title: Influence of selected components on crosslink density in polymer structures.
abstract: Bifunctional methacrylates polymerize to form crosslinked polymer structures which may be characterized by the quantity of remaining double bonds and by the crosslink density. This study investigated the influence of composition variation on the crosslink density of model methacrylate polymers. It was hypothesized that addition of a monofunctional monomer would reduce crosslink density and that compositions giving rise to many centers of polymer growth would result in increased crosslink density. Unfilled resins with varying content of BisGMA, TEGDMA, a monofunctional monomer, camphoroquinone, and amine were polymerized by visible light irradiation. After polymerization, the quantity of remaining double bonds and the Wallace hardness were determined. Polymer softening upon storage in ethanol was taken as a measure of the crosslink density. After ethanol storage, the relationship between hardness number and amount of monofunctional monomer showed a minimum. At same quantity of remaining double bonds, a high content of camphoroquinone compared to amine resulted in reduced softening in ethanol. Composition influenced not only remaining double bonds but also the crosslink density of the resulting polymer structures.
authors.affiliation: Department of Dental Materials, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Denmark. ea@odont.ku.dk
authors.forename: E
authors.initials: E
authors.lastname: Asmussen
authors.forename: A
authors.initials: A
authors.lastname: Peutzfeldt
mesh_terms: D000704:Analysis of Variance; D000814:Aniline Compounds / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003188:Composite Resins / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D006244:Hardness; D006801:Humans; D008027:Light; D008689:Methacrylates / Q000737:chemistry*; D020366:Methylmethacrylate / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012044:Regression Analysis; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013223:Statistics as Topic; D013729:Terpenes / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D003188:Composite Resins; D008689:Methacrylates; D011108:Polymers; D011109:Polymethacrylic Acids; D012997:Solvents; D013729:Terpenes; C020946:triethylene glycol dimethacrylate; D020366:Methylmethacrylate; D000431:Ethanol; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C048339:camphoroquinone; D002244:Carbon; D019904:Polymethyl Methacrylate; C076186:3-(N-methylanilino)propiononitrile