AB crosslinked polymers based on cationomeric polyurethane and poly(methyl methacrylate): Static and dynamic mechanical studies

Vinyl‐terminated polyurethane (VTPU) was prepared by end‐functionalizing isocyanate‐terminated prepolymers with 2‐bromoethanol and subsequently quartenizing with 4‐vinylpyridine. The vinyl functionality was then effectively utilized for preparing AB crosslinked polymers (ABCPs) with methyl methacrylate (MMA). ABCPs prepared with variable weight ratios on PTMG₁₀₀₀‐based VTPU/MMA (8/2, 6/4, 5/5, 4/6, 2/8) and those prepared at a 5/5 weight ratio with different polyols (PTMG₁₀₀₀, PPG₁₀₀₀, and PCL₁₂₅₀) in VTPU were characterized by Fourier transform infrared spectroscopy (FTIR) and further analyzed for thermal and mechanical properties. FTIR spectral results confirm quartenization of heterocyclic nitrogen, leading to crosslinking. Thermogravimetric analyses show enhanced thermal stability of the crosslinked systems. The stress–strain measurements reveal increasing tensile strength with increasing amounts of MMA. Comparison of dynamic mechanical spectra of ABCPs based on PTMG₁₀₀₀ shows that the 5/5 composition exhibits good damping over a broad temperature range. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 813–821, 2001