• 대한두개안면성형외과학회지
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• 제13권2호
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• pp.125-129
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• 2012

Purpose: Methylmethacrylate is the most commonly used alloplastic material in cranioplasty. However during the polymerization of methylmethacrylate, a significant exothermic reaction takes place. This reaction may result in thermal injury to the brain tissue and other soft tissues. Also it is difficult to make three-dimensional methylmethacrylate implant that is perfectly matched to the defect during the operation time. We report on the molding technique of methylmethacrylate implant using plaster mold and the rapid prototyping model in cranioplasty. Methods: A 44-year-old male was referred to the department for severe frontal hollowness. He was involved in an automobile accident resulting in large frontal bone defect with irregular margin. The preformed patient-specific methylmethacrylate implant was made using plaster mold and the rapid prototyping model before the operative day. The methylmethacrylate implant was placed in the frontal defect and rigidly fixed with miniplates and screws on the operative day. Results: The operation was performed in an hour. In the 6 months follow-up period, there were no complications. Patient was satisfied with the results of cranioplasty. Conclusion: Safe cranioplasty was performed with the preformed patient-specific methylmethacrylate implant using plaster mold and the rapid prototyping model. The result of this method was satisfactory, aesthetically and functionally.

• 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.

• Elastomers and Composites
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• 제28권3호
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• pp.183-190
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• 1993

The radical copolymerization with propagation and depropagation is presented in order to estimate reactivity rate of monomers and $K_{11}$(the equilibrium constant for propagation and depropagation) in the copolymerization of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-acrylonitrile$. The value of ${\alpha}-methylstyrene$ and methylmethacrylate and $K_{11}$ are found to be 0.48, 0.47 and 5.0 respectively. The value of ${\alpha}-methylstyrene$ and acrylonitrile and the $K_{11}$ are found to be 0.1251, 0.0577 and 23.8 respectively. The treatment rate constant of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-co-acrylonitrile$ in the copolymerization is estimated to be 2.5, 80.72 regardless of monomer feed composition.

• 대한화학회지
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• 제21권4호
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• pp.246-255
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• 1977

여러 종류의 層間 陽이온을 가지고 있는 層狀 硅酸鹽上에서 일어난 methylmethacrylate의 吸着에 關하여 赤外線 分光法과 X-ray로 硏究하였다. 吸着된 methylmethacrylate의 여러 개의 特性 carbonyl band가 陽이온의 種과 脫水溫度에 따라서 다르게 1723∼1547$cm^{-1}$의 範圍에서 나타났다. 190$cm^{-1}$程度로 shift한 carbonyl 伸縮 band는 polyvalent 陽이온에만 나타났으며 $>C=O{\cdot}{\cdot}{\cdot}M^{n+}$型 着物形成 基因하는 것이었다. 1703∼1640$cm^{-1}$에서 나타난 band는 carbonyl 酸素와 陽이온 水 또는 陽이온 水酸基와의 水素結合에 依한 것이었고 shift한 정도는 層間 陽이온의 polarizing power와 좋은 相互 關係를 이루었다. 그러나 1723$cm^{-1}$에서 나타난 band는 陽이온의 鍾과는 相互 關係가 없었으며 carbonyl ,酸素와 表面 水酸基와의 相互 作用으로 因한 것이었다. Interlamellar spacing을 계산해 본 結果 methylmethacrylate의 分子平面은 硅酸鹽의 層과 平行하게 놓여 있는 것 같다.

• 대한치과의사협회지
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• 제25권10호통권221호
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• pp.953-962
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• 1987

• The Journal of Advanced Prosthodontics
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• 제12권5호
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• pp.322-328
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• 2020

PURPOSE. This study evaluated the shear bond strength between 3D printed provisional resin and conventional provisional resin depending on type of conventional provisional resin and different surface treatments of 3D printed resin. MATERIALS AND METHODS. Ninety-six disc-shaped specimens (Ø14 mm × 20 mm thickness) were printed with resin for 3D printing (Nextdent C&B, Vertex-Dental B. V., Soesterberg, Netherlands). After post-processing, the specimens were randomly divided into 8 groups (n=12) according to two types of conventional repair resin (methylmethacrylate and bis-acryl composite) and four different surface treatments: no additional treatment, air abrasion, soaking in methylmethacrylate (MMA) monomer, and soaking in MMA monomer after air abrasion. After surface treatment, each repair resin was bonded in cylindrical shape using a silicone mold. Specimens were stored in 37℃ distilled water for 24 hours. The shear bond strength was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were analyzed by scanning electron microscope. Statistical analysis was done using one-way ANOVA test and Kruskal-Wallis test (α=.05). RESULTS. The group repaired with bis-acryl composite without additional surface treatment showed the highest mean shear bond strength. It was significantly higher than all four groups repaired with methylmethacrylate (P<.05). Additional surface treatments, neither mechanical nor chemical, increased the shear bond strength within methylmethacrylate groups and bis-acryl composite groups (P>.05). Failure mode analysis showed that cohesive failure was most frequent in both methylmethacrylate and bis-acryl composite groups. CONCLUSION. Our results suggest that when repairing 3D printed provisional restoration with conventional provisional resin, repair with bis-acryl composite without additional surface treatment is recommended.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.87-92
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• 2002

At present, the polymer-modified mortars are used as high-performance as well as multi-functional materials in the construction industry. The purpose of this study is to synthesize polymer to modify in cement mortars and make test samples to understand pore size distribution. This paper deals with the effect of monomer ratio on the typical properties of polymer-modified mortars using Methylmethacrylate-Butyl Acrylate(MMA/BA) latexes synthesized through emulsion polymerization. From the results, we knew that the pore volume of polymer-modified mortars using Methylmethacrylate-Butyl Acrylate latexes at bound MMA contents of 70 and 60 percent is 7.5-75cm$^3$/g and the fine pore volume is increased with an increase in the polymer-cement ratio. The total pore volume of polymer-modified mortars using MMA/BA latexes is linearly reduced with an increase in the bound MMA content and increased in the polymer-cement ratio.

• 폴리머
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• 제26권2호
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• pp.245-252
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• 2002

상용화제로 poly(styrene-b-methylmethacrylate) [U(S-b-MMA)] 블록 공중합체를 포함한 polymethylmethacrylate (PMMA)와 polyvinylmethylether (PVME) 블렌드의 열역학적 특성과 이들의 기체 투과특성을 조사하였다. 블렌드에 포함된 여러 고분자들 간의 상호작용 에너지를 상분리 온도와 상태방정식 이론으로부터 구하기 위해 다양한 조성의 poly(styrene-co-methylmetha-crylate) (SMMA) 랜덤 공중합체를 제조하고 이를 PVME와 블렌드하여 단상의 블렌드를 제조하였다. 공중합체 내의 스티렌 함량이 70 wt% 이상에서는 SMMA/PVME 블렌드는 단상을 형성할 뿐아니라 LCST 거동을 나타내었다. 여기서 구한 상호작용 에너지를 기초로 PMMA/PVME 블렌드의 상용성을 향상시키기 위해 P(S-b-MMA) 블록 공중합체를 상용화제로 첨가하였다. 분산상으로 존재하는 PVME 고무 입자들의 평균 크기는 상용화제 첨가량이 5 phr 이하에서는 점차 감소하지만 더 이상의 상용화제를 첨가해도 분산상의 크기 변화는 관찰되지 않았다. 일정 블렌드 조성에서 기체 투과도도 상용화제의 양이 5 phr 일때까지는 증가하지만 그 이상의 상용화제 함량에서는 기체 투과도 변화가 관찰되지 않았다.

• 대한화장품학회지
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• 제32권1호
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• pp.35-44
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• 2006

최근에 고분자, 지질 또는 그 밖의 여러 소재를 이용한 캡슐화 연구는 다양한 기능성 성분의 안정화 및 방출 제어를 목적으로 진행된 바 있다. 본 연구는 주요한 기능성 성분들을 캡슐화할 수 있는 또 하나의 새로운 방법으로써, methylmethacrylate (MMA)와 trimethoxysilylpropylmethacrylate (TMPMA)로 구성된 MMA-TMPMA 공중합체를 제조하였다. Poly(MMA-co-TMPMA)로 제조된 구는 속이 빈 형태의 미립구이며 레티놀, 레티닐팔미테이트, 토코페릴아세테이트, 아스코빌테트라이소팔미테이트와 같은 비타민유도체나 유용성감초추출물과 같은 기능성 성분들을 core 성분으로 캡슐화하는데 매우 유용하였다. 제조된 poly(MMA-co-TMPMA) core-shell 형태의 미립구 평균 입도는 $0.1{\sim}10{\mu}m$, 기능성 성분의 로딩 함량은 $15{\sim}25%$이며 로딩 수율은 90% 이상이었다. Poly(MMA-co-TMPMA) core-shell 형태의 미립구에 함유된 기능성 성분의 안정화는 캡슐 자체에 의한 안정화 외에 미립구 표면에 자외선차단 silane 전구체를 도입함으로써 향상시킬 수 있었다. 기능성 성분에 대한 광안정성은 자외선차단 전구체가 함유된 poly(MMA-co-TMPMA) 미립구의 경우, 자외선차단 전구체가 도입되지 않은 미립구에 비해 25%정도 더 항상됨을 확인할 수 있었다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.311-311
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• 2006

The morphology of Poly(styrene-b-methylmethacrylate) (P(S-b-MMA)) block copolymer thin films deposited on silicon wafers was controlled by treating the substrates with Self-Assembled Monolayers (SAM) of phenylsilanes with different alkyl chain lengths. It was found that the treatment with SAM strongly modified the substrates properties, especillay the surface energy, as compared with bare silicon oxide. By futher adjusting the molecular weight of P(S-b-MMA), a variety of morphologies could be generated, including a perpendicular orientation of lamellea of PS and PMMA, which is required for industrial applications.