• The Journal of Advanced Prosthodontics
• /
• v.8 no.4
• /
• pp.285-289
• /
• 2016

PURPOSE. This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS. Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (${\alpha}$=.05). RESULTS. The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P<.05) when compared within the same brand. Among the surface treatment groups of each brand, there were no significantly different tensile bond strengths between the MF-MA groups and the MMA 180 second group (P>.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05). CONCLUSION. 15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.310-313
• /
• 2000

Polyaniline Emeraldine Base (PANI EB) polymerized by chemical oxidative polymerization was doped with Camphorsulfonic Acid(CSA). Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) solutions were solved in organic solvents and sonificated at the room temperature for different solvents in PANI-CSA ES solution and sonification time. PANI-CSA ES solutions was coated on PET films using bar coater. 1-Step oxidatively-polymerized Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) was solved in m-cresol:chloroform 1:1 co-solvents and their solution was bar-coated on PET film. The surface resistivities of these coated films were measured, The surface resistivity of PANI-CSA ES solution in m-cresol:chloroform 1:1 co-solvent system was 5${\times}$10$^2$$\Omega$/$\square$.

• Proceedings of the Korean Fiber Society Conference
• /
• 1994.04a
• /
• pp.72-72
• /
• 1994

• Fibers and Polymers
• /
• v.5 no.2
• /
• pp.89-94
• /
• 2004

N-Vinylcarbazole (VCZ) was solution-polymerized in tetrahydrofuran (THF) at 25, 35, and $45^{\circ}C$ using a room temperature initiator, 2,2'-azobis(2,4-dimethylvaleronitrile) (ADMVN); the effects of amount of solvent, polymerization temperature, and initiator concentration were investigated. On the whole, the experimental results corresponded to predicted ones. Room polymerization temperature using ADMVN proved to be successful in obtaining poly(N-vinylcarbazole) (PVCZ) of high molecular weight with small temperature rise during polymerization, nevertheless of free radical polymerization by azoinitiator. The polymerization rate of VCZ in THF was proportional to the 0.47 power of ADMVN concentration. The molecular weight was higher and the molecular weight distribution was narrower with PVCZ polymerized at lower temperatures. For PVCZ prepared in THF at $25^{\circ}C$ using ADMVN concentration of 0.00005 mol/mol of VCZ, weight-average molecular weight of 221,000 was obtained, with polydispersity index of 2.05, and degree of lightness converged to about 99%.

• Journal of Integrative Natural Science
• /
• v.6 no.4
• /
• pp.215-219
• /
• 2013

In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4-ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly-urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that a well prepared APS-SAM on a glass surface treated with water vapor/Ar plasma is very useful for uniform coating of FeCl3 and DUDO mixed oxidant solution, regardless of HF treatment. On the other hand, a bare glass surface without APS-SAM but treated with HF and water vapor/Ar plasma generally led to a very poor oxidant film. As a result, PEDOT films vapor phase-polymerized on APS-SAM surfaces are far superior to those on bare glass surfaces in the quality and electrical characteristics aspects.

• Korean Journal of Materials Research
• /
• v.8 no.7
• /
• pp.616-620
• /
• 1998

Zn_{0.994}Mn_{0.006}Ga_2O_4$ green phosphor powders were synthesized using polymerized complex and solution combustion methods, and their powder and luminescence properties were characterized by XRD, SEM, BET, PL, etc. The properties were compared with those of the powders prepared by a solid state reaction method. The powders prepared by polymerized complex and solution combustion methods showed only a single spinel phase at 50$0^{\circ}C$ and 40$0^{\circ}C$, respectively. Their particle sizes were smaller than that of a solid state reaction method. Emission intensity of the phosphor powders prepared by both methods were highest at 90$0^{\circ}C$ and 40$0^{\circ}C$, respectively.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.23 no.4
• /
• pp.899-905
• /
• 1996

For the purpose of evaluation of microleakage of class V resin restoration, 64 extracted bovine teeth were filled with two kinds of light curing composite resins(Z-100, Clearfil) and polymerized with 40 seconds of visible light and with 10 seconds of argon laser. After 1000 thermocycling($5^{\circ}C/55^{\circ}C$), specimens were placed in 1 % methylen blue dye solution for 72 hours in $37^{\circ}C$ water bath. The specimens were sectioned at center of filling body and the degree of dye penetration was observed with a stereomicroscope. The following results were obtained, 1. Differences of the microleakage of resin restorations polymerized with 10 seconds of argon laser and 40 seconds of visible light were statistically insignificant. 2. There was more microleakage in Z-100 than clearfil and there was a statistical significancy (p<0.05).

• Applied Chemistry for Engineering
• /
• v.19 no.3
• /
• pp.287-294
• /
• 2008

Molecularly imprinted polymer (MIPs) membranes were prepared by UV polymerization to separate racemates with opposite physiological activity, and then its separation selectivity of racemates was carried out. Likewise, their properties were examined. Polycarbonate (PC) membrane was polymerized as small spot form in pore inner wall, but anodisc (AD) membrane was polymerized as film form with thickness 500~700 nm onto the membrane surface. Also the study on the separation selectivity of prepared MIPs membranes was carried out in L-Tryptophane (Trp) racemate solution. The results showed that AD MIPs membrane polymerized as a film form, which was achieved by solution polymerizaion consisting of over 90% cross-linking agent (ethylene glycol dimethacrylate; EGDMA) and under 30% dispersing agent (methanol; MeOH), had predominant 3.5 selectivity.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.04a
• /
• pp.13-16
• /
• 2003

Vinyl acetate monomer can be polymerized through bulk, solution, emulsion, and suspension polymerization processes. However, in the preparation of PVA from bulk or solution polymerization, there are several technical limitations for obtaining high yield and high molecular weight simultaneously. Thus, the improvement of polymerization method is necessary to prepare the PVA with high yield and high molecular weight because that the difficulty in control of high viscosity and in removal of the heat of polymerization, which might lead to side reactions like branching. (omitted)

• Bulletin of the Korean Chemical Society
• /
• v.17 no.3
• /
• pp.257-262
• /
• 1996

p-(2-Vinyloxyethoxy)benzylidenemalononitrile 2 and methyl p-(2-vinyloxyethoxy)benzylidenecyanoacetate 3 was prepared by the condensation of p-(2-vinyloxyethoxy)benzaldehyde 1 with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 2 and 3 polymerized quantitatively with radical initiators in γ-butyrolactone solution at 65 ℃. The trisubstituted terminal double bond participated in the vinyl polymerization and radical polymerization of 2 and 3 led to swelling polymers 4 and 5 that were not soluble in common solvents due to cross-linking. Under the same polymerization conditions ethylvinyl ether polymerized well with model compounds of p-methoxybenzylidenemalononitrile 6 and methyl p-methoxybenzylidenecyanoacetate 7, respectively, to give 1:1 alternating copolymers 8 and 9 in high yields. Polymers 4 and 5 showed a thermal stability up to 300 ℃ without any characteristic Tg peaks in DSC thermograms. Alternating copolymers 8 and 9 were soluble in common solvents such as acetone and DMSO, and the inherent viscosities of the polymers were in the range of 0.36-0.74 dL/g. Films cast from acetone solution were cloudy and tough and Tg values obtained from DSC thermograms were in the range of 59-60 ℃.