AIMS AND OBJECTIVES To evaluate and compare the effect of fiber reinforcement on the dimensional changes of heat-cured poly (methyl methacrylate) resin after processing and immersion in water. MATERIALS AND METHODS Three different heat-cure resins were selected for the present study: (1) Nonreinforced heat-cure methyl methacrylate resin, (2) High Impact heat-cured methyl methacrylate resin an...

Transparent and heat-resistant poly(methyl methacrylate) copolymers were synthesized by bulk polymerizing methyl methacrylate (MMA), isobornyl methacrylate (IBMA), and methacrylamide (MAA) monomers. Copolymerization was performed using a chain transfer agent to investigate the molecular weight changes of these copolymers, which exhibited advantages including a low molecular weight distribution,...

Modified xanthan gum is often used in a variety of industries such as pharmaceuticals, the food industry, and oil industry. The use modified emulsions can solve two problems, stabilize thicken. This work dedicated to study oil-in-water emulsion stability. continuous phase consists aqueous solutions (XG-g-MMA), alkyl polyglycoside (APG), silicon dioxide nanoparticles (SiO2), kerosene was dispers...

Thiol-ene systems demonstrate numerous advantageous polymerization properties in regards to rapid curing, high conversion, minimal oxygen inhibition, and reduced shrinkage stress. However, one of the drawbacks of thiol-ene systems is that commercially available monomers are not able to achieve the mechanical properties required for use as dental restorative materials. Methacrylate systems on th...

A methacrylic terpolymer system with non-fouling interfacial properties was synthesized by the random copolymerization of hexyl methacrylate, methyl methacrylate and sulfobetaine methacrylate (a monomer bearing a zwitterionic pendant group). Polymers were synthesized from feeds containing 0-15 mol.% of the zwitterion-containing methacrylate. Proton nuclear magnetic resonance verified the incorp...

To ascertain the relationship between the physical properties of polymer supports and the observed response of luminescence-based oxygen sensors, a quenching-based method was developed to measure oxygen diffusion in polymers. The method offers advantages over existing quenching-based techniques since it allows a simple correction for films of high optical density, and the computations do not as...

(2S)[3,3,3-2H3]Isobutyrate, sodium salt, was synthesized and administered intraperitoneally to normal rats. Urinary organic acids were analyzed by gas chromatography-mass spectrometry. 3-Hydroxyisobutyric acid excreted by the rats, analyzed as both a methyl and an isopropyl ester, was found to be enriched almost exclusively with two deuteriums in the hydroxymethyl moiety of the molecule. This r...

Tissue from 73 chick embryos incubated for periods between 1 and 13 days has been studied. Before fixation each specimen was staged according to the normal table of Hamburger & Hamilton (1951). The tissue was fixed either in osmium tetroxide, or in potassium permanganate (Luft, 1956). In either case the pH was buffered to 7-4 with sodium veronal (Palade, 1952) and fixation was at 0° C. In the e...

Taste masked microspheres of ornidazole were prepared using amino alkyl methacrylate copolymers (Eudragit E-100) by solvent evaporation technique. Taste assessment of these microspheres was done by both spectrophotometric taste evaluation technique and panel testing. Compressed tablets of taste masked ornidazole microspheres which rapidly disintegrated in the oral cavity were prepared using mic...