Onomer (g) x 1.7 5.8 11.three 1.6 five.1 9.5 mphotoinitiator (g) 3 three.two three 3.2 2.9 three.1 3.2 (cP) 2336 2285 2407 2271 2301 2174Formulations have been applied on metallic Q-panels R36 (Q-lab, Westlake, OH, USA) (or glass panel for the pendulum damping test) with a 100 gap square applicator film PA-5353 (BYK Additives Instruments, Columbia, SC, USA). Film polymerization was performed applying a UV oven ATG 160 305 (Ayotte techno-gaz, Lourdes-de-Joliette, QC, Canada), having a medium stress mercury light UV mac ten (Nordson, Westlake, OH, USA) emitting amongst 200 and 500 nm. The oven was set to receive a UV irradiation of 150 mW/cm2 and 200 mJ/cm2 . 2.3. Physicochemical and Mechanical Characterization 2.3.1. Fourier Transformation Infrared Spectroscopy Measurements (FTIR) Fourier transformation infrared spectroscopy (FT-IR) measurements were employed to figure out the conversion yield on the coatings. The Spectrum 400 spectrophotometer (Perkin Elmer, Woodbridge, ON, Canada) was applied with an attenuated total reflectance accessory (ATR). Measurements have been realized on each and every film (polymerized) and formulation (liquid) between 650 cm-1 and 4000 cm-1 (32 scans by measures, resolution of 4 cm-1). Baseline correction and normalization on carbonyl peak (1710 cm-1) were applied on every single film. Stretching vibration on the carbonyl at 1710 cm-1 (reference peak) as well as the twisting vibration of alkene at 810 cm-1 (Figure two) had been utilised to measure conversion yield (Equation (1)). The equation selected is the 1 presented in Furtak-Wrona’s paper [22]. The stretching vibration with the alkene is visible at 1635 cm-1 , but the amine group, present in the acrylated allophanate oligomer, vibrates nearby. As a result, this peak was not utilized for the calculation. Equation (1) is calculated as follows: = 1- Aacryl A0 ref A0 acryl Aref(1)where Aacryl and A0 acryl will be the absorbance in the acrylate peak with the cured film as well as the uncured formulation, respectively. At the similar time, Aref and A0 would be the absorbances of ref the reference peak inside the cured film as well as the uncured formulation, respectively. two.three.2. Dynamic Mechanical Evaluation Measurements (DMA) DMA measurements were performed following the same process utilized within the initially part of the study [15]. Coatings’ glass transition temperatures were determined utilizing the p-Toluic acid Cancer maximum loss modulus. The maximum loss element (tan, Equation (two)) is also noted to know the finish temperature of the glass transition. Cross-linking densities (CLD) were measured from the minimum of storage modulus (Equation (3), Figure three). To become repeatable, the minimum storage modulus is taken at the temperature Tg 50 C. As performed previously, the samples have been cut with CO2 laser machine (LMC-2000 from Beam DynamicCoatings 2021, 11,six ofat 500 W, Edgar, WI, USA) at two.five cm 0.5 cm. Equations (two) and (three) are calculated as follows: E loss modulus tan = (two) E storage modulus CLD = min E three R T (3)Coatings 2021, 11,exactly where tan may be the loss element, E the loss modulus, E the storage modulus, CLD the crosslinking density (in mol/m3), R the gas continuous (in Pa.L/mol.K), and T will be the temperature six of 20 at Tg 50 C (in K). CLD was measured from E , the storage modulus inside the DTSSP Crosslinker ADC Linker rubbery C (in Pa). plateau at Tg Coatings 2021, 11,Figure 2. FTIR spectrum of your HEMA-PETA-Ebecryl 4738 formulation (n). The red curve is definitely the Figure 2. FTIR spectrum of the HEMA-PETA-Ebecryl 4738 formulation (n two). The red curve is the cured film, as well as the blue curve would be the uncured formulation. cured film, and the blue curve will be the.
