Effect of raw and cationic starch Iranian oak (Quercus Persica) fruit (Acorn) as a novel biopolymer on properties improvement of dry network and cellulosic fiber suspension

Oak fruit is naturally produced as a huge amount of biopolymer in Iranian forests, annually. In this study, the fruit starch was isolated by the alkaline method (known as A3S) and modified with 3-chloro-2-hydoxypropyl trimethylammonium chloride (QUAB188) and then, applied as a cationic additive in cellulosic fiber suspension.. The Fourier transform infrared spectroscopy (FTIR) and Kjeldahl analyses of both cationic and raw biopolymer approved the nitrogen content (0.359%) with a degree of substitution (DS) of quaternary ammonium (0.045) on anhydroglucose units of cationic starch. The results showed that the raw starch has significantly superior effects on properties of both cellulosic fiber suspension as well as fiber network compared to the cationic biopolymer. Indeed, several properties of cellulosic fiber suspension such as drainage time, retention and water retention value improved while for the fiber network an enhancement in apparent density and strength indices of tensile, burst, and tear was observed. For example, the raw biopolymer revealed up to 43% higher tensile index of the prepared network and > 2% retention of the suspension compared to the cationic starch, the more uniform paper sheet formation obtained from Oak raw starch compared to the cationic starch can be attributed the high DS of cationic starch, higher module of elasticity, and decreasing molecular weight of polymer during cationization process. In addition, the other properties were considerably improved by the employment of both local biopolymers, except drainage time; which can be due to the improvement of flocculation, retention, ingredients bonding, and density.