PAPER making! g! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 11, Number 2, 2025
COATING “Synthesis Characterization and Application of Waterborne Epoxy Resin—A Pulp and Papermaking Perspective”, Jitender Dhiman, Kumar Anupam & Shubham Sharma, Chapter in Recent Advances on Waterborne Epoxy Coatings , Springer Nature. Waterborne Epoxy Resin (WBER) are the polymers which possess hydrophilic nature and are eco-friendly in nature. On curing, these polymers form a robust 3D network structure having high strength, strong adhesion along with great thermal stability. WBER can be prepared using three different techniques: mechanical, emulsification, and chemical modification. WBER provides a wide range of applications in pulp and paper industry. Water borne epoxy resin is an excellent material for coating and hence it provides number of applications in various areas including pulp and paper sector. In paper industry these epoxy resins are utilized for machinery coating for corrosion prevention and also in paper coating which results in enhancement of its physical and barrier properties which helps in providing sustainable packaging material. This chapter is focused on structural systematization of epoxy resins, overview of water borne epoxy resins, preparation, classification, characterization, advantages and applications of water borne epoxy resins. This chapter also depicts the benefits, challenges and future scope of water borne epoxy resins. In this chapter, the work of various researchers on epoxy resin and water borne epoxy resin in pulp and paper industry has also been summarised. “Improved paper barrier properties based on coating by citric acid crosslinking of hemicellulose”, Rui Zhang, Jingjing Chai, Wanting Guo, Peng Lu & Rina Wu, International Journal of Biological Macromolecules , Vol.304(2), April 2025, 140892. As traditional food packaging materials, usage of petroleum-based plastics leads to serious problems due to poor biodegradability and renewability. The feasibility of using hemicellulose (HC) as a coating to prepare paper packaging materials with barrier properties was explored. Hemicellulose collected as by-product in dissolving pulp production was modified by carboxymethylation and hydroxypropylation, confirmed by FT-IR analysis. The prepared hemicellulose was cross-linked with the green crosslinking agent citric acid (CA) and applied to the surface of the paper to evaluate the effect of the coating on the barrier properties of the paper. When the coating amount reached 9.7 g / m 2 , the oil-proof grade of the coated paper increased from 0 to 6, and the water contact angle reached 72.60 ± 7.91°. The water vapor transmission rate was reduced from 1082.7 g/ (m 2 ·24 h) to 312.5 g/ (m 2 ·24 h), and the coated paper had good organic solvent resistance. Also, the mechanical properties of the paper and hot oil-resistance were improved. The coating used had high stability and the coated paper could be easily recycled. This work provides an environmentally friendly and facile way for improving the barrier performance of paper, which could be used in food packaging. “Waterborne blocked isocyanate crosslinked cationic starch/polyvinyl alcohol coating for improving barrier and mechanical properties of paper-based materials”, Yuyang Wu, Haizhen Shi, Junchao Wen, Xinwang Cao, Hongkai Li & Shengyu Li, International Journal of Biological Macromolecules , Vol.310(4), May 2025, 143436. Green and renewable paper-based packaging materials are gaining more and more popularity, however, issues such as poor barrier and mechanical properties need to be solved. Herein, cationic starch (CS) and polyvinyl alcohol (PVA) were used as paper coatings, with waterborne blocked isocyanate (WBI) serving as a cross-linking agent to eliminate the hydroxyl groups. CS/PVA and CS/PVA/WBI were coated on kraft paper using a bar coating machine at 8 g/m 2 . The composite paper exhibited excellent liquid and gas barrier properties with water and oil absorption values of 8.28 and 9.60 g/m 2 , which were reduced by 71.27% and 57.29%, respectively, compared to the control sample. The WVTR
Technical Abstracts
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