Study on Protein Based Adhesives Blending-Modified by Isocyanate

Abstract

The price of cotton by-product cottonseed meal has been relatively stable and significantly lower than that of soybean meal, which has greater advantages for industrial raw materials. Cottonseed meal after cottonseed oil extraction accounts for 30% of the total content of plant meal, and the protein contained in cottonseed meal is not lower than soybean protein in terms of quality and quantity. At present, cottonseed meal, as a by-product of cottonseed oil extraction, is mainly used in animal feed, and cottonseed protein is not fully utilized. In this study, cottonseed meal was used as raw material. By studying the effects of modifier addition and reaction conditions on the bonding properties of cottonseed adhesive, the best process parameters for preparing the best cottonseed adhesive were explored, and the modification mechanism of cottonseed protein adhesive was revealed by analyzing the adhesives prepared under different conditions. The results showed that the solid content increased with the increase of isocyanate addition ratio, and the application period of the adhesive shortened with the increase of isocyanate addition ratio. When the addition amount was 40%, a large number of bubbles were produced in 30 minutes. The water resistance of blended modified cottonseed adhesive was tested. When the proportion of isocyanate was less than 10%, the water resistance bonding strength could not meet the requirements of national standard. Adding more than 10% isocyanate cottonseed protein adhesive to bond plywood can well meet the standard of class II plate, and the maximum bonding strength can reach 1.68mpa. The research results can not only provide a certain theoretical basis and practical guidance for the preparation of new low-cost green adhesive, but also open up a new way for the effective utilization of agricultural and forestry waste cottonseed meal.