The Miscibility of Polymer Blends Improvement of the Miscibility of LDPE/PVA Blend by Different Additives

A polymer blend is a mixture of two or more different species of polymer. From a thermodynamic point of view, most polymer pairs are immiscible. The inherent immiscibility and in number of cases, the large interfacial tension make it difficult to obtain a fine dispersion of the blend components during melt mixing, and under quiescent conditions, it drives phase coarsening phenomena such as coalescence. Furthermore, most immiscible polymer blends suffer from a poor interfacial adhesion which causes inferior mechanical properties in the solid state. To overcome these short comings and to obtain commercially useful blends, compatibilization is necessary. In this work three types of compatibilizers (maleic acid, silane and glycerin) was used to improve the miscibility of low density polyethylene and poly (vinyl alcohol). The blends was prepared via twin screw extruder with different weight proportion with the addition of 5% wt. of each compatibilizer.