AIM The purpose of this study was to evaluate and compare the flexural strength of commercially available acrylic (trevalone) and modified polymethylmethacrylate (PMMA). MATERIALS AND METHODS Four groups were tested; Group 1- control group regular MMA, group 2-2% methacrylic acid, 88% MMA, group 3-16% methacrylic acid, 84% MMA group 4- 20% methacrylic acid, 80% MMA 15 resin specimens of each ...

the feasibility of extractive reaction of methacrylic acid from aqueous solution using a quaternary amine, tri–octyl methyl ammonium chloride (tomac) as an extractant, was studied. the diluents chosen in the present work belong to different chemical classes, n–butyl acetate, carbon tetrachloride, isoamyl alcohol, methyl isobutyl ketone, and toluene. the effect of initial acid concentration in t...

We studied the allergic reaction of guinea pigs to glyceryl methacrylate (GM), hydroxyethyl methacrylate (HEMA) and meso-erythritol methacrylate (EM), which are used as dentin primers. On the 18th day of the application test, when macroscopic investigation revealed an inflammatory reaction, the methacrylic acid-treated group showed marked eschar formation in comparison with the control group. I...

The emulsion polymerization of styrene was investigated using polystyrene-b-[polystyrene-r-poly(methacrylic acid)] amphiphilic block-random copolymers (BRCs) different compositions as stabilizers. These stabilizers with molar masses <20,000 g/mol, which possess unique dispersion behaviour (i.e., self-assembly low aggregation numbers) when dissolved in aqueous medium at alkaline pH, were prepare...

conclusions it was shown that combination of pectin and eudragits can relatively control drug release in the upper gi. on the other hand, pectin degraded in the presence of pectinase and formulations were susceptible to the colonic media. results it was shown that in the presence of pectin, formulations without erl had a relative resistance to drug release in sgf. pellets containing pectin and ...

The dissociation of t-butyl methacrylate-methacrylic acid copolymers in dimethyl sulfoxide was analyzed by a nonaqueous potentiometric titration technique. The negative logarithm of the dissociation constant of the monomer unit of a methacrylic acid (MAA) monotonously increased with the increasing degree of dissociation corresponding to the titrant/MAA amount ratio, and was highly influenced by...

Graft copolymers of poly (ethylene glycol) with poly (methacrylic acid) were prepared by reaction of poly (ethylene glycol) methacrylate macromonomer with methacrylic acid in the presence of tetraethylene glycol dimethacrylate as a crosslinking agent. The materials were swollen in aqueous solutions with the pH ranging from 1.5 to 12.0. Dynamic swelling studies were performed. The swelling rates...

Compositions of different molar ratios of polymethylmethacrylate-co-methacrylic acid (PMMA-co-MAA) were synthesized via free-radical polymerization. Polymer coated surfaces have been produced on silicon wafers. Coated samples were analyzed by atomic force microscopy (AFM). The results have shown that the roughness of the surfaces have increased by increasing the molar ratio of monomer methacryl...

We report on the synthesis and application of a new hydrogel based on a methacrylate substituted polyphosphazene. Through ring-opening polymerization and nucleophilic substitution, poly[bis(methacrylate)phosphazene] (PBMAP) was successfully synthesized from hexachlorocyclotriphosphazene. By adding PBMAP to methacrylic acid solution and then treating with UV light, we could obtain a cross-linked...