Thermal Treatments on a UDMA-TEGDMA Nanocomposite Doped With Gold Nanorods Investigated by In-situ Raman-Spectroscopy

The impact of heating and cooling cycles on a copolymer mixture of urethane dimethacrylate (UDMA) and triethylene glycol dimethacrylate (TEGDMA), with and without gold nanorod doping was studied by using in-situ Raman spectroscopy. The copolymer was made in a 3:1 ratio and 0.1236 m/m% concentration of 25 nm × 85 nm gold nanorods was added. Heating and cooling between 30 °C and 140 °C was applied and two distinct vibration bands at 1447 cm^-1 (C–H bond) and 1638 cm^-1 (methacrylate C = C stretching) were monitored using 532, 633 and 785 nm excitations. The degree of conversion (DC) of the polymer was calculated based on the peak intensities. The influence of the gold nanorods, single and multiple thermal cycles, excitation wavelength, and reference peak selection on the calculated DC were analyzed in detail.