• 한국응용과학기술학회지
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• 제27권4호
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• pp.461-469
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• 2010

Polyurethane adhesive is used in various fields as flexible packaging materials including a food packaging field. Therefore, the purpose of this study is synthesis of polyurethane adhesive which uses aliphatic isocyanate, and compares with aromatic isocyanate. The isocyanates for this test are toluene-2,4-diisocyanate(TDI), hexamethylene diisocyanate(HDI), 4,4-dicyclohexyl ethane diisocyanate($H_{12}MDI$), and isophorone diisocyanate(IPDI). And, the effect of any other diisocyanate are evaluated by several methods as for curing rate test, accelerate weathering test, and peel strength test. The polyurethane adhesive using curing catalyst and HDI has adhesion strength of about 560 g/15 mm between aluminium foil and nylon, about 1,520 g/15 mm between nylon and CPP. Those parameters are similar to polyurethane adhesive with TDI. Also, in case of curing rate, those are similar to TDI type polyurethane adhesive. Moreover, data of ${\Delta}E$ as color variation by QUV tester is equal to 4.12, as 48% against those of TDI type.

• 한국응용과학기술학회지
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• 제30권3호
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• pp.551-559
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• 2013

To investigate the adhesion effect of sodium bisulfite content in making blocked isocyanate, wood adhesive PB-1, PB-2, PB-3 and PB-4 containing sodium bisulfite content of 15%, 22.5%, 30% and 37.5% were synthesized respectively. As a result, when the amount of sodium bisulfite increased in adhesives, the tensile strength was found to be proportionally increased. The final adhesive mixtures were manufactured using a two-components system which are prepared by mixing two separate protein and BI solutions due to the precipitate in the adhesives. As PVA was added to adhesives to increase tenacity, the plywood dehiscence phenomenon after cold pressing process was declined. By addition of PVA, the tensile strength was improved up to $6.5{\sim}7kgf/cm^2$ with BI/protein ratio from 1:6 up to 1:8. Phase separation between milk fat and aqueous layer was disappeared after addition of emulsifier, Tween 20. Additon of Tween 20 showed tensile strength up to $5{\sim}6.5 kgf/cm^2$ at NCO/protein ratio of 1:12 ~ 1:14 without phase separation.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.755-764
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• 2020

Due to pronounced mechanical performance and being environmental friendly, aqueous polymer isocyanate adhesive (API) has been widely applied in the production of formaldehyde-free wood products. In this study, flame retardant formaldehyde-free plywood was prepared by incorporation of flame retardants into the API adhesive. Partially phosphorylated poly (vinyl alcohol) (PPVA) which was prepared by reacting poly (vinyl alcohol) with phosphoric acid was used to replace PVA in API formula. In addition, Mg-Al layered double hydroxides (LDH) was chosen as additive flame retardant, replacing traditional filler CaCO₃ in API adhesive formula. And then, the flame retardant API adhesive with main agent (PPVA replacing PVA70wt.%, SBR emulsion 30wt.%), curing agent 10wt.% (accounts for of the main agent), and 20wt.% LDHs (accounts of the main agent) was used to prepare flame retardant plywood. The effect of application of PPVA and Mg-Al LDH on bonding strength of plywood was investigated. The flammability characteristics of the plywood were determined by cone calorimeter test (CCT). The results revealed that compared with the plywood prepared with API adhesive, the use of PPVA and LDH enhanced the flame retardancy of plywood without negatively affecting bonding strength. The CCT tests indicated that the heat release and smoke production flame retardant API plywood were lower than those of the ordinary API glued plywood. Promising developments for flame retardant API adhesive were expected in future applications of flame retardant formaldehyde-free plywood.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.907-916
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• 2020

This research was conducted to investigate the linear expansion and resistance properties of a composite board (com-ply). This board was made of medium-density fiberboard (MDF) laminated using avocado (Persea americana), mahogany (Swietenia mahogani), and pine (Pinus merkusii) veneers. These three types of veneers were laminated on both surfaces of the MDF using adhesives, namely, epoxy and isocyanate. Glue (250 g·m^-2) was spread on the surface, followed by cold press for 3 h with an applied pressure of 15 kg·cm^-2. The research result revealed that com-ply exhibited an increased dimensional stability compared with MDF, indicated by reduction in water absorption, thickness swelling, and linear expansion. The com-ply made of the pine veneer and isocyanate adhesive exhibited high density, water absorption, thickness swelling, and screw withdrawal load. The com-ply that exhibited the strongest resistance to drywood termite attacks was the one made of the mahogany veneer and isocyanate adhesive. Moreover, the com-ply that exhibited the biggest weight loss (3.6 %) was made of the pine veneer and epoxy adhesive. The results of this research may facilitate in manufacturing com-ply using the selected veneer and adhesive without the application of hot press.

• 폴리머
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• 제36권2호
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• pp.119-123
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• 2012

금속 박막 접착제로 사용되는 용제형 폴리우레탄 접착제의 라미네이팅 조건에 따른 접착 메커니즘과 이에 따른 접착력 변화를 살펴보았다. 강판에 도포된 접착제의 열처리 온도와 시간에 따라 폴리우레탄 접착제의 blocking agent로 사용된 옥심이 분해되어 이소시아네이트기가 발현되고 이들이 강판과 알루미늄 포일의 하이드록실기와 반응하여 강판 접착이 이루어짐을 알 수 있었다. 접착 강도는 접착 온도 및 시간에 따라 발생된 이소시아네이트 함량과 밀접한 관계가 있음을 확인하였다. 하지만 지나친 접착 온도 및 접착 시간의 증가는 접착제에 함유된 용매의 감소와 접착제 분해를 유발시켜 접착 강도를 감소시킴을 알 수 있었다.

• 접착 및 계면
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• 제17권2호
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• pp.56-61
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• 2016

본 연구에서는 아크릴 접착제의 물성에 대한 주 모노머의 영향을 비교하기 위하여 2-ethylhexyl acrylate 대신에 butyl acrylate를 사용하여 acrylic acid와 2-hydroxyethyl methacrylate의 공중합체를 합성하고 2종의 경화제를 이용하여 접착 물성을 연구하였다. 선형의 측쇄사슬을 가진 butyl acrylate계 점착제는 가지형태의 측쇄를 가진 2-ethylhexyl acrylate계 접착제에 비해 낮은 접착특성을 보였다. 경화제의 경우 가교점이 많고 가교반응을 통해 유연한 ether나 ester그룹을 생성하는 epoxy형 경화제에서 우수한 물성을 보였고 관능기인 산의 농도가 높을수록 접착특성이 향상되는 것을 관찰하였다.

• 폴리머
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• 제37권2호
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• pp.232-239
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• 2013

A series of novel imidazole-blocked diisocyanate bioadhesives (IBAs) were synthesized from reaction of toluene 2, 4-diisocyanate (TDI), isophorone diisocyanate (IPDI), hydroxyl-terminated polylactide (HO-PLA-OH), 1,1,1-trimethylolpropane (TMP), and imidazole. Synthesis of IBAs was confirmed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) revealed that the TDI-based IBA had lower thermal dissociation temperature and a faster deblocking rate than IBA based on IPDI. Hydroxyl-terminated polyurethane (HPU) was introduced to study the adhesive effect of the synthesized IBAs. Improvement on elastic modulus, tensile strength and water resistance of IBA-modified HPU in comparison with neat HPU suggested the good adhesive effect of IBA due to the strong chemical reaction between released NCO groups from IBA and hydroxyl groups from HPU.

• Elastomers and Composites
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• 제36권4호
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• pp.225-236
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• 2001

2원, 3원 공중합 점착제의 물성을 향상시키기 위해 4인 공중합체를 단량체의 종류와 농도, 개시제의 종류와 농도, 반응온도와 반응시간, 용매의 종류 및 단량체와 용매의 혼합비를 변화시켜 합성하여 점착제의 물성인 점도, 분자량, 전환율, 고형분과 구조분석들을 고찰하였다. 합성한 각 중합체에 내하여 가교제의 종류 및 농도를 변화시켜 점착세의 성능인 점착력. 유지력, 내열성, 내후성, 경시변화를 고찰한 결과, 디음과 같은 결론을 얻었다. 4원 공중합체의 최적 혼합비는 BA/2-EHA/MMA/2-HEMA인 경우, 주단량체인 BA/2-EHA가 80%, 공단량체인 MMA가 15%, 관능성 단량체 2-HEMA가 5%. BA/2-EHA/MMA/AA인 경우, 주단량체인 BA, 2-EHA가 80%, 공단량체인 MMA기 15%, 관능성 단량체 AA가 5%이다. 4원으로 합성한 RA/2-EHA/MMA/2-HEMA의 점착제에 가교제로 이소시아네이트가 적합하였으며, BA/2-EHA/MMA/AA인 경우는 가교제로 멜라민계가 적합하고 점착력의 경시변화는 가교제로 이소시아네이트(PTDI)나 멜라민계 모두 균일하있으며, 내후성 시험후에 표면관찰을 하면 멜라민계는 점착제 잔유물이 남아있어 불안정했고, PTDI는 점착제 잔유물이 전혀 없이 안정성이 우수하였다.

• Journal of the Korean Wood Science and Technology
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• 제46권2호
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• pp.143-148
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• 2018

The aim of this research was to determine the physical and mechanical properties of glued laminated lumber (glulam) made from jabon (Anthocephalus cadamba) and pine (Pinus merkusii). Three layers of lamina from each wood species were bonded using isocyanate adhesive with a glue spread of $280g{\cdot}m^{-2}$ and then pressed using cold press with a specific pressure of 1.47 MPa. Samples had dimensions of $3cm{\times}6cm{\times}100cm$ (thickness, width, and length, respectively). Glulam properties were tested based on Japanese Agricultural Standard (JAS) 234-2003. The results showed that the density of glulam was $0.36g{\cdot}m^{-3}$ for jabon and $0.73g{\cdot}m^{-3}$ for pine. The moisture content of all glulams fulfilled the JAS standard. The mechanical properties of pine glulam fulfilled the JAS standard in all tests, whereas jabon glulam fulfilled the standard in the modulus of rupture and shear tests.

• 접착 및 계면
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• 제15권3호
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• pp.109-115
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• 2014

본 연구에서는 내부에 이소시아네이트를 포함하는 microcapsule을 합성하였으며, 제조된 microcapsule에 대한 분석 및 폴리우레탄 수지와 병용했을 때의 기계적 물성과 접착특성에 대해서 고찰하였다. 전자현미경을 사용해서 합성된 microcapsule이 구형의 외관을 갖는 것을 확인하였으며, FT-IR과 TGA 분석을 통해서 microcapsule의 core 물질이 IPDI인 것과 각 구성요소들의 성분비를 확인하였다. 폴리우레탄 수지 자체 및 microcapsule을 포함한 경우의 접착력 및 물성을 평가한 결과 접착수지 내에 포함된 microcapsule 내 IPDI의 가교반응에 의해서 폴리우레탄 수지 자체에 비해 접착력, 인장강도, 내마모 특성이 크게 향상되는 것을 확인하였다.