The Study of the Influence of Chemical Nature of Functional Groups in Oligomeric and Low--Molecular Modifiers on the Rheological Properties of the Epoxy Oligomer

Abstract

The influence of chemical nature of modifier functional groups on the level of intermolecular interactions in the system "epoxy oligomer ‒ modifier", as well as the structure formation and dynamic viscosity of epoxy oligomer has been studied in detail. Modifying additives in low concentrations contribute to an increase in the degree of structure formation of the epoxy system by increasing the intermolecular interaction between the associates of the epoxydiane oligomer. It was established that the strength of the formed coagulation structures depends both on the compatibility parameter of the modifiers and ED-20, and on their intermolecular interaction energy.

Photopolymerization of Poly(Hydroxyethyl Acrylate) (PHEA): Experimental Parameters-Viscoelastic Properties Relationship

“…However, the initial experimental factors such as MB/TEOA concentration and pH may be affecting significantly the resultant complex viscosity of the PHEA. This result can be caused by the number of radicals formed in the initiation step of polymerization which define the chains length of the synthesized product, as reported by Zhang et al 16 and Chaudhuri et al 17 In our case, we can suggest that the radicals initiators formed in the case of PHEA M0.01T3P7 , are more important than those of PHEA M0.01T5P7 because some TEOA molecules were interacted with MB singlet state and deactivated the formation of radical initiators. Therefore, the chains formed in the case of PHEA M0.01T5P7 are longer and the entanglement greater, leading to an increase in the polymer viscosity.…”

“…14 These encouraging results showing the correlation between the molecular structure and mechanicalrheological properties have recently garnered the curiosity of several researchers with the aim of predicting the per-formance of properties by modifying experimental conditions to better target the desired application. 15,16 To keep up with the evolution of VLIP technology, a short overview of the literature shows that the photoinitiator chemical composition strongly influences the polymerization kinetics, 17 whilst its effect on viscoelastic properties of resulting polymers is not well investigated. On the other hand, and to our knowledge, the effect of pH and the concentration of each photoinitiator constituent on kinetics and viscoelastic properties remains to be discussed.…”