Melt blends of low-density polyethylene(LDPE), ethylene vinyl acetate(EVA) and coal with various compositions were prepared through reactive extrusion. The rheological behaviour was studied with respect to the effect ...Melt blends of low-density polyethylene(LDPE), ethylene vinyl acetate(EVA) and coal with various compositions were prepared through reactive extrusion. The rheological behaviour was studied with respect to the effect of blend ratio, shear rate using a rheometer to gain an understanding of processing parameters controlling industrial ap-plication. Compatibility was also evaluated by differential scanning calorimetry(DSC) and scanning electron microscopy(SEM). The results revealed that LDPE/EVA/coal is a partly compatible system showing pseudo-plastic behaviour, increase in viscosity with increased coal content appeares evident only at low shear rate region, viscosity tends to keep consistent approximately but irrelates to coal content at higher shear rate. Blends viscosity and compatibility are attibuted to changes in LDPE crystalline structure and entanglement, together with interaction between macromolecular aliphatic chains in coal and amorphous phase in LDPE and EVA at the boundaries of phases, which comes forth during the rear-rangement process of the crystalline structure.展开更多
Poly(ethylene-co-vinylacetate)/sodium montmorillonite(EVA/MMT)and Poly(ethylene-co-vinylacetate)/organophilic montmorillonite(EVA/o-MMT)nanocomposite were prepared by solid-state mixing.The morphology and structure of...Poly(ethylene-co-vinylacetate)/sodium montmorillonite(EVA/MMT)and Poly(ethylene-co-vinylacetate)/organophilic montmorillonite(EVA/o-MMT)nanocomposite were prepared by solid-state mixing.The morphology and structure of the composites were explored by scanning electron microscopy(SEM),wide-angle X-ray diffraction(WAXD),differential scanning calorimetry(DSC),and dynamic mechanical analysis(DMA).The results showed that the intercalated nanocomposite was successfully synthesized for EVA/o-MMT system,while in the EVA/MMT nanocomposite,MMT were poorly dispersed in the order of μm.An unexpected rubbery plateau modulus of EVA/o-MMT nanocomposite above melting point of EVA was explored by DMA.The possible origins of this high-temperature modulus were analyzed.展开更多
基金Supported by the National Nature Science Foundation(20276056)
文摘Melt blends of low-density polyethylene(LDPE), ethylene vinyl acetate(EVA) and coal with various compositions were prepared through reactive extrusion. The rheological behaviour was studied with respect to the effect of blend ratio, shear rate using a rheometer to gain an understanding of processing parameters controlling industrial ap-plication. Compatibility was also evaluated by differential scanning calorimetry(DSC) and scanning electron microscopy(SEM). The results revealed that LDPE/EVA/coal is a partly compatible system showing pseudo-plastic behaviour, increase in viscosity with increased coal content appeares evident only at low shear rate region, viscosity tends to keep consistent approximately but irrelates to coal content at higher shear rate. Blends viscosity and compatibility are attibuted to changes in LDPE crystalline structure and entanglement, together with interaction between macromolecular aliphatic chains in coal and amorphous phase in LDPE and EVA at the boundaries of phases, which comes forth during the rear-rangement process of the crystalline structure.
文摘Poly(ethylene-co-vinylacetate)/sodium montmorillonite(EVA/MMT)and Poly(ethylene-co-vinylacetate)/organophilic montmorillonite(EVA/o-MMT)nanocomposite were prepared by solid-state mixing.The morphology and structure of the composites were explored by scanning electron microscopy(SEM),wide-angle X-ray diffraction(WAXD),differential scanning calorimetry(DSC),and dynamic mechanical analysis(DMA).The results showed that the intercalated nanocomposite was successfully synthesized for EVA/o-MMT system,while in the EVA/MMT nanocomposite,MMT were poorly dispersed in the order of μm.An unexpected rubbery plateau modulus of EVA/o-MMT nanocomposite above melting point of EVA was explored by DMA.The possible origins of this high-temperature modulus were analyzed.
