MOISTURE/SORPTION CHARACTERISTICS OF STARCH-FILLED POLY (STYRENE-CO-BUTYL ACRYLATE) LATEX BASED COMPOSITES REINFORCED WITH POLYESTER NONWOVEN FABRIC

Abstract Poly (styrene-co-butyl acrylate) latex was prepared with a 70:30 weight ratio of styrene to butyl acrylate. The prepared latex was incorporated with various weight percentages of cornstarch. The cornstarch-filled copolymer latex was used as a matrix to fabricate the polyester nonwoven fabric reinforced composites. The pickup ratio of latex to fabric was maintained at 3.2:1. The moisture sorption characteristics of composites were examined at 27⁰C for water activity (aw) from 0.1 to 0.9. The sorption data was used to fit six different sorption isotherm models proposed in the literature. The model constants were determined by linear fitting of the sorption equations. The ranges of applicability of water activity for the isotherm models reported in the article lies between 0.1 and 0.4 (monomolecular layer) for the Braunauer-Emmet-Teller (BET) model, and between 0.3 and 0.9 (multimolecular and capillary condensation layers) for other models. The value of the coefficient of determination (R2 = 0.97±0.02) confirms the linear fitting of the equations studied.