Photopolymerization Kinetics of Block Polyether Based Terminal Urethane Methacrylate with/without Cross‐Linker

Abstract

The present work deals with the photopolymerization of difunctional macromonomer with a polyether chain and urethane methacrylate terminations. Macromonomeric formulations were prepared by mixing macromonomer with two different concentrations of photoinitiator. Formulations were also prepared by the addition of 10 wt% of soft-segmented difunctional cross-linker to the abovementioned macromonomic formulations. All formulations were then subjected to photopolymerization studies and the effects of light intensity on the photopolymerization kinetics were studied at two different isothermal conditions using photo differential scanning calorimetry (Photo DSC) with polychromatic radiation. The isothermal heat flow against time was recorded for all formulations and the kinetic parameters were noted. It was observed that the rate of maximum polymerization as well as peak maximum time showed a general trend. However, the ultimate conversion as well as the conversion at maximum rate did not show any trend due to diffusional restrictions imparted by the increase in viscosity with conversion. The photopolymerization of the formulations and curing kinetics including evaluation of autocatalytic model are discussed. C

Modified epoxy acrylate resin for photocurable temporary protective coatings

“…Because the gelation of the samples at an early stage of the reaction, in which phase separation in monomer-polymer mixtures occurred, hindering the termination reaction [38]. On the other hand, T g of the formulations in the study were found to be around 50-90 • C. Hence, the system vitrified on cure as the analysis isothermal temperatures were lower than the ultimate T g observed on cure, what also reduced the extent of double bond conversion [39,40].…”

Influence of hydrogen bonding interactions on the properties of ultraviolet‐curable coatings

“…Viscosity is an important property of oligomers that controls the diffusion process in photopolymerization reactions . Figure shows the viscosity of NEA resins at 60°C.…”

Influence of a long‐side‐chain‐containing reactive diluent on the structure and mechanical properties of UV‐cured films

“…Viscosity is an important property of oligomers that controls the diffusion process in photopolymerization reactions. 26 Figure 3 shows the viscosity of BFA blends with different HEMA-DDSA contents at room temperature. The viscosity of BFA oligomer was found to be higher than 1 × 10 5 mPa s. According to the experimental data, the addition of HEMA-DDSA and TMPTA could reduce the viscosity of the UV-curing system effectively.…”