)
powder was prepared through a mechanochemical reactor in solid state at ambient
temperature. The changes of morphology and structure of mPE were investigated
by SEM, FTIR, DSC, viscosimetry, GPC, WAXD, dynamic rheometer, and high
pressure capillary rheometer methods. FTIR measurement illustrated that the
branching degree of mPE increased after mechanochemical reaction. Combined with
the dynamic rheological analysis, it was proved that the rupture and
combination of macromolecular chain undergo strong shear resulted in the
formation of long chain branches. X-ray diffraction analysis showed that the
crystal form of mPE transferred from rhombic to monoclinic system partly, and
the crystalline degree increased slightly in the initial mechanochemical
reaction period. Viscometer test results exhibited that molecular weight of mPE
dropped during the mechanochemical treatment. Rheology measurement indicated
that the critical shear rate of the shark-skin failure enhanced and the
extruded stands exhibited smooth face for the mPE after mechanochemical
treatment.