• Journal of the Korean Wood Science and Technology
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• 제8권2호
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• pp.1-5
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• 1980

This study is carried out to determine the scavenging effect of resorcinol added into the urea formaldehyde resin on the formaldehyde release of plywood, as the preliminary study of using the phenolic substances. The method for formaldehyde determination used in this report is the improved chromotropic acid determination. The results are summarized as follows: 1. Resorcinol added into the urea formaldehyde adhesive acts as a good scavenger. 4 percent of resorcinol reduced the formaldehyde release to less than half content. 2. Adding resorcinol gave better glue shear strength than that of control, showing the peak of the shear strength, at 2 percent and decreased to the same strength as control along its content of 4 percent. 3. Moisture content of air dried plywood met the standard very well.

• Elastomers and Composites
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• 제28권4호
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• pp.274-282
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• 1993

Resorcinol-tannin-formaldehyde-latex(RTFL) adhesive was prepared to bond SBR to nylon in reinforced rubber composites. A key factor of adhesive contributes to the adhesion strength between SBR and nylon was the toughness of adhesive itself. Although the stiffness and strength of adhesive film decreased slightly with increasing level of tannin substitution for resorcinol in a standard RFL adhesive, the maximum toughness of adhesive film, which showed yield behavior and high dissipative capacity, was obtain by 60% tannin substitution. However, a marked softening and reduction in toughness occurred at sufficiently high substitution. Also, the adhesive film, which was heat-treated to simulate cure, showed higher strength than the unheated film. Thus, the properties of tannin containing adhesives could be optimized by using 40/60 weight ratio of the resorcinol/tannin in RTFL adhesive composition as well as heat treatment of adhesive film.

• Journal of the Korean Wood Science and Technology
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• 제42권1호
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• pp.34-40
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• 2014

흰개미 방제 및 방곰팡이 효력이 입증된 저독성 네오티코치드계 목재보존제가 집성재 제조용 레조르시놀계 접착제의 접착력에 미치는 영향을 조사하였다. ACQ, CUAZ, 네오니코치드계 약제를 도포 처리한 다음 건조시킨 소나무 판재를 사용하였으며, 집성 접착 후에 블록 전단시험편을 채취하여 상태 및 촉진 열화 시험 후의 전단접착력과 목파율을 측정하여 비교하였다. ACQ 및 CUAZ 처리 집성재는 무처리 및 네오니코치드계 목재보존제 처리 집성재에 비하여 낮은 전단접착력을 보여 접착력 저하가 인정되었다. 이것은 이들 방부제 중에 함유되어 있는 구리화합물에 기인하는 것으로 판단되었다. 네오니코치드계 목재보존제 처리 집성재는 상태 및 촉진열화 시험 후에도 가장 우수한 전단접착력을 나타내 레조르시놀계 접착제의 접착성능에는 영향을 미치지 않는 것으로 판단하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.25-26
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• 2022

In this study, glued laminated timber were manufactured by different types of adhesives for larch and spruce. Adhesives used to manufacture glued laminated timber include resorcinol resin, phenol resorcinol resin, melamine resin, and polyurethane. The char thickness and char rate according to the type of adhesive forglued laminated timber were analyzed. Melamine, resorcinol, and polyurethane showed excellent fire resistance performance in that order.

• Journal of the Korean Wood Science and Technology
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• 제51권2호
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• pp.81-97
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• 2023

The aim of this study were to evaluate tannin resorcinol formaldehyde (TRF) for the preparation of cross-laminated timbers (CLTs) made from fast-growing tree species and to analyze the physical and mechanical properties of CLTs. TRF copolymer resin was prepared by using the bark extracts of Swietenia mahagoni (L.) Jacq. It was observed that the TRF adhesive possessed less solid content (23.59%), high viscosity (11.35 poise), and high pH values (10.0) compared to the standard phenol resorcinol formaldehyde. The TRF adhesive was applied to produce CLTs with the addition of 15% tapioca and flour as an extender. The six-layered CLTs were produced from sengon (Falcataria moluccana Miq.), jabon [Anthocephalus cadamba (Roxb) Miq.], coconut (Cocos nucifera L.), and the combination of coconut-jabon and coconut-sengon wood. The analysis of variance revealed that the layer composition of CLT significantly affected the physical and mechanical properties of the beam. While the modulus of rupture met the standard, the moisture content and modulus of elasticity values did not fulfill JAS 1152-2007. All of the CLTs produced in this study demonstrated low formaldehyde emission, ranging from 0.001 mg/L to 0.003 mg/L, thereby satisfying the JAS 1152 for structural glue laminated timber.

• 한국가구학회지
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• 제12권2호
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• pp.1-10
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• 2001

As finger joint method has a high rate of yield and high strength and ease in working, it has been widely used as an end joint method for solid wood and wood based-material. Therefore, we end-joined the material of Pinus densiflora, Quercus variabilis and populus euramericana with polyvinyl acetate adhesive and resorcinol phenol resin adhesive. The effect of difference (0, 0.15, 0.3, 0.45mm) between the dimensions of tip width and root width of the finger (DTRW) on bending strength properties was as follows: 1. In the case of polyvinyl acetate adhesive, DTRW had no effect on bending modulus of elasticity(MOE) and modulus of rupture(MOR) of the three kinds of species, because their bonding layers were destroyed by slippage, not their woody parts. 2. In the case of resorcinol phenol resin adhesive, the material of Quercus variabilis showed an optimal result at 0.15 or 0.3 of DTRW, while the poplar did at 0 of DTRW 3. The differences in efficiency ratio of bending MOR of populus euramericana, Pinus densiflora and Quercus variabilis species according to the kind of adhesive were 13-29%, 23-30% and 45-53%, respectively.

• Journal of the Korean Wood Science and Technology
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• 제39권4호
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• pp.344-350
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• 2011

라디에타소나무 단판적층재(LVL)를 제조함에 있어서, CuAz 및 ACQ 방부처리와 비처리, 수성비닐우레탄 접착제와 페놀변성 리조시놀수지 접착제의 상온경화형 접착제를 적용함에 따른 밀도경사, 접착 강도성능 및 내부후성(방부효력)을 살펴보았다. 결과, LVL의 밀도경사에서 접착층 주변이 원추형으로 밀도가 커지는 경사패턴을 보였다. 접착성은 수성비닐우레탄 접착의 경우, 자비반복시험 후 전층이 박리되거나, 일부 층이 박리하고 할렬 틈새 현상이 일어났다. 페놀변성 리조시놀수지 접착제 접착의 경우, 자비반복시험 후 접착층의 응력이 큰데 연유한 굽음과 상하 접착층 사이의 단판의 수직할렬 현상이 있었으나, 접착층의 박리나 할렬이 거의 발견되지 않아 침지박리접착력은 높은 것으로 판단되었다. 한편, 방부효력시험에 있어서, 수성비닐우레탄 접착제로 적층한 LVL의 경우 갈색부후균에 의한 부후도가 백색부후균보다 크게 나타났다. 페놀변성 리조시놀수지 접착제로 LVL을 제조한 경우에는 갈색부후균에 의한 질량감소가 적었고, 약제를 처리하지 않더라도 그 피해가 낮았으며, 약제처리한 것은 질량감소율 0 수준을 보일 정도로 방부효력이 큰 것을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.79-85
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• 1992

아까시나무로부터 두종류의 flavanone인 7, 3', 4' - trihydroxy flavanone과 3, 7, 3', 4', 5' - pentahydroxy flavanonol이 단리되어 $^{13}C$ NMR에 의해 구조가 규명되었다. flavanone은 resorcinol A-ring과 Catechol B-ring으로, flavanonol은 resorcinol A-ring 및 pyrogallol B-ring으로 구성되고 있다.

• 한국염색가공학회지
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• 제4권3호
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• pp.116-121
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• 1992

This paper is on for a material to replace the petroleum-based resins used as adhesives for the fiber in rubber composite materials. The study limited to the reaction properties of tannin with formaldehyde. Tannin-formaldehyde(TF) reactions were carried out in aqueous media. Rates of reaction were strongly dependent on concentration, temperature, pH, and the mole ratio of tannin to formaldehyde. Viscosities of reaction mixtures were followed up to gelation. The reactivity of tannin-formaldehyde resins was greater than that of resorcinol-formaldehyde resins. To formulate an adhesive, a styrene-butadiene-vinyl pyridine terpolymer latex(L) was added to the TF. This preliminary results suggest that the condensed tannins have considerable promise as substitutes for resorcinol used in resin formulation for bonding of fiber to rubber.

• Journal of the Korean Wood Science and Technology
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• 제47권3호
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• pp.253-264
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• 2019

This study characterized the chemical compounds in tannin from mangium (Acacia mangium) bark extract and determined the physical-mechanical properties of glued laminated timber (glulam) made from sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), and mangium wood. The adhesives used to prepare the glulam were based on mangium tannin and phenol resorcinol formaldehyde resin. Five-layer glulam beams measuring $5cm{\times}6cm{\times}120cm$ in thickness, width, and length, respectively, were made with a glue spread of $280g/m^2$ for each glue line, cold pressing at $10.5kgf/cm^2$ for 4 h and clamping for 20 h. Condensed mangium tannin consisted of 49.08% phenolic compounds with an average molecular weight of 4745. The degree of crystallinity was 14.8%. The Stiasny number was 47.22%. The density and the moisture content of the glulams differed from those of the corresponding solid woods with mangium having the lowest moisture content (9.58%) and the highest density ($0.66g/cm^3$). The modulus of rupture for all glulam beams met the JAS 234-2003 standard but the modulus of elasticity and the shear strength values did not. Glulam beams made with tannin had high delamination under dry and wet conditions, but glulam made from sengon and jabon wood met the standard's requirements. All glulam beams had low formaldehyde emissions and were classified as $F^{****}$ for formaldehyde emissions according to the JAS 234 (2003) standard.