• 공업화학
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• 제4권4호
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• pp.823-829
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• 1993

Linseed oil fatty acid(LOFA), phthalic anhydride(PAA) 및 trimellitic anhydride(TMA), trimethylol propane(TMP)을 사용하여 기본적인 유장(oil length) 50%의 중유성 알키드를 합성하고 trimethylol propane triacrylate (TMPTA)를 그라프트 공중합시켜 수용성 TMPTA 변성 알키드수지를 제조하였다. 알키드수지의 산가는 TMA함량으로 제어하였으며, 수용화에는 N,N-Dimethylethanol amino(DMEA)를 중화제로 사용하였다. TMA함량에 따른 산가별 내수성 및 수용화의 최적조건을 산출한 후, TMPTA의 첨가량 변화에 의한 분자량, 유리전이온도, 수용화 후의 점성도, 그라프트율을 측정하였으며, 멜라민 수지를 사용하여 가교시킨 막의 경화온도별 겔분율변화를 조사하였다. TMA첨가량 5.3~7.0%, 산가 40~50의 범위에서 알키드 수지의 내수성과 수용화가 가장 좋은 균형을 나타냈으며, 변성 알키드수지의 경우 TMPTA의 양이 증가할수록 분자량, 수용액의 점성도, 겔분율은 증가하였으나, 유리전이온도(Tg)는 감소하였다. 고형분 함량에 따른 점성도 변화는 고형분 40%일 때보다 50%일 때가 점성도가 낮게 나타났으며 중화도에 따른 수용액의 점성도 변화는 중화도가 높을수록 점성도는 낮아지나 중화도 100~110 사이에서는 거의 변화가 없음을 알 수 있었다. TMPTA의 그라프트율은 TMPTA의 첨가량이 4wt%인 때가 가장 높게 나타남이 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.

• 폴리머
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• 제39권1호
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• pp.122-129
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• 2015

최근 해양 산업에서는 해양환경에 잔류성은 없으면서 방오성능은 우수한 새로운 종류의 방오도료 수지 개발이 해결해야 할 시급한 과제로 대두되고 있다. 본 연구에서는 폴리우레탄계 수지를 방오도료용 수지로 적용하여 평가하였다. Polyethylene glycol(PEG), 4,4'-diphenylmethane diisocyanate(MDI) 2,2'-bis(hydroxyl methyl)propionic acid(DMPA)를 사용하여 중합한 후 방오성능을 발휘하는 치환기로서 quaternary ammonium salt를 치환시켰다. 합성된 수지는 최종적으로 필름화하여 해수 내에서의 마모특성을 확인하였다. 그 결과, PEG의 분자량이 600인 방오도료용 폴리우레탄 수지의 기계적 물성이 가장 양호함을 알 수 있었으며, quaternary ammonium salt의 함량이 일정 이상으로 많은 경우에는 수지에 대한 부착력이 저하됨을 확인하였다.

• Korean Chemical Engineering Research
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• 제44권1호
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• pp.35-39
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• 2006

본 실험에서는 모델 시스템으로써 PVP 수지에서 과당, 포도당과 같은 당 시료와 젖산, 아세트산과 같은 유기산을 사용하여 온도 변화에 따른 체류 시간의 변화 정도를 알아보았다. 펄스 시험을 사용하여 당 시료의 온도 변화에 따른 체류 시간 변화를 알아본 결과, 그 변화가 크지 않았다. PVP 수지는 일반적으로 당 분리에 사용되는 분리 수지가 아닌 사실에서 예측할 수 있듯이 현저히 떨어지는 분리능을 보였고, 온도 변화에 따른 분리능의 변화 또한 나타나지 않았다. 반면에, PVP 수지에서 유기산의 경우에는 상당한 변화를 보였다. 따라서, 유기산에 대한 정량적 흡착특성의 변화를 알아보기 위하여 $35^{\circ}C$, $65^{\circ}C$ 온도에서 전단 분석하여 그 차이를 확인하였다. 이러한 온도에 대한 흡착특성은 SMB(simulated moving bed)와 같은 대규모 크로마토그래피 공정에 이용될 수 있을 것으로 판단한다.

• 대한치과보철학회지
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• 제45권2호
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• pp.159-168
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• 2007

Statement of problem: Literature showed different results on the durability of bonded ceramic restoration. Purpose: The purpose of this article is to review the effect of surface treatment of ceramics in resin-ceramic bond to get predictable results. Material and method: PubMed data base was utilized to search the articles which were written in English and published in 1986 and 2006. Some electronic published articles which are forthcoming to publish in paper were also included for this review. This review article focused on the effect of acid etching and silane application on the silica based ceramics. The durability of resin-ceramic bonding, the methodology for bond strength test and resin bonding to alumina or zirconia based ceramics were compared in brief at the end of the review. Results and Conclusion: the effect of silane application can be influenced by the contaminations of saliva or solutions. Micromechanical retention by acid etching as well as silane application plays an important role in initial and durable bond strength between resin and ceramic. The use of phosphate modified resin cement following tribochemical silica coating and silane application produced best bond strength for alumina or zirconia based ceramics.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4109-4116
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• 2012

An efficient solid-phase methodology has been developed for the synthesis of 2-amino and 2-amidobenzo[d]-oxazole derivatives. The key step in this procedure involves the preparation of polymer-bound 2-aminobenzo-[d]oxazole resins 4 by cyclization reaction of 2-hydroxy-phenylthiourea resin 3. The resin-bound 2-hydroxyphenylthiourea 3 is produced by the addition of 2-aminophenol to the isothiocyanate-terminated resin 2 and serve as a key intermediate for the linker resin. This core skeleton 2-aminobenzo[d]oxazole resin 4 undergoes functionalization reaction with various electrophiles, such as alkylhalides and acid chlorides to generate 2-amino and 2-amidobenzo[d]oxazole resins 5 and 6 respectively. Finally, 2-amino and 2-amidobenzo[d]oxazole derivatives 7 and 8 are then generated in good yields and purities by cleavage of the respective resins 5 and 6 under trifluoroacetic acid (TFA) in dichloromethane ($CH_2Cl_2$).

• 대한치과보철학회지
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• 제46권5호
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• pp.535-543
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• 2008

최근의 레진 접착시스템은 단계를 줄이고 적용과정을 간편화시키는데 주력하고 있으며, 치면에 bonding 및 conditioning 과정 없이 바로 적용 가능한, one-step의 새로운 자가 접착 레진시멘트 (self-adhesive resin luting cement)들이 소개되어 임상에 사용되고 있다. 이에 본 연구의 목적은 자가 접착 레진시멘트와 기존의 레진시멘트의 상아질에 대한 전단 결합 강도를 비교해보고, 자가 접착 레진시멘트 적용시 치면의 식각 처리 여부가 전단 결합 강도에 미치는 영향에 관하여 알아보고자 하는 것이다. 본 연구를 위해 최근 6개월 내 발치된 비교적 건전한 성인의 대구치 45개를 아크릴릭 레진으로 매몰한 다음, 800 grit SiC연마지로 연마를 시행하여 상아질을 노출시켰다. 15개의 치아를 한 군으로 하여, 세 가지 실험군으로 분류하였다. Group 1) 치면에 아무런 전처리 없이 RelyX Unicem 접착. Group 2) 치면에 인산 산부식 처리 후, RelyX Unicem 접착, Group 3) 치면에 Syntac primet + Syntac adhesive + Heliobond 처리 후 Variolink II 접착. 전처리가 완료된 치아 시편 위에 플라스틱 튜브 (직경 3 mm, 높이 3 mm)를 고정한 다음, 제조사의 지시에 따라 각 레진 시멘트를 혼합하여 링 안을 채우고, 광중합을 시행하였다. 접착이 완료된 시편은 $37^{\circ}C$ 항온수조 (증류수)에서 24시간 동안 보관 후, 만능 시험기를 이용하여 1mm/min의 cross head speed로 결합강도를 측정하였으며, 확대경 하에서 파절 양상을 분류 관찰하고, 주사전자현미경을 이용하여 미세구조를 관찰하였다. 측정결과는 SPSS WIN 12.0 프로그램을 사용하여 분석하였으며 다음과 같은 결과를 얻었다. 1. RelyX Unicem의 상아질에 대한 전단결합강도는 Variolink II와 유의한 차이를 보이지 않았다. 2. 상아질에 대한 인산 산부식 처리는 RelyX Unicem과의 전단결합강도를 낮게 하였다. 3. RelyX Unicem과 Variolink II에서는 혼합 파절의 비율이 컸으며, 전단결합강도가 낮았던 인산 산부식 처리 후 RelyX Unicem을 접착한 경우에서는 전체 시편에서 접착성 파절이 관찰되었다. 결론으로 말하면, 자가 접착 레진시멘트와 기존의 레진시멘트의 상아질에 대한 전단결합강도는 유의한 차이를 보이지 않으며, 인산 산부식 처리는 상아질에 대한 자가 접착 레진시멘트의 전단결합강도를 감소시킨다.

• 대한치과보철학회지
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• 제45권4호
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• pp.407-418
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• 2007

Purpose: The objective of this study was to evaluate the effects of hydrofluoric acid concentration & etching time on the shear bond strength between IPS Empress 2 ceramic and resin cement. Material and methods: Thirty three rectangular shape ceramic specimens($20{\times}12{\times}5mm$ size, IPS Empress 2 core materials) were used for this study. The ceramic specimens divided into ten experimental groups with three specimens in each group and were etched with hydrofluoric acid(4%, 9%) according to different etching times(30s, 60s, 90s, 120s, 180s). Etched surfaces of ceramic specimens were bonded with resin cement(Rely X Unicorn) using acrylic glass tube. All cemented specimens were tested under shear loading until fracture on universal testing machine at a crosshead speed of 0.5mm/min and the maximum load at fracture(kg) was recorded. Collected shear bond strength data were analyzed with one way ANOVA and Duncan tests. All etched ceramic surfaces were examined morphologically using SEM(scanning electron microscopy). Results: Shear bond strength of etching group$(35.89{\sim}68.01MPa)$ had four to seven times greater than no-etching group$(9.53{\pm}2.29MPa)$. The ceramic specimen etched with 4% hydrofluoric acid for 60s showed the maximum shear bond strength$(68.01{\pm}11.78MPa)$. Ceramic surface etched with 4% hydrofluoric acid for 60s showed most retentive surface texture. Conclusion: It is considered that 60s etching with 4% hydrofluoric acid is optimal etching methods for IPS Empress 2 ceramic bonding.

• 대한치과교정학회지
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• 제20권3호
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• pp.583-591
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• 1990

If the bond strength is sufficient to resist orthodontic force, orthodontic brackets can be bonded to restorations. Orthodontic brackets were bonded to composite resin and glass ionomer cement restorations with no-mix adhesive or glass ionomer cement. The shear bond strength of adhesives bonded to restorations was studied in vitro. Orthodontic brackets were bonded to 10 extracted natural teeth, 40 composite resin restorations and 40 glass ionomer restorations. The surfaces of composite resin restorations were roughened or applied with bonding agent (Scothbond) after surface roughening. The surfaces of glass ionomer cement restorations were conditioned with acid etching or applied with Scotchbond to etched surface. The adhesive was no-mix resin or glass ionomer cement. The shear bond strength was measured. The results were as follows: 1. Orthodontic brackets could be bonded to composite resin restorations effectively as they could be bonded to acid etched enamel with no-mix adhesive. The shear bond strength was sufficient to resist orthodontic force and was not affected by bonding agent greatly. 2. The shear bond strength of no-mix adhesive bonded to acid etched glass ionomer cement restorations was sufficient to resist orthodontic force. However. the fracture risk of glass ionomer cement restorations was increased during debonding. The bonding agent couldn't increase the shear bond strength greatly. 3. The shear bond strength of glass ionomer cement bonded to glass ionomer cement restorations was lower than that of no-mix adhesive. The shear bond strength was sufficient to resist orthodontic force and was greatly decreased by bonding agent. 4. The shear bond strength of glass ionomer cement bonded to composite resin restorations was too low to resist orthodontic force.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.447-459
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• 1994

The purpose of this study is to evaluate of shear bond strength of light-curing composite resin to light-curing glass ionomer cement. Composite resin and glass ionomer cement have been widely used as an esthetic filling materials in dental clinics. To achieve better clinical results, sandwich technic was developed with conpensating for disadvantages of these two materials. Especially, light-curing glass ionomer cement provided greately improved bonding strength of teeth or composite resin, and then excellent clinical results can be acquired. In this study, 6 commercial light-curing glass ionomer cements(3 commercial restorative materials : Fuji II LC, Variglass VLC, Vitremer, and 3 commercial lining materials : Fuji Lining LC, Baseline VLC, Vitrebond) were devided two groups. According to manufacturer's appointment, no surface treatment was referred to N groups. Supposing. of clinical practice, surface grinding with water spray at 320 grit sand paper, 40 seconds etching with 37% phosphoric acid, 20 seconds washing, 20 seconds air drying was referred to N groups. Totally 12 experimental groups were devided, and all 120 specimens from 10 specimens of each groups were made. After light-curing composite resin was bonded to light-curing glass ionomer cement, shear bond strength was tested by Instron universal testing machine between glass ionomer cement and composit resin. The data were analyzed statistically by Student's t-test and ANOVA. The obtained results were as follows; 1. In light-curing glass ionomer cement, restorative materials showed higher shear bond strength to composite resin than lining materials(p<0.05). 2. Variglass VLC of restorative material group and Baseline VLC of lining material group have highest shear bond strength to composite resin(p<0.001). 3. In light-curing glass ionomer cement, surface grinding and acid etching reduced shear bond strength to composite resin(p<0.001)}. 4. VGN group 1s highest shear bond strength to composite resin, VBE group is lowest shear bond strength to composite resin(p<0.001).