Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Surface-modified silica nanoparticles bearing tertiary amine groups are incorporated into MOCA-based cast polyurethane at only 0.3 wt% loading. The strong interfacial covalent and hydrogen bonding significantly improves filler dispersion, boosts tensile strength to 59.1 MPa, and reduces abrasion volume by 34%, offering a highly effective route to wear-resistant elastomers.

ABSTRACT
4,4′-Diaminodiphenylmethane (MOCA)-based cast polyurethane (CPU) elastomers possess excellent mechanical properties but often exhibit insufficient wear resistance under high-load or abrasive conditions. To address this, surface-modified silica nanoparticles (D-SiO2) were prepared using (N, N-dimethyl-3-aminopropyl)trimethoxysilane (DAPS) and incorporated into the CPU matrix via a solvent-assisted casting method. The introduced tertiary amine and organic groups on D-SiO2 facilitated covalent bonding and hydrogen bonding with the CPU, significantly enhancing interfacial compatibility and dispersion uniformity. At an optimal loading of 0.3 wt%, the composite achieved a remarkable tensile strength of 59.1 MPa and an elongation at break of 394.75%, representing a substantial improvement over the neat CPU (44.2 MPa, 376.33%). Furthermore, the wear resistance was notably enhanced, with the abrasion volume reduced by 34% compared to the unfilled system, while the friction coefficient remained stable. This work demonstrates that low-loading, surface-modified silica can effectively reinforce MOCA-based CPUs, offering a viable strategy for developing high-performance MOCA-based CPU elastomers.