Title
Utilization of bio-based polymers and dimethylol dihydroxyethylene urea in coating kraft packaging papers
Authors
MERYEM ONDARAL and EVREN ERSOY KALYONCU

Received June 24, 2024
Published Volume 59 Issue 1-2 January-February
Keywords guar gum, soya protein isolate, whey protein isolate, Kraft paper, food packaging

Abstract
The use of polymers in food packaging that do not harm human health and are biodegradable provides a reliable and environmentally friendly packaging option. In this study, the use of biodegradable polymers, such as guar gum (GG), whey protein isolate (WPI), and soy protein isolate (SPI), with the addition of dimethyloldihydroxyethyleneurea (DMDHEU) as a surface coating, on unbleached kraft food packaging papers was investigated. For this purpose, 3% SPI, 0.5% GG, 6.0% WPI, and four different amounts of DMDHEU (0%, 0.5%, 1.0%, and 1.5%) were used. Mechanical properties, including tensile strength, tear resistance, and burst strengths were determined; physical properties including Cobb and air permeability tests were conducted, and scanning electron microscope images of paper samples were analyzed for characterization. Improvements were obtained in the tensile strength of papers coated with all three of the biopolymers used without DMDHEU. The highest breaking resistance was obtained with GG. While the tear index value improved with GG and SPI, it decreased with WPI. Moderate decreases were observed in burst index values, with the lowest values obtained with WPI. It was determined that the water repellency of GG, SPI, and WPI-coated papers decreased, while air permeability resistance increased. SPI, GG, and WPI biopolymers are expected to serve as coating materials in packaging paper production.