[Studies on the dental methacrylic resins (part 4). Flow properties and curing times of the pour methacrylic resins (author's transl)].
Flow properties and curing times of the pour resins consisted of polymethyl methacrylate and methyl methacrylate were investigated by the viscosity and the temperature measurements. The polymers with various article sizes and molecular weights and the monomer with 0.005 per cent hydroquinone were used the pour resins respectively. The initiator system of benzoyl peroxide--N, N-dimethyl-p-toluidine was used for the polymerization. The results were as follows: 1) The viscosities of the pour resins were increased with the time elapsed. That was for reasons of physical phenomenon, that is, dissolution of polymer into monomer. The logarithmic viscosities increased linearly in proportion to the time elapsed. 2) The viscosities of the pour resins were increased by the reduction of the particle size of the polymer and by the increase of the molecular weight of the polymer. 3) The curing times of the pour resins were reduced by the increase of the concentrations of benzoyl peroxide and N, N-dimethyl-p-toluidine, and by the reduction of the particle size and the molecular weight of the polymer respectively.
D000180:Acrylic Resins; D003764:Dental Materials; D008768:Methylmethacrylates; D012212:Rheology; D013997:Time Factors; D014783:Viscosity
D000180:Acrylic Resins; D003764:Dental Materials; D008768:Methylmethacrylates