Biopolymer-based high-barrier multifunctional paper coating formulations

Overview

This solution offers a sustainable paper coating technology based on two naturally derived biopolymers—pullulan, a microbial polysaccharide, and alginate, a marine polysaccharide. Together, these materials form a compostable coating that delivers high oxygen, moisture, and oil barrier performance for paper-based food packaging. The technology directly addresses growing demand for biodegradable alternatives to conventional plastic and fluorochemical coatings used in food packaging, while maintaining the recyclability and compostability of cellulose-based substrates.

Technical specifications

Key features:

• Pullulan component provides strong oxygen barrier properties, high flexibility, transparency, and excellent oil resistance with an oil absorption value as low as 0.9 g/m²
• Alginate component is cross-linked with calcium ions to create a highly water-resistant layer with low moisture permeability
• Films exhibit greater than 85% light transmission in the visible region, preserving the natural appearance of coated paper
• Water vapor permeability values of approximately 1.0 × 10⁻⁹ to 1.2 × 10⁻⁹ g·m·m⁻²·s⁻¹·Pa⁻¹ for both polymers
• Both biopolymers form strong free-standing films and maintain stable compatibility with cellulose substrates
• 100% naturally compostable, supporting circular packaging objectives
• Blending ratios and cross-linking parameters can be engineered and optimized for specific application requirements

Technology readiness level

Laboratory validation has confirmed the barrier, optical, mechanical, and compostability performance of individual pullulan and alginate films. Current and planned next steps include optimizing the blending ratio between the two biopolymers, refining calcium cross-linking conditions and application methods, conducting paper coating trials to identify ideal coat weights, and evaluating the finalized coated paper in practical food packaging scenarios. The technology is positioned for formulation optimization and pilot-scale validation prior to commercial deployment.