• Elastomers and Composites
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• 제22권4호
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• pp.305-313
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• 1987

In this study, as one of the developing ways of the functional elastomer, improvement of the functionality of 1-Chlorobutadiene-Butadiene Copolymer(CB-BR) was attempt through curing reaction by moisture. The curing reaction of CB-BR was determined an use of $\gamma$-Aminopropyltriethoxysilane(APS) and $\gamma$-Aminopropylmethyldiethoxysilane(ADS) as a crosslinking agent with filler at so the uncrosslinked elastomer was exposured in the air and curing reaction by moisture in the air was studied. The results obtained are as follows. 1. APS was more efficient than ADS as a crosslinking agent for CB-BR 2. Optimum amount of APS for moisture cured elastomer was r=1.5(at the ratio of $[APS]/[Cl^*]$) also in case(r=1.5), elastomer formed after soaking $T_{72}$ had similar physical properties with elastomer crosslinked by sulfur and it was very good. 3. Uncrosslinked elastomer(CB-BR+APS+Silica) was easily crosslinked by exposure to the air, and the physical properties was also satisfactory.

• Elastomers and Composites
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• 제23권3호
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• pp.223-229
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• 1988

The effect of triazine thiol derivative on the physical properties of silica-polychloroprene(CR) composites and glass fiber(MGF)-CR composites was investigated. Optimum cure time of the MGF composites filled with 2-dibuthylamino-4, 6-dithiol-s-triazine(DBT) was the fastest one, while maximum torque was the best in case of the silica composites filled with s-triazine-2,4,6-trithiol(TAT) on the Oscillating Disk Rheometer(ODR) test. Stress-strain curves of the composites showed that the physical properties such as 100% modulus, 300% modulus, tensile strength of the silica composites filled with DBT was very satisfactory and the silica composites filled with TAT was higher density of crosslinking than other crosslinked elastomer. In aging properties, elastomer filled DBT and TAT were progress post-curing reaction with increasing of aging time and it have been improved the tensile strength and crosslinking density.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1993년도 ACT 93
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• pp.419-423
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• 1993

• 한국산학기술학회논문지
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• 제17권1호
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• pp.433-440
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• 2016

설폰화시킨 poly(etheretherketone)(sPEEK)막의 전해질 특성을 향상시키기 위하여 sPEEK에 imidazole과 무기물인 phosphotungstic acid(PWA)를 첨가하고 용액주조법을 이용하여 복합막을 제조하였다. TGA분석을 통하여 산-염기 상호작용에 의한 물리적 가교결합이 복합막의 설폰산그룹 분해에 대한 열저항성을 향상시키고 PWA의 첨가는 복합막의 열분해에 대한 저항성을 향상시키는 것을 확인할 수 있었다. 산-염기 상호작용은 sPEEK/imidazole 복합막의 함수율과 양이온전도도 및 메탄올 투과도를 감소시켰는데 이것은 물리적 가교결합이 복합막을 견고하게 만들기 때문이다. PWA는 sPEEK/imidazole/PWA 복합막의 함수율과 메탄올 투과도는 감소시켰지만 양이온전도를 향상시켰다. 따라서 PWA는 복합막의 선택도를 향상시키는 효과를 나타내었다.

• Korea Journal of Cosmetic Science
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• 제2권1호
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• pp.11-19
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• 2020

The aim of this study is to investigate the effect of various pentapeptides on hair repair depending on the characteristics of comprising amino acids using crosslinking agents in hair. Total ten peptides were synthesized with two kinds of amino acids respectively, of which were previously categorized according to R group of the amino acids contributing to the characteristic of each peptide: STTSS (Ser-Thr-Thr-Ser-Ser), LIILL (Leu-Ile-Ile-Leu-Leu), CMMCC (Cys-Met-Met-Cys-Cys), DEEDD (Asp-Glu-Glu-Asp-Asp), RKKRR (Arg-Lys-Lys-Arg-Arg), TAMRA-STTSS, TAMRA-LIILL, TAMRA-CMMCC, TAMRA-DEEDD, and TAMRA-RKKRR. Pentapeptide alone, or pentapeptides with crosslinking agents such as polymeric carbodiimide (PCI) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were treated to chemically damaged hair. Hair diameter and break strength (N = 40/case) were measured to calculate tensile strength of hair for computing hair repair ratio, and fluorescence yields (N = 20/case) were collected for hair treated with TAMRA-peptides. The tensile strength of hair treated with pentapeptides alone, or pentapeptides with cross-linking agents is consistent with the fluorescence yield from the microscope images of the cross-sectioned hair in vision and in numerical values. Pentapeptides consisting of hydrophobic amino acids (LIILL), amino acids with sulfur (CMMCC), and basic amino acids (RKKRR) increased the tensile strength in perm-damaged hair. Pentapeptides with no extra carboxyl/amine groups in R group of amino acids resulted in no significant differences in hair strength and fluorescence yield among hairs treated with alone and with crosslinkers. Pentapeptides with extra carboxyl groups or amine groups enabled further strengthening of hair due to increased bonds within the hair after carbodiimide coupling reaction. The hair repairs of pentapeptides with various amino acid sequences were studied using crosslinking. Depending on the physical characteristics of comprising amino acids, the restoration of damaged hair was observed with tensile strength of hair and fluorescence signals upon cross-sectioned hair in parallel to possibly understand the binding tendency of each pentapeptide within the hair.

• 한국의류산업학회지
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• 제6권5호
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• pp.660-666
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• 2004

This article describes the change of hand value of chitosan crosslinked cotton fabrics. The chitosan crosslinked cotton fabrics were manufactured by mercerizing process using epichlorohydrin(ECH) as crosslinkins agent, 2% aqueous acetic acid as a solvent of chitosan and ECH, and 20% aqueous sodium hydroxide as a mercerizing agent and crosslinking catalyst. Cotton fabrics were dipped in the mixed solution of chitosan and ECH, picked up by mangle, mercerized and crosslinked in NaOH solution, and finally wash and dry. Mechanical and physical properties of the chitosan crosslinked fabric were investigated using Kawabata Evaluation System(KES) and other instruments. Tensile energy and tensile strain were decreased with the increase of the concentration of chitosan. Tensile resilience, compression resilience bending rigidity, bending hysteresis, shear stiffness, shear hysteresis, coefficient of friction, geometrical roughness, compression linearity, compressional energy, and thickness were increased with the increase of the concentration of chitosan. On the other hand, bending rigidity, bending hysteresis, coefficient of friction, geometrical roughness, compressional resilience, and thickness were increased with the increase of the concentration of crosslinking agent(epichlorohydrin).

• 폴리머
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• 제26권6호
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• pp.778-784
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• 2002

덱스트란 용액으로 필름을 제조하여 여러 가지 특성들을 살펴보았으며, 가소제 및 가교제를 첨가하거나 저온 플라스마로 표면을 처리함으로써 이러한 특성들을 향상시킬 수 있는 지를 살펴보았다. 덱스트란 필름은 기계적 강도는 우수하였으나 부스러지기 쉽고 수분에 대단히 약한 특성을 보였다 가소제를 첨가할 경우에는 유연성이 크게 개선되는 대신에 기계적 강도가 크게 약화되었다. 하지만, 가소제를 첨가한 다음 가교제로 가교시키거나 함께 첨가할 경우에는 비교적 우수한 기계적 강도와 함께 유연성을 지닌 필름이 제조되었으며, 수분에 대한 저항성도 향상되었다. 또한, 아세틸렌 플라스마로 처리할 경우 필름 자체의 특성은 크게 변하지 않으나 친수성인 표면이 소수성으로 바뀌었다.

• Elastomers and Composites
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• 제36권1호
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• pp.52-60
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• 2001

발포체의 물성은 발포체의 밀도, 사용된 폴리머의 기계적 물성과 열린 셀(open cell) 함량, 셀 크기, 셀 크기 분포, 셀 형태, 격벽의 두께 등을 포함하는 셀 구조에 의존하며 이러한 발포체의 밀도는 사용된 폴리머의 종류와 가교제의 농도, 발포제의 농도 그리고 가공 기술 및가공 조건 같은 다양한 원료물질과 가교조건에 영향을 받는다. Ethylene vinyl acetate coplymer (EVA) 발포체는 가교 발포체로서 가교속도와 발포제의 분해속도에 의해 발포특성에 영향을 받으며 이에 따라 발포체 물성에도 영향을 미친다. 본 연구에서는 가공 온도인 $155^{\circ}C$에서의 시간에 따른 발포제의 분해 속도 차이와 이에 따른 발포특성과 발포체의 물성에 대한 영향을 평가하였다. 발포제 분해 속도가 보다 느린 경우, 발포제 분해속도가 빠른 경우와 비교하여 낮은 밀도를 보여주었으며, 우수한 충격흡수성을 나타내었고 발포체의 셀 크기는 보다 균일하였다.

• 한국응용과학기술학회지
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• 제25권4호
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• pp.525-532
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• 2008

To prepare a solution type acrylic pressure-sensitive adhesive, quarter polymers were synthesized from butyl acrylate(BA), 2-ethylhexylacrylate(2-EHA) as a base monomer, methyl methacrylate(MMA) as a comonomer, each of methacrylic acid(MAA), acrylic acid(AA) as a functional monomer. Acrylic solution type pressure-sensitive adhesives(PSA's) of isocyanate derivative crosslinking PSA's were prepared by crosslinking of BEMM, BEMA with toluene-2,4-diisocyanate. The structure of adhesive was identified by FT-IR. The viscosity was measured by using Brookfield DV-III and molecular weight was measured by using gel permeation chromatography. The physical properties of polyethylene film coated with BEMMT, BEMAT were measured as a function of the concentration. As the result, BEMMT(0.6, 0.8), BEMAT(0.6) showed peel adhesion of $160{\sim}180\;g_f$/25 mm width and shear adhesion of more than 24 hours, and tackiness of $4/32{\sim}6/32$ which was relevant to commercial usage.

• 폴리머
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• 제36권1호
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• pp.29-33
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• 2012

관능성 단량체로서 acrylic acid(AA)를 사용하였고, 기본 단량체로서는 2-ethylhexyl acrylate(2-EHA)를 사용하여 용액중합의 방법으로 점착제를 합성하였다. 점착제의 점착물성 중에 AA와 경화제 함량에 따른 점착제의 표면에너지와 물성변화 연구를 조사하였다. 합성된 점착제의 구조는 FTIR을 통하여 확인하였고 점도와 분자량은 Brookfield 점도계와 GPC를 사용하여 각각 측정하였다. 분자량과 점도는 AA가 6 wt%까지는 함량증가에 따라 증가하였으며 6 wt% 이상에서는 감소하였다. 이러한 경향은 표면에너지 역시 AA 함량증가에 따라 COOH 그룹에 의한 극성 강화로 표면에너지는 증가하였다. 반면, 점착력은 분자량과 반비례 관계를 보였으며 AA 함량과 경화제 함량 증가에 따라 감소하는 경향을 나타내었다.