Processibility and Miscibility Studies of Uncompatibilized Linear Low Density Polyethylene/Poly(Vinyl Alcohol) Blends

This work investigates the processibility and miscibility of linear low density polyethylene (LLDPE) and poly(vinyl alcohol) (PVA) blends. The linear low density polyethylene/poly(vinyl alcohol) was blended to give the following blend ratio (wt%): 100/0, 90/10, 80/20, 60/40, 50/50, 40/60. The blends were melt mixed using a Haake Rheometer at 150 degrees C and 50rpm for 10min. Thermal properties and morphology of the blends were investigated by using differential scanning calorimetry and scanning electron microscopy (SEM). The effect of blend ratio on tensile properties of LLDPE/PVA blends was also examined. Both components were immiscible, as been confirmed by double melting temperature, corresponding to linear low density polyethylene and poly(vinyl alcohol). Increasing content of poly(vinyl alcohol) resulted in decreased in the tensile strength and elongation at break but an increased in Young's modulus of linear low density polyethylene/poly(vinyl alcohol) blends up to a certain level beyond which these values gradually decreased. Evidence of immiscibility of LLDPE/PVA blends was also confirmed by the presence of agglomerates as revealed by SEM. It was purposed that the difference in degree of polarity contribute to the low miscibility between the two components.