• 폴리머
• /
• 제30권3호
• /
• pp.230-237
• /
• 2006

단량체로 methyl methacrylate, n-butyl acrylate, 2-hydroxyethyl acrylate와 도막물성 향상 및 가교밀도를 극대화시켜 줄 관능성 단량체인 acetoacetoxyethyl methacrylate (AAEM)를 반응시켜 4원공중합체인 고형분 80%의 아크릴수지 (HSA-98-20, HSA-98-0, HSA-98+20)를 합성하였다. AAEM 성분이 함유된 아크릴수지의 점성도는 $1420\sim5760cps$, 수평균분자량 $2080\sim2300g/mol$, 다분산도 $2.07\sim2.19$ 및 전환율 $88\sim93%$이었다. 고형분 80%인 아크릴수지와 이소시아네이트 경화제를 상온에서 경화시켜 하이솔리드 도료(HSA-98-20C, HSA-98-0C, HSA-98+20C)를 제조하고 도막시편을 제작하여 각종 물성 시험을 수행한 결과, 제조된 하이솔리드 도료내에 AAEM 도입 전후의 도막물성이 비교실험에서 AAEM 도입후에 내마모성과 내용제성이 증진됨으로써 자동차 상도용 도료에의 적용이 가능케 되었다. 또한 점탄성 측정에 의한 도막의 경화거동에서 HSA-98+20C > HSA-98-0C > HSA-98-20C의 순서로 경화가 빨리 진행됨으로써, 유리 전이 온도 값의 증가함에 따라 경화속도가 빨라짐을 알 수 있었다.

• The Journal of Advanced Prosthodontics
• /
• 제9권6호
• /
• pp.453-462
• /
• 2017

PURPOSE. The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/ food intake. MATERIALS AND METHODS. Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (${\phi}=10$ mm and d=2 mm) under different extraction conditions ($37^{\circ}C$ for 24 hours, $70^{\circ}C$ for 24 hours, and $121^{\circ}C$ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS. Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP ($70^{\circ}C$) and AT ($121^{\circ}C$) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF ($37^{\circ}C$) (P<.05). CONCLUSION. Extracts obtained from six materials under different extraction conditions ($37^{\circ}C$, $70^{\circ}C$, and $121^{\circ}C$) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.

• The Journal of Advanced Prosthodontics
• /
• 제7권2호
• /
• pp.98-107
• /
• 2015

PURPOSE. The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS. 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS. Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION. Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.

• 대한치과보철학회지
• /
• 제40권3호
• /
• pp.236-245
• /
• 2002

The acrylic resin was first introduced as denture base materials in 1937 and it is commonly used for denture base fabrication nowadays. Three different curing cycles (Conventional curing cycle, short curing cycle and long curing cycle) and three commercially available heat-activated acrylic resins (Vertex RS, Lucitone 199 and ProBase Hot) were investigated to find the curing cycle and material that showed the minimum shrinkage of the resin during polymerization process. A brass master mold was fabricated and duplicated by additional silicone impression material. Stone molds were made by pouring of type III dental stone (SILKY-ROCK YELLOW, Whip-Mix, Louisville, Kentucky). It was embedded in the flask. Strain gauge and thermocouple were embedded in the specimen. Strain gauge and thermocouple were connected to signal conditioning amplifier and data was recorded by pre-programmed software. The parameters ESmax (Maximum expansion strain), Sb (Strain measured just before deflasking procedure), Sa (Strain measured just after deflasking procedure) and Sf (Strain measured at the end of the experiment) were measured. ${\Delta}$S was calculated from Sb and Sa (${\Delta}$S=Sb-Sa). In the experiment concerned about materials, the parameters 90-ESmax (Maximum expansion strain measured during early 90 minutes of curing procedure), 180-ESmax (Maximum expansion strain measured from 90 minutes to 180 minutes), Sb, Sa, ${\Delta}$S and Sf were measured and the following conclusions were made. 1. The ESmax value of conventional curing cycle showed the largest value and the 180-ESmax value of Lucitone 199 showed the smallest value. 90-ESmax values showed no significant difference (p<0.05). 2. ${\Delta}$S values of conventional curing cycle showed the positive values. ${\Delta}$S values of short curing cycle and long curing cycle showed the negative values. All three materials cured by conventional curing cycle showed the positive values. 3. The Sf values of long curing cycle and ProBase Hot (cured by conventional curing cycle) showed the smallest values.

• 폴리머
• /
• 제24권4호
• /
• pp.520-528
• /
• 2000

본 연구는 고형분 70%인 하이솔리드 아크릴 수지 (BMHA)를 합성하여, 환경친화성 도료인 하이솔리드 아크릴/폴리이소시아네이트 도료(BNHS)에 적용하고 그의 도막특성을 살펴본 것에 그 의의가 있다. BMHA는 새로운 형의 단량체로서 acetoacetoxyethyl methacrylate (AAEM)을 도입하고 여기에 n-butyl acrylate, methyl methacrylate 및 2-hydroxyethyl acrylate를 4원공중합시켜 얻었다. BMHA 합성에 있어서 T$_{g}$ 값이 낮을수록, AAEM의 양이 많을수록 각각 높은 전환율을 나타내었고, T$_{g}$값 고정하의 OH 값 변화에 따른 전환율은 큰 차이가 없었다. BMHA와 폴리이소시아네이트를 상온경화시켜 하이솔리드 BNHS 도료를 제조하고서 자동차 상도용 도료로서의 적합성 여부를 알아보기 위하여 도막물성 시험을 한 결과, BNHS내에 AAEM 도입 전후의 도막물성 비교시험에서 AAEM 도입후에 내마모성과 내용제성이 향상됨으로써 자동차 상도용 도료로서의 응용가능성을 보여주었다.다.

• Tribology and Lubricants
• /
• 제14권4호
• /
• pp.72-78
• /
• 1998

In this work, the effects of binder materials on the tribological behavior were experimentally evaluated for air curable MoS$_2$bonded film lubricants. The binders tested were basically alkyd and acryl based resins, and also were modified by nitro-cellulose in various weight percentages. Effects on the binder ratio to solid lubricants and the molecular weight of binders were also investigated in all aspects of the tribological behavior. For the tests, LFW-1 and Falex tester were used to measure mainly the endurance life and load carrying capacity of bonded lubricants. Results showed that lubricants of methacrylic resin has the better performance than those of other resins, and also the properties of lubricants both of alkyd and acrylic resins could be improved by modification with nitro-cellulose. It was also shown that the optimum ratio of nitro-cellulose related closely to the binder material and the testing machine.

• 한국응용과학기술학회지
• /
• 제17권4호
• /
• pp.233-239
• /
• 2000

To prepare an environmental friendly high-solid coatings an acrylic resin containing 80% of solid content was synthesized by addition polymerization of caprolactone acrylate, n-butyl acrylate, ethyl methacrylate, and 2-hydroxyethyl methacrylate. The conversion was $78{\sim}93%$ and the prepared resin's physical properties are as follows: viscosity, $212{\sim}3424cps: $M_{n}$ $1740{\sim}2400$. There was a trend that viscosity and molecular weight of the resin increased with Tg, but no direct proportionality was observed.

• 폴리머
• /
• 제26권5호
• /
• pp.615-622
• /
• 2002

전보에서 합성된 안료분산용 및 희석용 실리콘/아크릴수지의 배합비를 중량비율 4 : 6, 3 : 7 및 2 : 8로 다양화하여 내후성 도료를 제조하였다. 제조된 내후성 도료로써 내후성에 속하는 각종 도막물성 시험을 행한 결과 실리콘 성분함량이 증가할수록 열적 안정성, 도막의 일반물성 및 내후성 등이 전반적으로 향상되는 결과를 보여주었으며, 3종류의 수지 배합비 중 2 : 8의 배합비가 적정선임을 알았다. 또한 실리콘 성분 30 wt% 함유한 도료는 고내후성 도료로서 거동함이 밝혀졌다

• 대한치과보철학회지
• /
• 제39권1호
• /
• pp.49-57
• /
• 2001

The use of autopolymerizing-cured resin and light-cured resin for direct introral relining of complete and partial dentures has been popular. The purpose of this investigation was to determine the surface characteristics of autopolymerizing-cured reline resins(Tokuso rebase, Mild rebaron, Meta base) and light-cured reline resin(Mild rebaron LC). Acrylic resin slab specimens(1.0cm in diameter at the bottom, and 0.3cm high) were made against glass according to the instructions of the manufacturer following normal procedures for each of direct reline resins and examined the surface characteristics by use of surface profilometer and the other specimens which were made intraorally for each of direct reline resins were examined by use of scanning electron microscopy. The results were as follows : 1. Each surface roughness(Rz) of hard relin resins was $0.14{\pm}0.04{\mu}m$ in Tokuso rebase, $0.37{\pm}0.11{\mu}m$ in Mild Rebaron, $0.79{\pm}0.44{\mu}m$ in Mild Rebaron LC, $6.36{\pm}3.40{\mu}m$ in Meta base. There were significant differences between the surface roughness of Meta base and those of other reline resins(p<0.05) 2. The generation of porosity was the most in Tokuso Rebase and followed by Meta base, Mild Rebaron and Mild Rebaron LC in the order respectively. 3. Light-cured reline resin(Mild rebaron LC) was denser in surface than any other autopolymerizing-cured reline resins. Tokuso rebase and Mild rebaron was denser than Meta base. Conclusively, light-cured reline resin(Mild rebaron LC) had less porosity and better surface density than any other autopolymerizing-cured reline resins.

• 대한치과보철학회지
• /
• 제31권4호
• /
• pp.523-531
• /
• 1993

The purpose of this study was to investigate the color change of denture base resins by coffee. Denture base resins for this study were Triad VLG Denture Base (Dentsply, York Div. U.S.A.), Premium Super-20 (Lang Dental Mfg. Co., Inc., U.S.A.) for denture base, Toughron Rebase (Miki Chemical Prod., Kyoto, Japan), Jet Repair Acrylic (Lang Dental Mfg. Co., Inc., U.S.A.), Triad Reline (Dentsply, fork Div. U.S.A.) and Tokuso Rebase (Tokuyama Soda Co., Ltd., Japan) for denture rebase. Twenty specimens of each denture base resin were made and polished. The color of specimens was measured by colorimeter (Model Tc-6FX, Tokyo Denshoku Co. Japan), and they were stored in coffee for three weeks and then color changes were measured. The obtained results were as follows : 1. The L*, a*, b* and the E*ab values of all denture base resins were changed after three weeks. 2. The amount of color change on L*, a*, b* and the E*ab value of each specimens showed different patterns. 3. The b* values of Triad Reline materials were changed more than the other materials. 4. The E*ab values of Triad Denture Base materials were changed more than the other materials.