title: Influence of 4-methacryloxyethyl trimellitic anhydride on composites subjected to hygrothermal cycling.
abstract: Pastes were made by spatulating a hydroxyapatite powder into triethylene glycol dimethacrylate (TEGDMA) that contained benzoyl peroxide. For comparison, similar pastes included 5 wt-% 4-methacryloxyethyl trimellitic anhydride (4-META) in the TEGDMA. Composites were made by heating at 120 degrees C under pressure. Inclusion of 4-META reduced the rate of diffusion of water by about one-third, at 27 degrees C. Also after thermal cycling in water, inclusion of 4-META decreased the fractional drop in compressive strength by about one-half. Examination of fracture surfaces indicated that inclusion of 4-META improved the wetting of filler particles and gave more coherent composites. All these findings are consistent with the view that 4-META acts as a coupling agent.
mesh_terms: D000179:Acrylates; D001585:Benzoyl Peroxide; D055598:Chemical Phenomena; D002621:Chemistry; D003188:Composite Resins; D004058:Diffusion; D004355:Drug Stability; D017886:Durapatite; D006358:Hot Temperature; D006882:Hydroxyapatites; D007700:Kinetics; D008689:Methacrylates; D010545:Peroxides; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D013314:Stress, Mechanical; D013329:Structure-Activity Relationship; D014867:Water
chemical_list: D000179:Acrylates; D003188:Composite Resins; D006882:Hydroxyapatites; D008689:Methacrylates; D010545:Peroxides; D011109:Polymethacrylic Acids; D014867:Water; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C034139:4-methacryloxyethyltrimellitic acid anhydride; D017886:Durapatite; D001585:Benzoyl Peroxide