• Journal of Adhesion and Interface
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• v.17 no.2
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• pp.67-71
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• 2016

In this study, low-viscosity polyurethane hot-melt were synthesized with polyether polyol / polyester polyol, 4,4-dicyclohexylmethane diisocyanate ($H_{12}MDI$), 2-butanone oxime (MEKO) to improve the properties and peel strength. The properties of the synthesized low-viscosity polyurethane hot-melt was evaluated through FT-IR, viscosity meter and UTM. When the content of the reactive diluent increases and the NCO-blocked prepolymer decreases, the viscosity of low-viscosity polyurethane hot-melt adhesive was increased. When the ratio of OH-terminated oligomer, NCO-blocked prepolymer and content of reactive diluent is 1 : 0.5 : 0.5, low-viscosity polyurethane hot-melt showed 1.1 kgf/cm peel strength.

• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.62-66
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• 2011

In this study, we synthesized a excellent adhesive chlorinated polyolefin (CPO)-g-$\beta$-carboxy ethyl acid ($\beta$-CEA) by radical polymerization. Also, we prepared low-level toxic primer for polypropylene (PP) using CPO-g-$\beta$-CEA and studied toxic and adhesion property. We identified the graft structure and properties of the prepared chlorinated polyolefin-g-$\beta$ CEA using FT-IR, DSC, UTM. Graft ratio were optimum value at 5 wt% $\beta$-CEA contents in CPO-g-$\beta$ CEA. And the primer for PP was prepared with CPO-g-$\beta$ CEA and adhesive builder PX-95 content. Finally, optimum peel strength obtained when PX-95 contents was 3 wt%.

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.422-429
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• 1992

The morphology and adhesion properties of rubber compounds containing resorcinol formaldehyde(RF) resin and hexamethoxymethylmelamine(HMMM) used in adhesion of rubber to brass-plated steel cord was investigated. The resins were spherical particles about $2000{\AA}$ diameter and distributed in rubber compounds homogeneously, and the cured compound with steel cord showed migration of resin to steel cord. Also, modulus was increased with increasing HMMM contents. The loss of adhesion between rubber and steel cord was likely to be at initial stages by thermal aging. Considering the physical properties, suability of adhesion layer and thermal aging property, optimum ratio of RF resin and HMMM was 1 : 0.9.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.182-189
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• 2010

The strengthening performance of FRPs(Fiber Reinforced Polymers) is directly affected by the environmental conditions such as freezing-thawing and moisture because FRPs are usually bonded on the concrete surface. It is, therefore, strongly required to evaluate a durability of bond between FRPs and concrete as well as FRP materials itself. The freezing-thawing resistance of FRPs is evaluated in this study with the variables of freezing-thawing conditions, types of FRP and freezing-thawing cycles. From the test results, it is found that tensile strength and pull-off strength of CFRP are not affected by the freezing-thawing. On the other hands, those of GFRP show a little degradation because of continuous water immersion during thawing process. But, cautions are needed on the bond durability between FRPs and concrete in case of continuous water supplying from adjacent to the concrete.

• Journal of Adhesion and Interface
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• v.1 no.1
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• pp.38-46
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• 2000

A novel diamine monomer, containing fluorine and phosphine oxide, bis(3-aminophenyl) 3,5-bis(trifluoromethyl) phenyl phosphine oxide (mDA6FPPO), was prepared via Grignard reaction, and utilized to prepare polyimides with dianhydrides such as PMDA, 6FDA, BTDA or ODPA, by the conventional two-step route; preparation of poly(amic acid), followed by solution imidization. The polyimides were characterized by FT-lR, NMR, DSC and DMA, with intrinsic viscosity, and adhesive properties were also evaluated. A phosphine oxide containing monomer, bis(3-aminophenyl) phenyl phosphine oxide (mDAPPO) a nd a commercial 3,3'-diamino diphenyl sulfone (mDDS) were also used for comparison. The polyimides with mDA6FPPO exhibited high $T_g$, excellent solubility, and good adhesive properties.

• Journal of Adhesion and Interface
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• v.4 no.1
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• pp.18-27
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• 2003

Interfacial properties and microfailure degradation mechanisms of the oxygen-plasma treated biodegradable poly(p-dioxanone) (PPDO) fiber/poly(L-lactide) (PLLA)composites were investigated for the orthopedic applications as implant materials using micromechanical technique and surface wettability measurement. PPDO fiber reinforced PLLA composite can provide good mechanical performance for long hydrolysis time. The degree of degradation for PPDO fiber and PLLA matrix was measured by thermal analysis and optical observation. IFSS and work of adhesion, $W_a$ between PPDO fiber and PLLA matrix showed the maximum at the plasma treatment time, at 60 seconds. Work of adhesion was lineally proportional to the IFSS. PPDO fiber showed ductile microfailure modes at We initial state, whereas brittle microfailure modes appeared with elapsing hydrolysis time. Interfacial properties and microfailure degradation mechanisms can be important factors to control bioabsorbable composites performance because IFSS changes with hydrolytic degradation.

• Journal of Adhesion and Interface
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• v.22 no.1
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• pp.16-21
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• 2021

In the aircraft industry, anti- and de-icing are one of very important techniques for the safety. The anti-icing technique had not been studied while de-icing technique had been not only researched enough but applied to aircraft industry. In this work, surface roughness and energies of polyurethane (PU) topcoat were controlled with 3 different nanoparticles which was coated to PU topcoat. It was evaluated via static contact angle using distilled water. The adhesion property of 3 nanoparticles was evaluated directly using adhesion pull-off test. The color gamut of nanoparticle coated PU topcoat was also evaluated with 3 different nanoparticles. It was determined using RGB color degree variation between neat PU topcoat and coated nanoparticle. Finally, the optimized nanoparticle was determined to manufacture hydrophobic surface and to maintain color of neat PU topcoat for the aircraft.

• Composites Research
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• v.34 no.2
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• pp.108-114
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• 2021

Graphene flakes are generally mass-produced by converting graphene oxide into reduced graphene oxide using chemical or thermal reduction. These graphene flakes can be stacked to form a free-standing graphene paper, which can be used for various applications. However, a graphene paper lacks stretchability, which hinders its application in stretchable devices. In this work, we introduced wrinkles in a graphene paper to make it stretchable. A graphene paper fabricated by vacuum-filtering a graphene dispersion was placed on a pre-stretched adhesive film. When the pre-stretched adhesive film returned to the original state, the graphene paper was wrinkled. The effect of the pre-stretching and wet condition of the graphene papers was experimentally investigated by using scanning electron microscopy. In addition, we observed the change of the period of the wrinkles in the graphene paper depending on the pre-stretching.

• Journal of Adhesion and Interface
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• v.21 no.4
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• pp.135-142
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• 2020

Recently, people's interest in eco-friendly plastics derived from nature to replace petroleum-based plastics is increasing due to environmental problems such as microplastics. In line with this trend, eco-friendly adhesives using natural materials and processes are also being developed in the adhesive field. Among them, maltose is a natural substance derived from starch and is the main component of starch syrup used as a food additive. Due to its lower molecular weight than starch, it is easily soluble in water, and above all, there is a possibility that it can be copolymerized with other monomers through solution polymerization. However, researches related to the application of maltose to adhesives are very rare. In this study, after modifying maltose using acrylic anhydride, the product was analyzed through FT-IR and H-NMR. And the modified maltose was copolymerized with two kinds of acrylic monomers. The synthesized adhesive was applied on the wood and the adhesive performance were investigated.

• Composites Research
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• v.21 no.4
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• pp.7-14
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• 2008

Prediction of the load-bearing capacity of an adhesive-bonded Joint is of practical importance for engineers. This paper introduces interface fracture mechanics approach to predict the load-bearing capacity of composite metal bonded joints. The adhesion strength of composite/steel bonding is evaluated in terms of the energy release rate of an interfacial crack and the fracture toughness of the interface. Virtual track closure technique (VCCT) is used to calculate energy release rates, and hi-material end-notched flexure (ENF) specimens are devised to measure the interfacial fracture toughness. Bi-material ENF specimens gave consistent mode II fracture toughness $(G_{IIc})$ values of the composite/steel interface regardless of the thickness of specimens. The critical energy release rates of double-lap joints showed a good agreement with the measured fracture toughness. Therefore. the energy-based interfacial fracture characterization can be a practical engineering tool for predicting the load-bearing capacity of bonded joints.