Soybean Protein Modification In Adhesive Production Process

Soybean protein is modified to have high viscosity,substitute chemical adhesive,serve as a kind of green adhesive application.In this study,soybean protein was modified by acid and alkali method,p H and temperature method,urea method,urea-phosphate method,pepsinum method,maleic anhydride method and additive application.In acid and alkali treatment,the adhesive had the highest density of 1.00 g/ml at p H 4 and the lowest viscosity 0.05 Pa.s.At p H 6 and p H 7 the non-volatile compounds range to 6.16%.Under different p H and temperature,the heating temperature on modification of soybean protein at p H 2 and 80 oc is the adhesive that have the highest density of 1.03 g/ml and non volatile compounds is 10.61%,at p H 4 and heating temperature of 80 oc,the adhesive has the highest viscosity 3.47 Pa.s.The results of urea modification showed that the increase of p H and urea concentration could lead to a significant increase in the non volatile compounds.At p H 7,the concentration of urea at 4 mol/L had the maximum viscosity of 3.15 Pa.s.The adhesive produced with urea phosphate modification had a density of 1.08 g/ml,the viscosity 13.88 Pa.s and the higher non-volatile compounds were 27.65 %.The adhesive produced by pepsinum modification with 7.5% soybean protein,20 mg/L of pepsinum content,at 25? and 35? of heating temperature,at 80 min had the highest density range to 0.98 g/ml.The maleic-anhydride based adhesive;composed by 0.20 g of maleic-anhydride;0.20 g of sodium bicarbonate;0.20 g of Tween 20;0.20 g of peroxydisulfate and 0.20 g of white latex adhesive had the highest non volatile compounds range to 7.17%.In terms of additive application?Gluten,Calclium chloride anhydrous,Calcium oxide?,as increase the dosage of the additive increased the mesure of density,of viscosity and non volatile compounds;especially with addition of 20 g/L of Calcium chloride anhydrous the density ranged to 1.06 g/m L,the viscosity of 18.42 Pa.s and the non volatile compounds of 19.28%.The results of this study showed that the soybean protein adhesive produced by 20 g/L of Calcium chloride anhydrous?CaCl₂?had the best properties and provided a chemical modification method for soybean protein adhesive industry.