Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Microporous TPU foam modified with vinyl triethoxysilane-treated cellulose exhibits a unique “flower-like” cellular architecture. This hierarchical network, resembling architectural frameworks, enhances interfacial compatibility and structural stability. The resulting material achieves exceptional compressive strength (58.25 kPa) and rebound resilience (90.25%) while maintaining low shrinkage, offering a promising strategy for dimensionally stable, high-performance polymer foams.

ABSTRACT
Thermoplastic polymer foam faces shrinkage challenges. By adding modified microcrystalline cellulose into the polymer, thermoplastic polyurethane foam with low shrinkage and high mechanical properties was studied. The results showed that the modified microcrystalline cellulose improved the dispersion and compatibility of microcrystalline cellulose in the polymer matrix, and the composite foam formed a reinforced network structure bridged by microcrystalline cellulose. By connecting adjacent holes, it constructs a unique “flower-like” hierarchical branching interface structure. This novel network honeycomb structure based on microcrystalline cellulose is similar to the primary and secondary framework features in architecture, which significantly improves the mechanical properties of foam materials and improves the shrinkage and resilience of foam. The typical microporous foam with an average pore diameter of 8.65 μm was successfully prepared using 15% vinyl triethoxysilane-modified MCC, exhibiting a cell density of 1.56 × 1010 cells/cm3. While maintaining a shrinkage rate below 28.17%, the maximum compressive stress increased by 66.96%, with compressive strength and rebound elasticity values of 58.25 kPa and 90.25%, respectively, after 10 loading–unloading compression cycles. This study laid a theoretical foundation for the rational formulation design of TPU-based composite foam materials, demonstrating their dimensional stability against shrinkage, excellent compressive elasticity, and mechanical properties.