Author(s): Alarcon, Rafael Turra [UNESP] ; Gaglieri, Caroline [UNESP] ; dos Santos, Giovanny Carvalho [UNESP] ; Roldao, Juan Carlos [UNESP] ; Magdalena, Aroldo Geraldo [UNESP] ; da Silva-Filho, Luiz Carlos [UNESP] ; Bannach, Gilbert [UNESP]
Date: 2021
Persistent ID: http://hdl.handle.net/11449/208554
Origin: Oasisbr
Subject(s): Depolymerization; DFT; Polymer lifetime; Spectroscopic analyses; Thermal studies
Made available in DSpace on 2021-06-25T11:14:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01
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.
School of Sciences Chemistry Department UNESP - São Paulo State University
School of Sciences Chemistry Department UNESP - São Paulo State University
