Ali Boztuğ

Effects of different high alkyl methacrylate monomers on tensile bond strength between resilient liner and acrylic resin

Abstract In the present study, tensile bond strength between an acrylic resin and a resilient denture liner, Molloplast B, was studied. To enhance the bonding capacity between these materials, acrylic resin surface was modified using ethyl methacrylate, iso-butyl methacrylate or tert-butyl methacrylate monomers. Changes on the modified surfaces were investigated by Fourier transform infrared spectroscopy with attenuated total reflectance. Only the modifications by iso-butyl methacrylate application appeared to have an increasing effect on the tensile bond strength value. Ethyl methacrylate and tert-butyl methacrylate, however, had a lowering effect on this value.

Bond Strength of a Silicone Soft Lining Material to Poly(methyl methacrylate) Resin Treated with Maleic Anhydride and its Terpolymers

This study investigated the effectiveness of surface treatment of Poly (methyl methacrylate) (PMMA) denture base resin on tensile bond strength between PMMA/silicone-based soft liner. A total of 25 specimens were fabricated and assigned into five groups (n = 5). The surfaces of PMMA were treated with maleic anhydride, maleic anhydride-styrene-vinyl-acetate, n-butylmaleate-styrene-vinyl-acetate, or n-pentamaleate-styrene-vinyl-acetate prior to Primo adhesive primer application and silicone liner placement. The Primo adhesive primer on applied group untreated dentuse base resin served as control. The tensile test was performed using a universal testing machine. Fractured surfaces were observed under Scanning Electron Microscopy (SEM) and spectroscopic interpretation of the interfaces was done by Fourier Transform Infrared (FTIR). Test results showed that surface treatment increased interfacial strength giving the highest value for n-butylmaleate-styrene-vinyl acetate treated group. SEM micrographs revealed that the specimens with n-butylmaleate-styrene-vinyl-acetate and n-penta maleate-styrene-vinyl-acetate terpolymers underwent cohesive failure. FTIR analysis indicated secondary interactions such as hydrogen bonding, possibly on acrylic resin surfaces, caused by the use of maleic anhydride and its terpolymers, and the adhesive.

Investigation of miscibility of poly(vinyl chloride) with poly(ethylene-co-vinyl acetate) by viscosimetric method

Abstract In this study, miscibility of blends of poly(vinyl chloride) with poly(ethylene-co-vinyl acetate) (PVC/EVA) have been investigated in tetrahydrofuran (THF) by a viscosimetric method. In order to study the miscibility of the polymer pair in solution, the interaction parameter, Δb, obtained from the modified Krigbaum and Wall theory was used. Polymer blends with EVA content of 10%, 20%, 40%, 60% and 80% at a concentration of 6.0 g dm−3 were prepared. Turbidity measurements and the values of the relative viscosities of each of the polymer solutions and their blends were determined. In consequence of the study, it was observed that PVC and EVA miscible each other as limited.

Effects of some methacrylate monomers used as liquid component on tensile and flexural strengths of poly(methylmethacrylate) denture base resin

Abstract The present study was conducted to observe the effect of different monomers on tensile and flexural strengths of poly(methyl methacrylate) (PMMA) denture base resin when they were used as a liquid component. A conventional heat cured denture base polymer powder was mixed with ethyl, isobutyl and tert-butyl methacrylate monomers respectively. After the polymerisation process was completed, the tensile and flexural strengths of these specimens were compared with those of PMMA resin specimens polymerised with methylmethacrylate monomer (MMA). Tensile specimens were prepared in a dumbbell shape using a stainless steel mould constructed according to ASTM D638M-91a. Rectangular flexural specimens were prepared as designated in ASTM D790M-92. Each group was subjected to tensile strength and flexural strength tests using a universal testing machine at a crosshead speed of 50 mm min−1. In addition to mechanical tests, the structural change in the acrylic resin specimens prepared with different monomers was observed using a Fourier transform infrared spectrometer with attenuated total reflectance unit. The differences in the tensile strengths of all specimens were not found to be statistically significant (p>0·05), whereas the flexural strengths showed statistical differences among the groups tested (p<0·05). In the results of the tests performed, it was reached that the flexural and tensile strengths of acrylic resins obtained by various methacrylate monomers were different. It can be said that these acrylic resins can be used for various aims in different fields and in the dentistry field.

Modification and characterization of maleic anhydride-styrene-methyl metacrylate terpolymer using various alcohols

In this study, the anhydride units in maleic anhydride-styrene-methyl metacrylate terpolymer (MA-St-MMA) were reacted with n-propyl, n-butyl, n-pentyl and n-benzyl alcohols, and the ester derivatives of MA-St-MMA terpolymer were obtained. These were named n-alkyl maleate ester derivatives, abbreviated as nPrMA-St-MMA, nBuMA-St-MMA, nPnMA-St-MMA and nBzMA-St-MMA. The aim of this study was to obtain more elastic polymers by replacement with the maleic anhydride units in MA-St-MMA terpolymer of alkyl groups having a linear chain structure. All the polymers synthesized were characterized by FT-IR, TMA, the solvent definition, the number of esters and solution viscosity. The TMA experiments of all the polymers were studied under increasing and temperature. All these studies have showed that the n-alkyl maleate ester derivatives are more elastic than original MA-St-MMA terpolymer.

Chemical modification and thermal characterisation of poly(allylpropionate-alt-maleic anhydride) copolymer modified by hexamethylenediamine

Abstract The copolymers of maleic anhydride (MA) are frequently used as a reactive polymer in the preparation of functional polymers in which the active agents consisting of amino or hydroxy groups can be linked to them via ring opening reactions. In the present paper, allylpropionate-alt-maleic anhydride (MA-AP) copolymer was modified by hexamethylenediamine (HMDA) to obtain poly(maleamidic acid-allylpropionate) copolymer (MAA-AP) opening the maleic anhydride ring in the MA-AP copolymer. Next, maleimide-allylpropionate (MI-AP) copolymer was obtained by heating MAA-AP copolymer. The MA-AP, MAA-AP and MI-AP copolymers were characterised by Fourier transform infrared spectroscopy (FTIR). The thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques were used for the thermal characterisation of all the polymers. In conclusion, much more thermally stable copolymers have been obtained due to replacement of maleimide and maleamidic acid groups instead of anhydride units.

Investigation of effects of reactive copolymer containing maleic anhydride on thermomechanical properties of ternary blends of poly(methyl metacrylate) (PMMA)

Abstract In the present paper, the effects of reactive copolymer containing maleic anhydride on the thermomechanical properties of poly(methyl metacrylate) (PMMA) were investigated. Maleic anhydride–styrene (MA–St) and aniline maleamidic acid–styrene copolymers (AnMAA–St) were used as reactive copolymers. Multicomponent blends such as PMMA/MA–St/AnMAA–St were prepared and thermomechanical characterisation of these blends was performed by thermomechanical analysis method (TMA). The blends were prepared by changes of the weight ratios of MA–St and AnMAA–St copolymers in the blends. PMMA contents in all the blends are fixed at a weight of 75%. Consequently, it is clear that MA–St copolymer can be used for changes of the thermomechanical properties of PMMA.