• 한국산학기술학회논문지
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• 제14권11호
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• pp.5745-5751
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• 2013

본 논문은 monomer에서 결합증진에 많은 역할을 하는 MMA와 TEGDMA의 농도별 표면 처리와 silane coupling agent로 표면 처리한 것이 의치상 레진과 이장재간의 결합력에 미치는 영향에 대해 알아보고자 하였다. 의치상 레진에 MMA와 TEGDMA의 농도별 표면 처리와 silane coupling agent로 표면처리 후 이장재를 주입하여 전단결합강도를 측정하였다. MMA와 TEGDMA의 농도별 표면 처리에 따른 의치상 레진과 이장재간의 전단결합강도에서는 Vertex self curing resin에서 95%, 90%, 80%, Kooliner에서는 95%, 90%에서 유의적으로 높게 나타났다(P<0.05). 또한, silane coupling agent 5%로 표면 처리한 그룹이 Vertex self curing resin과 Kooliner 모두에서 전단결합강도가 유의적으로 높게 나타났다(P<0.05). 따라서 적절한 화학적 표면 처리는 의치상 레진과 이장재간의 결합력 증가에 영향을 미치리라 사료된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.769-774
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• 2002

In this study, methyl methacrylate (MMA)- modified polyester polymer concrete, in which the MMA was added to the unsaturated polyester resin, was developed for improving the early-age strength and the workability of the conventional polymer concrete, binder of which was the unsaturated polyester resin. Then the fundamental properties of the polymer concrete such as workability and strength were surveyed. The experimental results showed that the workability was remarkably improved as the MMA contents increased, and the filler-binder ratio was turned out to be important factor for the workability. Slump prediction equation was derived by the regression analysis based on MMA content and filler-binder ratio. Furthermore, early-age strength was greater when the MMA content were increased in the range of 20-40 % but the strength rather showed a tendency of decrease when the MMA content was 50 %.

• Journal of Pharmaceutical Investigation
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• 제18권2호
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• pp.83-88
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• 1988

We examined effects of crosslinking agents, i.e., ethyleneglycol dimethacrylate (EGD) and butanediol dimethacrylate (BDD) containing ester groups on chloromethylation of crosslinked polystyrene resin matrices. It was proved that the ester group in methylmethacrylate (MMA) accelerates the chloromethylation of the divinylbenzene (DVB)-crosslinked styrene-MMA copolymer. As the MMA content increased in the styrene-MMA copolymers, the chloromethylation was enhanced. Complete chloromethylation was obtained at about 25% MMA content.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.379-382
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• 2003

In this study, methyl methacrylate (MMA)- modified unsaturated polyester mortar, in which the MMA was added to the unsaturated polyester resin, was developed for improving the early-age strength and the workability of the conventional polymer concrete, binder of which was the unsaturated polyester resin. Then the strength properties of the MMA-modified unsaturated polyester mortar were surveyed. The experimental results showed that early-age strength was greater when the MMA contents were increased in the range of $20{\sim}40%$, but the strength rather showed a tendency of decrease when the MMA contents was 50%.

• 한국건설순환자원학회논문집
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• 제7권3호
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• pp.224-234
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• 2019

토목구조물의 교면은 토목구조물 상부에 방수층이 존재하고 방수층 상부에 아스콘이나 콘크리트로 포장층을 마무리하여 교면의 시공을 완성하고 있다. 그러나 아스팔트계열은 뛰어난 감온성으로 고온에서 용융되는 취약한 특성을 지녔고, 이는 아스콘 포설시 고온으로 인하여 방수재가 용융되어 두께저하로 인한 하자 발생률이 증가하게 된다. 본 연구에서는 교면에 적용되는 MMA(Methyl Methacrylate)의 경질 Type과 연질 Type에 대하여 동시 사용시 배합에 따른 경화상태를 확인하고 각각의 인장강도와 신장률이 관련 품질기준에 대한 성능 만족 여부와 적정 배합비율을 확인해 보고자 한다. 그 결과 MMA 경질 수지 또는 연질 수지를 단독으로 사용하게 될 경우 경질 수지는 인장특성을 연질 수지는 신장특성이 명확하게 나타나기 때문에 수지의 단독 사용으로는 KS F 4932의 인장성능 품질기준을 만족시키지 못하는 것으로 나타났고, 파우더 양이 총 배합량 중 56.25%를 초과하게 될 경우에는 경화 후 표면에 공극이 발생되고 셀프 레벨링이 불가능하여 불균질한 표면을 형성하는 것으로 확인되었다. 또한, 경질 수지: 연질 수지: 파우더 비율을 15g: 85g: 150g으로 설정한 시험편은 인장강도 $1.5N/mm^2$, 신장률 133%가 나타남에 따라 KS F 4932의 인장성능을 만족하는 것으로 확인되었다.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.423-430
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• 1993

The purpose of this study was to investigate the effect of ferric and ferric ions contained in phosphoric acid solution as a pretreatment solution on bonding of MMA/TBBO resin to dentin. Each of 1 % and 3 % ferric chloride. cupric chloride. cupric sulfate. and cupric nitrate was mixed into 10% phosphoric acid solution and pretreated dentin surface of bovine anterior teeth for 30 seconds followed- by water rinse and dry. Tensile bond strength was determined after bonding of pretreated dentin with MMA/TBBO resin by use of brush-on ;technique and storing for 24 hours in 3it distilled water. The amount of cupric ions adsorbed on pretreated dentin surface was detected by Wave-Dispersion X-ray microanalyzer for different groups of each pretreatment solution containing cupric salts. The pretreatment with cupric ions contained in 10% phosphoric acid solution was effective to increase bonding strength of MMA/TBBO resin to dentin but not in case of ferric ions. The pretreatment with 3 % cupric chloride and cupric nitrate both enhanced significant increase in bonding strength compared to the control group of 10% phosphoric acid solution(p<0.05). Cupric ions measured in pretreated dentin surface was higher in 3 % cupric chloride group than in 1% cupric chloride group, but couldn't find distinct relationship from the results of this experiment between the amount of adsorbed cupric ions according to the kind of cupric salts and the bonding strength value.

• Restorative Dentistry and Endodontics
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• 제34권4호
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• pp.371-376
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• 2009

이 연구에서는 Mineral Trioxide Aggregate (MTA)와 4-methacryloxyethyl trimellitate anhydride (4-META) / methyl methacrylate (MMA) & tri-n-butylborane (TBB) 레진을 혼합하여 치근단 역충전 재료로 사용하였을 때의 미세누출을 MTA, 포틀랜드 시멘트와 비교하였다. 발치된 사람 치아의 근관형성 및 충전 후 치근단 절제와 역충전 와동을 형성하였다. MTA, Portland cement, MTA와 4-META/MMA & TBB레진을 혼합한 각각의 재료로 치근단을 역충전한 후 methylene blue dye에 72시간 동안 침적하여 염료가 침투한 길이를 10배 현미경 하에서 측정하였다. MTA와 4-META/MMA & TBB 레진 혼합 충전 군에서는 포틀랜드 시멘트나 MTA 충전군보다 통계적으로 유의하게 적은 미세 누출을 보였으며, 포틀랜드 시멘트와 MTA 충전군의 미세 누출 정도는 통계적으로 차이가 없었다. 이 실험의 결과로 보아 MTA와 4-META/MMA & TBB레진 혼합 재료는 치근단 역충전시 포틀랜드 시멘트나 MTA에 비해 낮은 초기 미세누출을 보여, 치근단 봉쇄 효과가 우수한 것으로 사료된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.429-432
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• 2003

MMA-modified fiberglass-reinforced plastic composite pipe was produced by using the binder of MMA-modified unsaturated polyester resin in which low viscosity MMA was added to unsaturated polyester resin. Sixteen specimens were made of polymer mortar and fiberglass-reinforced plastic by the centrifugal method. For these specimens the external strength tests were carried out by taking the core thickness consisting of polymer mortar and the fiberglass content per unit area as experimental variables to figure out the effect of variations of these variables influencing on flexural rigidity that is an important property for the composite pipe. Results of this study are believed to provide the basic data for more economical and practical design of MMA-modified fiberglass-reinforced plastic composite pipe.

• The Journal of Advanced Prosthodontics
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• 제14권5호
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• pp.305-314
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• 2022

PURPOSE. The aim of this study was to evaluate the flexural strength of a 3D-printed denture base resin (Cosmos Denture), after different immediate repair techniques with surface treatments and thermocycling. MATERIALS AND METHODS. Rectangular 3D-printed denture base resin (Cosmos Denture) specimens (N = 130) were thermocycled (5,000 cycles, 5℃ and 55℃) before and after the different repair techniques (n = 10 per group) using an autopolymerized acrylic resin (Jet, J) or a hard relining resin (Soft Confort, SC), and different surface treatments: Jet resin monomer for 180 s (MMA), blasting with aluminum oxide (JAT) or erbium: yttrium-aluminum-garnet laser (L). The control group were intact specimens. A three-point flexural strength test was performed, and data (MPa) were analyzed by ANOVA and Games-Howell post hoc test (α = 0.05). Each failure was observed and classified through stereomicroscope images and the surface treatments were viewed by scanning electron microscope (SEM). RESULTS. Control group showed the highest mean of flexural strength, statistically different from the other groups (P < .001), followed by MMA+J group. The groups with L treatment were statistically similar to the MMA groups (P > .05). The JAT+J group was better than the SC and JAT+SC groups (P < .05), but similar to the other groups (P > .05). Adhesive failures were most observed in JAT groups, especially when repaired with SC. The SEM images showed surface changes for all treatments, except JAT alone. CONCLUSION. Denture bases fabricated with 3D-printed resin should be preferably repaired with MMA+J. SC and JAT+SC showed the worst results. Blasting impaired the adhesion of the SC resin.

• 한국도로학회논문집
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• 제14권4호
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• pp.51-61
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• 2012

PURPOSES : This study deals with the working life of polymer concrete, which is typically used as a repair or overlay material for portland cement concrete pavements. METHODS : In the scope of this study, laboratory testing was conducted on fresh MMA modified UP polymer concrete, which uses an MMA monomer for viscosity adjustment and strength improvement of UP resin. The experimental variables were temperature (-20 to $+20^{\circ}C$) and binder components (MMA, MEKPO, and DMA). RESULTS : The result showed that the optimum binder ratios for polymer concrete production were 12, 11, and 10 wt.% when the MMA contents were 20, 30, and 40 wt.%, respectively. The working life of polymer concrete depending on temperature and binder components could be expressed by a logarithmic functional formula. The coefficient of variation for each binder component was the highest for DMA content while the lowest for MEKPO content. Also, the contents of each binder component for ensuring the working life of 60 minutes were proposed. CONCLUSIONS : Ultimately, the present study derived a linear regression equation estimating 60 minutes working life based on the setting times of each binder component.