Cottonseed Hull Cellulose -Modified Polyether Polyol Polyurethane Foams: Enhanced Thermal Insulation and Degradability

Rigid polyurethane foams (RPUF) are extensively utilized across various industrial and construction sectors due to their exceptional thermal insulation and mechanical properties. However, their primary raw materials, specifically diols and polyether polyols, are predominantly derived from the depleting petrochemical industry. Consequently, these conventional materials present inherent global challenges regarding long-term non-degradability, ecological persistence, and severe environmental pollution. In this comprehensive study, we demonstrate an innovative and sustainable method for preparing eco-friendly polyurethane foams via a highly efficient one-step foaming process. This approach utilizes Cottonseed Hull Cellulose (CHC), an abundant agricultural byproduct, to partially replace conventional petroleum-based polyether polyols. Microstructural analysis reveals that the resulting CHC-modified polyurethane foam exhibits a highly uniform cell distribution and successfully forms a dense, protective aromatic char layer upon combustion, significantly enhancing fire resistance. Specifically, the optimized foam formulation with a 40% CHC substitution rate exhibits an ideal apparent density of 0.049 g/cm^3 and maintains a remarkable residual mass of 41.76% at elevated temperatures of 600 °C. This constitutes a significant structural and thermal enhancement compared to traditional foams formulated without CHC, effectively improving the material's overall thermal insulation properties and thermal stability. Furthermore, the CHC-integrated polyurethane foam demonstrates a maximum degradation rate of 36.01% under controlled conditions, indicating excellent environmental degradability. Ultimately, this work proposes a novel, scalable approach for the sustainable preparation of high-performance polyurethane foams and offers a promising new perspective on the high-value utilization of renewable biomass resources.