Starch-based Surface-sizing Agents in Paper Industry: An Overview

Natural starch is an abundant and inexpensive polysaccharide biopolymer that is widely used as a surface-sizing agent in the paper industry. The surface sizing of paper improves its water and abrasion resistance, as well as its physical strength and printing adaptability. However, natural starch presents some disadvantages, such as high viscosity, poor fluidity, poor film-forming properties, and easy coagulation. Therefore, starch is usually modified and blended with various components to achieve better sizing performance. This article reviews approaches for the surface sizing of paper and modification of starch using enzymes or chemical methods, such as oxidation, cationization, and graft copolymerization. This article also discusses the application of starch-based multiphase systems (obtained by blending starch with various components) as surface-sizing agents.