Pressure-coupled chemical foaming enables dual-scale matrix–cellular synergy in polyurethane elastomers

The rational design of microcellular polyurethane elastomers (MPUEs) with dual-scale matrix–cellular synergy is realized through a novel high-pressure coupled chemical foaming (HPCCF) strategy. By employing pressurized impingement mixing, HPCCF synchronizes urea-network formation and bubble nucleation, thereby overcoming the intrinsic kinetic conflict in conventional foaming processes. Precise regulation of foaming pressure enables the construction of refined cellular architectures—achieving a 63% reduction in average cell size, a narrower size distribution, and a 12.5-fold increase in cell density. Multi-scale characterization techniques, including FOAMAT, SAXS, AFM, SEM, DIC, and in situ CT, demonstrate that HPCCF simultaneously enhances microphase separation and mechanical synergy. Quantitative analysis of deformation partitioning reveals that the cellular structure accounts for 86% (M-78) and 91% (M-210) of total deformation at 10% strain, decreasing to 80% and 82% at 50% strain, respectively. Such cooperative matrix–cellular load bearing promotes homogeneous strain distribution and enables over 90% elastic energy recovery across 100 compression cycles. This work pioneers a quantitative paradigm for dual-scale deformation management, establishing a generalizable framework for designing advanced vibration isolation materials with ultra-low energy dissipation and exceptional cyclic durability.