Cellusoy biodegradable biopolymer for footwear cushioning and sustainable applications

Overview

CelluSoy is a self-curing, fully biodegradable biopolymer developed from soy protein, a recycled cellulose source such as paper waste, and crosslinking agents composed entirely of generally regarded as safe (GRAS) components. The material offers an environmentally friendly, non-toxic alternative to conventional plastics and is particularly suited to footwear cushioning applications. Its formulation supports both 3D printing and traditional moulding, with curing achievable at room temperature for semi-hard products or through heat application for rigid products. Pigmentation using water-based pigments allows for a wide range of colours, supporting design flexibility and unique visual aesthetics.

Technical specifications

• Composition: Soy protein combined with a recycled cellulose source and GRAS crosslinking agents
• Processing: Compatible with 3D printing and traditional moulding techniques
• Curing options: Room temperature curing produces a semi-hard material; heat-catalyzed curing at 175–200°C produces a fully rigid product in approximately 10 minutes
• Tuneable mechanical properties: Formulation additives enable adjustable strength and resistance, including gradable mechanical properties within a single object
• Tested performance: Compressive strength validated per ASTM D695; tensile strength validated per ASTM D638, with results favourable for athletic footwear cushioning
• Colouration: Achieved through simple water-based pigments for permanent colour change
• Biodegradation: Early soil burial testing shows 51% weight loss in 14 days at 30°C and 70% relative humidity

Technology readiness level

CelluSoy is currently at a mid-stage development level. Core mechanical properties have been characterized using established ASTM protocols, and proof-of-concept samples have been produced through both 3D printing and moulding. Heat-catalyzed curing has been demonstrated but not yet fully characterized. Biodegradation testing is underway with promising early results. Future validation will focus on thermal conductivity and insulation properties, production speed evaluation through injection or compression moulding, durability and stability testing against traditional cushioning materials, and the development of natural hydrophobic lipid coatings to enhance water and sweat resistance without compromising biodegradability.