Photopolymerization kinetics of 2-phenylethyl (meth)acrylates studied by photo DSC

Abstract

The present work deals with the photopolymerization of 2-phenylethyl (meth)acrylates and estimation of their kinetic parameters. Formulations were made by independently homogenizing the monomers with photoinitiators of two different classes. Two different compositions of photoinitiators were used to study the effect of concentration of photoinitiator on cure kinetics. These compositions obtained were tested for photo curing performance using differential photocalorimetry (DPC) or photo DSC under polychromatic radiation. The heat flow against time was recorded for all formulations under isothermal conditions and the rates of polymerization as well as the percentage conversions were estimated. It was observed that due to a longer timescale for reaction diffusion, the methacrylate formulations showed a higher conversion than acrylate formulations. Other parameters such as induction time, maximum rate and conversion attained as well as the time to attain peak maximum were noted. The photopolymerization and kinetic estimations of the formulations including evaluation of kinetic models are discussed.

High biorenewable content acrylate photocurable resins for DLP 3D printing

“…However, the resins with slower reacting methacrylate RDs, AESO/IBOMA and AESO/THFMA, showed the higher G ′ values at the end of the process and thus more rigid polymers were formed in these cases. This observation correlates with previously determined the higher conversion of methacrylate groups in comparison to acrylate groups resulting in polymers with better mechanical properties 48 . Moreover, it was observed that the rate of cross‐linking was associated with the material shrinkage during the photopolymerization 49,50 .…”

“…This observation correlates with previously determined the higher conversion of methacrylate groups in comparison to acrylate groups resulting in polymers with better mechanical properties. 48 Moreover, it was observed that the rate of cross-linking was associated with the material shrinkage during the photopolymerization. 49,50 The shrinkage is caused by the transformation of intermolecular distances $3-5 Å linked via weak Van der Waals force into the typical C C strong covalent bond distance $1.54 Å.…”

The influence of monomer chemistry on radical formation and secondary reactions during electron‐beam polymerization

“…The low final conversion of the methacrylates compared to the acrylates is not necessarily surprising. Other researchers have observed the slow reaction rates of methacrylates compared to acrylates during photopolymerization reactions . The slow R p values of methacrylates have been attributed to the stability of the tertiary propagating methacrylate radical (in comparison to the secondary propagating acrylate radical), as well as the increased steric hindrance caused by the additional C─H bonds .…”

Biodegradable, Solvent‐Free Photocrosslinkable PLLA Resin Formulations for Additive Manufacturing

“…This parameter can be obtained using the Jacob's equation based on the Beer‐Lambert law shown in Equation (1) [ 58,59 ] $$\begin{equation}{C_{\rm{d}}}\; = \;{D_{\rm{p}}}\;{\rm{ln}}\frac{{{E_0}}}{{{E_{\rm{c}}}}}\end{equation}$$…”