Study of the Effect of Two Bpo/Amine Initiation Systems on the Free-Radical Polymerization of Mma Used in Dental Resins and Bone Cements

Abstract

The kinetics of the free radical bulk polymerization of methyl methacrylate (MMA) was studied by DSC, using the benzoyl peroxide (BPO)=amine initiation system. N,N dimethyl-4-aminophenethyl alcohol (DMPOH), which is a newly synthesized and used amine in the preparation of acrylic dental resins and bone cements was examined, and the results compared to the most commonly used in these applications amine, the N,N dimethyl-p-toluidine (DMT). For both amines, the effect of the molar ratio of BPO=amine and of the reaction temperature, on the polymerization kinetics was investigated. The prepared polymers were characterized by determination of the average molecular weights ( M n and M w ) and molecular weights distribution ( M w = M n ) using Gel Permeation Chromatography. DMPOH was found to lead in slightly higher polymerization rates, lower gel times and lower molecular weights than DMT. The values of these parameters for both amines were influenced by the molar ratio of BPO to amine, when the product of the concentrations of these was kept constant. The highest polymerization rate occurred in the lowest gel time, resulting in polymers with the lowest molecular weight, and was observed when a molar ratio of about 1.5 BPO=amine was used. However, the final monomer conversion was found to be independent of the molar ratio and amine used. The activation energy of polymerization was found to be 51.8 kJ=mol K for BPO=DMPOH and 47.1 kJ=mol K for BPO=DMT.

Sorption of binary liquid mixtures in methacrylate‐based biomaterials; Simultaneous determination of the diffusion coefficients and the uptake fraction at equilibrium of the components of ethanol‐water mixtures by a new iterative method

“…Finally, the proposed iterative method was successfully applied to the experimental data concerning the sorption kinetics of EtOH-H 2 , and f % 5 7.52. Despite the fact that the proposed iterative method requires laborious calculations, it can be easily applied thanks to the opportunities offered today by high-speed personal computers.…”

“…[1][2][3][4][5][6][7][8][9][10] Monomethacrylates, such as methyl methacrylate (MMA), and dimethacrylates mainly the bisphenol-Adiglycidyl dimethacrylate (Bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA) are widely used in dentistry and orthopedic surgery, because of their established biocompatibility. 11,12 Poly(methyl methacrylate) is used for the construction of denture bases, artificial teeth, and as bone cements; copolymers of dimethacrylates are used in pit and fissure sealants, crown, and bridge prostheses, dentine bonding agents, tooth restorative composites, and also as bone cements.…”

Cure mechanisms in materials for use in esthetic dentistry

“…To provoke the decomposition of BPO at an ambient temperature, cold‐cure (also called chemical cure, self‐cure, or autopolymerizing) acrylic resins need another chemical, usually an aromatic tertiary amine (commonly N , N ‐dimethyl‐ p ‐toluidine [DMPT] or N , N ‐dihydroxyethyl‐ p ‐toluidine [DHPT]) (Figure 2). 26 The role of the tertiary amines is to carry out the redox (reduction–oxidation) initiation, together with BPO in a short period of time at ambient/oral temperature 22,26 . Those amines, which are contained in the liquid, are called the accelerator, activator, promoter, or more precisely, the co‐initiator 7,17,27 .…”

Copolymerization kinetics of dental dimethacrylate resins initiated by a benzoyl peroxide/amine redox system

“…11 In a previous work, we examined the homopolymerization of methyl methacrylate initiated by the BPO/N,N-dimethyl-p-toluidine (DMT) or BPO/4-N,N-dimethylamino phenethyl alcohol (DMPOH) redox system at 378C. 13 It was found that the polymerization rate (R p ) and molecular weight of the prepared polymer depended on both the BPO and amine concentrations. When the product of these concentrations was kept constant, the maximum rate and lowest molecular weight were obtained with a slight molar excess of BPO (BPO/amine 5 1.6).…”