• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.111-114
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• 2003

Thermosets are highly cross-linked polymers with a three-dimensional molecular structure. The network structure gives rise to mechanical properties, however, one major drawback of thermosets, which also results from their network structure, is their poor resistance to impact and to crack initiation. In this study, to solve this problem, the reactive thermoplastics such as amine terminated polyetherimide (ATPEI), ATPEI-CTBN-ATPEI(ABA) triblock copolymer, CTBN-ATPEI(AB) diblock copolymer, and carboxyl group modified ATPEI was synthesized, after that blended with epoxy resin, and the carbon fiber reinforced composites were fabricated. The impact load, energy, and delamination were investigated by using drop weight impact test and C-scan test. As a results, the ABA/epoxy blend system showed good impact properties.

• Elastomers and Composites
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• v.26 no.3
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• pp.193-201
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• 1991

Epoxy resin and CTBN(carboxyl terminated butadiene acrylonitrile) rubber were reacted at $150^{\circ}C$. Epoxy mixtures containing reactant in a ratio $0{\sim}75%(wt%)$ of total liquid component were with dicyandiamide(DICY) at $130{\sim}200^{\circ}C$. Cure, thermal and adhesive properties were investigated in relation to rubber content, cure temperature, hardner content and promoter content. $CTBN{\times}13$ showed better properties in miscibility, curing time and adhesive strength. 2PZ-CNS was more excellent in Tg, and melamine was in adhesive strength. Adhesive strength represented best at rubber content $12{\times}15%$.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.177-177
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• 1996

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.973-978
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• 1997

The toughness and morphology of epoxy resin based on diglycidyl ether of bisphenol A(DGEBA) cured with of tris (dimethylaminomethy]) phenol(DMP-30) and castor oil (CO) as a toughening modifier have been studied. Mixtures of CO and an epoxy resin showed a higher miscibility than the classical CTBN modified epoxy resin. The glass transition temperature($T_g$) was decreased with the CO content and the cure temperature. It is interpreted that the networks of epoxy matrix obtained at high temperature are apparently looser and more flexible due to the lower crosslinking density. The toughness was slightly increased with the CO content at $40^{\circ}C$ of curing temperature. The toughness increased with increasing the cure temperature and CO content.

• Journal of Adhesion and Interface
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• v.5 no.2
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• pp.1-7
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• 2004

A novel carboxyl terminated butadiene-acrylonitrile (CTBN) modified, low temperature cure epoxy film adhesive was developed in this paper. It can be cured at as low as $75^{\circ}C$ for 4 hours with a pressure of 0.1MPa. After post cure at $120^{\circ}C$ for 2 hours, the bonding strengths of Phosphoric Acid Anodizing(PAA) surface treated aluminum adherend were similar to those of structural film adhesives curing at $120^{\circ}C$. It is suitable to bond both metal/composite laminate-to-laminate and laminate to honeycomb structure.

• Applied Chemistry for Engineering
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• v.1 no.2
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• pp.232-239
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• 1990

${\gamma}$-Glycidoxy propyl trimethoxy slilane, CTBN rubber(carboxyl terminated butadiene acrylonitrile rubber) and GMA(glycidyl methacrylate) were reacted with the surface of silica one by one in existence of TEA(triethylamine) or BPO(benzoyl peroxide). The amount of reactant was 2.5~5.8% of treated silica weight. The treated silica was mixed with epoxy resin and MTHPA(methyltetrahydrophthalic anhydride) in the range of 0~60% (wt. %) of total component. The flexural and thermal properties were tested for cured products. In filler content 35~55%, the using of silica treated with silane/rubber or silane/rubber/vinyl represented 25% higher flexural strength, 5% lower flexural modulus and 13% higher than mixing liquid rubber 3% with epoxy resin containing untreated silica.

• Elastomers and Composites
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• v.56 no.3
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• pp.179-186
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• 2021

Carbon-based nanofillers, including nanodiamond (ND) and carbon nanotubes (CNTs), have been employed in epoxy matrixes for improving the toughness, using the tow prepreg method, of epoxy compounds for high pressure tanks. The reinforcing performance was compared with those of commercially available toughening fillers, including carboxyl-terminated butadiene acrylonitrile (CTBN) and block copolymers, such as poly(methyl methacrylate)-b-poly(butyl acrylate)-b-poly(methyl methacrylate) (BA-b-MMA). CTNB improved the mechanical performance at a relatively high filler loading of ~5 phr. Nanosized BA-b-MMA showed improved performance at a lower filler loading of ~2 phr. However, the mechanical properties deteriorated at a higher loading of ~5 phr because of the formation of larger aggregates. ND showed no significant improvement in mechanical properties because of aggregate formation. In contrast, surface-treated ND with epoxidized hydroxyl-terminated polybutadiene considerably improved the mechanical properties, notably the impact strength, because of more uniform dispersion of particles in the epoxy matrix. CNTs noticeably improved the flexural strength and impact strength at a filler loading of 0.5 phr. However, the improvements were lost with further addition of fillers because of CNT aggregation.

• Composites Research
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• v.20 no.4
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• pp.1-8
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• 2007

In this study, carbon fiber reinforced polymeric (CFRP) composites with different resin composition were manufactured and resin formulation in composite materials were presented through tensile tests for cryogenic use. Thermo-mechanical cyclic loading (up to 6 cycles) was applied to CFRP unidirectional laminate specimens from room temperature to $-150^{\circ}C$. Tensile tests were then performed at $-150^{\circ}C$ using an environmental test chamber. In addition, matrix-dominant properties such as the transverse and in-plane shear characteristics of each composite model were measured at $-150^{\circ}C$ to examine the effects of resin formulation on their interfacial properties. The tensile tests showed that the composite models with large amounts of bisphenol-A epoxy and CTBN modified rubber in their resin composition had good mechanical performance at cryogenic temperature (CT).

• Elastomers and Composites
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• v.32 no.1
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• pp.11-19
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• 1997

[ ${\gamm}-Glycidoxy$ ] propyl trimethoxy silane, CTBN rubber(carboxyl terminated butadiene acrylonitrile rubber) and GMA(glycidyl methacrylate) were reacted on the surface of silica one by one in existence of TEA(triethylamine) or BPO(benzoyl peroxide). The amount of reactant was $2.5{\sim}5.8%$ of treated silica weight. The treated silica was mixed with epoxy resin and MTHPA(methyl tetrahydro phthalic anhydride) in the range of $0{\sim}60%$(wt.%) of total component. The thermal properties were tested for cured products. By using silica treated with silane/rubber or silane/rubber/vinyl, comparing with 3% of rubber mixed directly, it had 13% higher $T_g$ and 10% lower thermal expansion coefficient at $35{\sim}55%$ of silica contents.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.49-52
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• 2005

In the development of a propellant tank using liquid oxygen and liquid hydrogen, the improvement of microcrack resistance of carbon/epoxy composites is necessary for the application of a composite material to tank structures. In this research, two types of carbon/epoxy composites with different matrix systems were tested to measure interlaminar shear strength (ILSS), one of the material properties to evaluate fiber-matrix interface adhesion indirectly. Short beam specimens were tested inside an environmental chamber at room temperature(RT) and at cryogenic temperature( - 150 $^{\circ}C$) respectively. Results showed that the matrix system with large amount of bisphenol-A and CTBN modified rubber had good performance at cryogenic temperature.