Melt elasticity behaviour and extrudate characteristics of LLDPE/EVA blends: effect of blend ratio, compatibilisation and dynamic cross-linking

摘要

A study on the melt elasticity behaviour and extrudate characteristics of linear low density polyethylene (LLDPE)/ethylene vinyl acetate (EVA) blends was done. Extrusion studies were carried out in a capillary rheometer. Examinations of the surface characteristics of extrudates were made by taking photographs. With a view to characterize melt elasticity of these blends, parameters such as die swell, principal normal stress difference, recoverable shear strain, and shear modulus were calculated. Melt elasticity of the blends increases with EVA concentration and shear rate. The morphology of the blends was modified by physical compatibilisation process and dynamic vulcanisation. Compatibilisation reduces extrudate deformation, whereas dynamic cross-linking increases extrudate deformation and fracture.