A versatile synthetic strategy has been developed which enables the facile incorporation of cleavable functional groups, i.e., esters, thioesters, and disulfides, into the carbon-carbon backbone of vinyl-based polymers. Through the synthesis of novel cyclic monomers, RAFT-mediated radical ring-opening copolymerizations with traditional vinyl monomers such as methyl methacrylate, N,N-dimethylami...

It has been found that tissues fixed for electron microscopy and dehydrated in acetone can be embedded in mixtures of n-butyl methacrylate and polyester resin. Activation with 1 per cent tert-butyl hydroperoxide followed by 12 to 48 hours at 60 degrees C produces blocks that section well with glass knives. The ribbons are cleared of methacrylate by heat (200-250 degrees C for 1 hour) and/or imm...

Alkyl carboxylate-modified layered double hydroxides (LDH) were prepared and used as nanofillers for poly(methyl methacrylate) (PMMA) and polystyrene (PS). The LDH intercalated with long-chain linear alkyl carboxylates (CH3(CH2)nCOO , n 1⁄4 8, 10, 12, 14, 16, 20) were prepared via anionic exchange of MgAl–nitrate, showing a systematic increase in basal spacing with longer alkyls. MgAl–undecenoa...

Taste of a pharmaceutical formulation is an important parameter for the effectiveness of pharmacotherapy. Cetirizine dihydrochloride (CET) is a second-generation antihistamine that is commonly administered in allergy treatment. CET is characterized by extremely bitter taste and it is a great challenge to successfully mask its taste; therefore the goal of this work was to formulate and character...

BACKGROUND To evaluate marginal microleakage of two composite resins - a methacrylate- and a silorane-based submitted to different polymerization techniques and thermocycling. MATERIAL AND METHODS Ninety-six class V cavities were prepared in sound human molars and restored under different polymerization and thermocycling regimens. The adhesive systems employed were Adper Scotchbond Multipurpo...

objectives: the aim of this study was to assess and compare the water sorption and flexural strength of thermoplastic and conventional acrylic resins. materials and methods: water sorption and flexural strength were compared between a thermoplastic modified polymethyl methacrylate (pmma) denture base resin (group a) and a heat-polymerized pmma acrylic resin (group b) as the control group (n=10)...

polymethyl methacrylate (pmma), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. this study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of com...

objective roughness is the main parameter in interlocking bonding mechanism. yet there is no model designed to evaluate the effect of surface roughness on adhesion of coating materials in pharmaceutical sciences. materials and methods in this study polymethyl metacrylate spherical beads with different sizes were poured into 10 mm mold, then it was pressed by hand screw and finally heated to 141...

the glass transition temperature of several pvac(1)-b-poly(ma-co-mma) (2) terpolymers with different fractions of methyl acrylate (ma) and methyl methacrylate (mma) repeating units in random copolymer (block 2) were calculated with barton, kwei and topological equations. the calculation was on the basis of the correlation between the fraction of repeating units in random copolymers and theoreti...

The surface-initiated ATRP of benzyl methacrylate, methyl methacrylate, and styrene from magnetite nanoparticle is investigated, without the use of sacrificial (free) initiator in solution. It is observed that the grafting density obtained is related to the polymerization kinetics, being higher for faster polymerizing monomer. The grafting density was found to be nearly 2 chains/nm2for the rapi...