Preparation of polystyrene-poly (vinyl alcohol) double-shell

Abstract

This paper presents preparation of polystyrene-poly(vinyl alcohol) (PS-PVA) double-shell with micro-encapsulation method. In order to improve the gas-barrier property of the PVA shell, a mixture of 2wt% PVA solution and borax are used as matrix for PVA coating. The pH value of the matrix are kept less than 8 to prevent the PVA coating from formation of patch which arise from local gelation and ruin the uniformity of the PVA shell. The resultant PVA coating ranges from 2 μm to 15 μm with uniformity better than 95%.