Influence of Dimethacrylate Monomer on the Polymerization Efficacy of Resin-Based Dental Cements—FTIR Analysis

The degree of polymerization for dimethacrylate resin-based materials (BisGMA, TEGDMA, UDMA, HEMA) ranges from 55 to 75%. Literature data indicate that polymerization efficacy depends, among other factors, on the type of methacrylate resin comprising the material. The aim of this study was to evaluate the polymerization efficacy of four dental cement materials characterized by different polymerization mechanisms using FTIR analysis. In the present study, the FTIR method was adopted to analyze the degree of polymerization efficacy of four resin-based dental cement materials, two of which were self-cured and two were dual-cured cements. The IR spectral analysis was performed 24 h after the polymerization of the cementitious material. RelyX ARC cement exhibits the lowest polymerization efficacy (61.3%), while that of Variolink II (85.8%) and Maxcem Elite is the highest (90.1%). Although the efficacy of self-cured cements appears to be superior, the difference is not statistically significant (p = 0.280). Polymerization efficacy largely depends on the chemical structure of the material in terms of the presence of a particular methacrylate resin and less on the polymerization mechanism itself, i.e., whether it is a self-cured or dually cured dental cement. Thus, in clinical practice, cementitious materials with a higher proportion of TEGDMA compared with BisGMA are recommended.

Reactive separation of β-bromoethylbenzene from α-β-bromoethylbenzene mixtures: A Zn2+-mediated radical polymerization mechanism

A Zn2+-induced reactive separation method for the purification of β-bromoethylbenzene from α-β-bromoethylbenzene mixtures is discovered, where the selective decomposition of α-bromoethylbenzene follows a radical mechanism. Zn2+ facilitates the homolysis of...

On the mechanism of acrylamide emulsion polymerization with the participation of its dimers

The role of both dimeric and monomeric forms of acrylamide monomer in the process of polymerization in emulsions initiated by different type of initiators was discussed and the reasons for the reaction order with respect to monomer greater than unity were elucidated for acrylamide free radical polymerization in emulsions. The emulsion polymerization mechanism of acrylamide is discussed separately for the processes initiated by water-soluble initiator and oil-soluble initiator. The main difference in two cases is the distribution of acrylamide and initiator in aqueous and toluene phases. In the case of using water-soluble initiator, the initiator and acrylamide are in the same phase, whereas the molecules of the initiator and acrylamide are distributed between different phases in the case of using oil-soluble initiator. As a result, the participation of the dimers in the process of acrylamide emulsion polymerization is more efficient for the system where water-soluble initiator is used. For that system, it is suggested that both dimers and monomers of acrylamide participate in the propagation reaction at relatively low concentrations of acrylamide, which explains the value of the reaction order with respect to monomer greater than unity.

Rationalizing the Role of Monosodium Glutamate in the Protein Aggregation Through Biophysical Approaches: Potential Impact on Neurodegeneration

GRAPHICAL ABSTRACT 1Kinetic measurements indicating that monosodium glutamate causes significant enhancement of aggregation of protein through nucleation-dependent polymerization mechanism. Even low concentration of MSG is involved in the unfolding of secondary structure of protein with the disappearance of original peaks (208 and 222 nm) and formation of unique peak (226 nm) in the far-UV CD.

Experimental validation of eosin-mediated photo-redox polymerization mechanism and implications for signal amplification applications

When eosin-mediated, photo-redox polymerization is used to amplify signals in biosensing, oxygen has dual, opposing roles.