A deep investigation into the thermal degradation of urethane dimethacrylate polymer

Abstract

This work investigates in depth the thermal degradation process of a polymer of urethane dimethacrylate (UDMA). UDMA monomer has been widely used in dental restorations and biomaterials. The use of density functional theory (DFT) calculations provided the bases for understanding the structure and reactivity of the UDMA monomer. Simultaneous thermogravimetry–differential thermal analysis, Photovisual Differential Scanning Calorimetry, and mid-infrared spectroscopy (MIR) were used to examine the depolymerization and degradation process. Non-isothermal kinetics made it possible to determine the best fit (n-dimensional nucleation according to Avrami–Erofeev followed by two competitive processes: nth order with autocatalysis by-product and reaction of nth order). Furthermore, the UDMA-P lifetime (5%) was calculated to show a degradation time of 3 years at 100.0 °C. Notwithstanding, techniques such as MIR and nuclear magnetic resonance 13C, 1H linked to DFT calculations helped to elucidate the cleavage positions and possible degradation by-products of UDMA degradation.