Małgorzata Noworyta, Monika Topa-Skwarczyńska, Paweł Jamróz, Dawid Oksiuta, Małgorzata Tyszka-Czochara, Klaudia Trembecka-Wójciga, and Joanna Ortyl
Published: 23 June 2023 | Special Issue Molecular Research on Chemical, Physical and Optical Properties of Materials
Photopolymerization is a growing field with an extensive range of applications and is environmentally friendly owing to its energy-efficient nature. Such light-assisted curing methods were initially used to cure the coatings. However, it has become common to use photopolymerization to produce 3D objects, such as bridges or dental crowns, as well as to cure dental fillings. In this study, polymer nanocomposites containing inorganic nanofillers (such as zinc nano-oxide and zinc nano-oxide doped with two wt.% aluminum, titanium nano-oxide, kaolin nanoclay, zirconium nano-oxide, aluminum nano-oxide, and silicon nano-oxide) were fabricated and studied using Real Time FT-IR to investigate the effects of these nanoadditives on the final conversion rates of the obtained nanocomposites. The effects of the fillers on the viscosity of the produced nanocomposites were also investigated, and 3D prints of the selected nanocomposites were presented.
Keywords: nanomaterials; nanotechnology; photopolymerization; polymer nanocomposites; radical polymerization; cationic polymerization
Figure 4. Absorption spectrum of (a) Sylanto 7 MP photoinitiator dedicated to cationic photopolymerization, and (b) TPO-L photoinitiator dedicated to radical photopolymerization.
First, the absorbance measurements of the initiators in acetonitrile were performed. It was demonstrated that both TPO-L and Sylanto 7 MP absorbed in the range up to just over 400 nm (Figure 4). For the TPO-L photoinitiator, the wavelength for the maximum molar extinction coefficient was shifted towards longer wavelengths, compared to the Sylanto 7 MP photoinitiator. The maximum molar extinction coefficient at the longest wavelength band (349 nm) for the photoinitiator Sylanto 7 MP was 17,347 dm3·mol−1·cm−1 (Table 1). The maximum molar extinction coefficient in the longest wavelength band at 371 nm for the TPO-L initiator was 239 dm3·mol−1·cm−1.