Properties of blends from pregelatinized starch with poly (vinyl alcohol) for hygienic-purposed disposable laundry bags

Abstract

This research was focused on the properties of poly (vinyl alcohol) (PVOH) blended with pregelatinized starch (PSt) as a suitable material to make laundry bags for infected clothes application. PVOH and PSt (0, 10, 20, 30, and 40 wt.%) with glycerol 20 phr were melt-blended by twin-screw extruders. The samples were processed into the film by single layer-blown film extrusion. From the results, it was found that PVOH, glycerol, and pregelatinized starch had intermolecular interactions with each other, forming hydrogen bonding interactions between PVOH/pregelatinized starch and glycerol. The glass transition temperature (Tg) of a blend was shifted to a higher temperature by increasing the pregelatinized starch content leading to a reduction in the percent crystallinity. The presence of pregelatinized starch slightly increased the melt flow rate (MFI)/melt volume rate (MVR), apparent viscosity, and viscosity average molecular weight (Mv) of the blends due to the chain entanglement but it decreased the water solubility time and the moisture content. A co-continuous phase with small coalescence was found when 30% pregelatinized starch was added, increasing the elongation at break to 171%. On the other hand, the pregelatinized starch content was 40%, the elongation at break reduced to 154%.