Polymer-graphene composites by photocuring of a system containing benzophenone macromer

Abstract

Formulations incorporating benzophenone-oligodimethacrylate (BP-DMA) and graphene structures, i.e., graphene oxide (GO) and reduced graphene oxide (RGO), were exposed to UV-Vis irradiation or a femtosecond laser beam to achieve hybrid composites. All structures were characterized through various methods, including 1 H-NMR and FTIR spectroscopies, optical microscopy, TEM, ESEM/EDAX analysis and DSC/XRD techniques. The photopolymerization of BP-DMA in the monomer compositions with and without GO or RGO was investigated by photo-DSC and FTIR methods to determine the kinetic parameters of the polymerization. The photopolymerization experiments revealed a good photoreactivity of the monomers (degree of conversion: 65-77 %) after 1 min exposure to UV-Vis irradiation and the addition of graphene (up to 0.5 %), whereas the polymerization rate varied between 0.14 and 0.1 s-1. Moreover, two-photon photopolymerization of the formulations in the presence/absence of GO or RGO nanosheets (0.1 wt. %) generated 2D microstructures by the direct laser writing procedure. Furthermore, the morphology and the properties of composites materials were analyzed.

3D Printing of High Viscosity UV‐Curable Resin for Highly Stretchable and Resilient Elastomer

“…The intensity of the typical ester carbonyl group absorption peak (C═O) at ≈1720 cm −1 in the FT‐IR spectra could be employed as the internal standard to completely minimize the impact of scattering within the film. [ 42 ] The double bond conversion could be determined using Equation (): [ 43 ] $$$$\begin{equation}X\ = \ \frac{{{{\left( {\frac{{{A}_{810}}}{{{A}_{1720}}}} \right)}}_0\ - \ {{\left( {\frac{{{A}_{810}}}{{{A}_{1720}}}} \right)}}_t}}{{{{\left( {\frac{{{A}_{810}}}{{{A}_{1720}}}} \right)}}_0}}\ \times \ \ 100\% \end{equation}$$$$where X denotes the conversion rate of C═C groups. A 0 and A t denote the relative absorptions of ═C─H pre‐ and post‐UV irradiation, respectively.…”

“…The intensity of the typical ester carbonyl group absorption peak (C═O) at ≈1720 cm −1 in the FT-IR spectra could be employed as the internal standard to completely minimize the impact of scattering within the film. [42] The double bond conversion could be determined using Equation ( 1): [43] X =…”

3D printed piezoelectric energy harvesters

“…It is widely used in acrylic polymerization as the photoinitiator. [139,[165][166][167] Then, the photoinitiator TPO (BASF) powder was grinded with a mortar and pestle and added to the mixture. The TPO was dissolved and homogenized by 100 °C water bath heating and shaking with a small mechanical shaker (Vortex Maximix II, Thermo Scientific).…”