• Elastomers and Composites
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• 제52권1호
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• pp.81-85
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• 2017

In order to improve the water resistance, we synthesized waterborne polyurethane by using polyester polyol, poly(propylene carbonate) (PPC), 4,4'-dicyclohexylmethane diisocyanate ($H_{12}MDI$), and dimethylolpropionic acid (DMPA). The properties of the synthesized waterborne polyurethane using poly(propylene carbonate) (WPUP) were evaluated by FT-IR, $^1H-NMR$, GPC, DSC, TGA, and UTM. The mechanical properties increased while the adhesion properties decreased with the increase in the amount of PPC. The highest water resistance was shown when the ratio of polyester polyol to PPC was 9:1.

• Fibers and Polymers
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• 제4권4호
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• pp.151-155
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• 2003

The abrasion behavior of three kinds of warp knitted fabrics, which are normally used for upper sole of footwear, was evaluated. We measured the changes of mechanical and structural properties of each sample as abrasion cycle increased. Each sample showed similar trends in compression and surface properties but there were significant differences in abrasion rate among the samples. The mechanical properties showed remarkable differences with directions. The frictional coefficient (MIU) of fabric surface increased at the beginning of abrasion and decreased as abrasion cycles increased. The weight and thickness of the fabric linearly decreased with abrasion cycles. The surface roughness (SMD) and the compressional resilience (RC) decreased as abrasion cycles increased while compressional energy (WC) increased.

• 펄프종이기술
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• 제32권1호
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• pp.26-32
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• 2000

The impact of major surface chemical properties of silica sols on the retention and drainage performance of the silica based micrparticle system, Compozil was investigated using four different silica sols. And the effect of silica properties on the interactions with cationic starch and cationic plyacrylamide has also been identified. The surface charge density and the stability over pH of silica sols were increased by introducing aluminosilicate anions at surface. It was found that the charge density of silica sols determined the addition level necessary to attain the maximum retention and drainage. When silica sols were combined with cationic starch, the change density of the product was the critical properties and the degree of microagregation was of minor importance. In the cationic polyacrylamide system the degree of colloid structure appeared to be a more critcial property than the charge density of silica sols.

• Carbon letters
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• 제16권2호
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• pp.67-77
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• 2015

Carbon fibers (CFs) have a unique combination of properties which allow them to be widely used as reinforcing materials in advanced polymer composites. The mechanical properties of CF-reinforced polymer composites are governed mainly by the quality of interfacial adhesion between the CFs and the polymer matrix. Surface treatments of CFs are generally carried out to introduce chemical functional groups on the fiber surfaces, which provide the ability to control the surface characteristics of CFs. In this study, we review recent experimental studies concerning various surface treatment methods for CFs. In addition, direct examples of the preparation and properties of CF-reinforced thermosetting composites are discussed.

• Elastomers and Composites
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• 제51권4호
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• pp.269-274
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• 2016

Two different reactive silicone oligomers, hydroxylpropyl terminated PDMS (PDMS-L) and 1-(2,3-dihydroxy-propoxy)propyl terminated PDMS (PDMS-B), were synthesized through hydrosilylation reaction under Karstedt's catalyst. Using the reactive silicone oligomers, two different silicone-modified gel-coat series were prepared to investigate their thermal and mechanical properties as well as surface characteristics according to reactive silicone oligomer contents. In case of thermal stabilities and mechanical properties, the gel-coat series containing PDMS-B showed higher values than that of the gel-coat series containing the PDMS-L. The contact angle for the gel-coat containing both silicone oligomers/was increased with reactive silicone oligomer contents but there was similar surface tension between PDMS-L and PDMS-B.

• 한국의류산업학회지
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• 제3권4호
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• pp.357-361
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• 2001

This paper is concern with the effect of various conditions on mechanical properties of textile fabrics by water soluble resin treatment. Resin treatment of cotton, acetate, viscose rayon, polyester, nylon and acryl fabrics were made by aqueous resin treatment to improve the mechanical properties. The mechanical properties of fabrics, the breaking strength and strain were measured and surface reflectance was measured by color eye. The breaking strength and surface reflectance of fabrics by water soluble resin treatment showed difference by the different treatment concentration. The surface reflectance was increased by water soluble resin treatment. The breaking strength was lower in fabrics with resin treatment than fabrics with none treatment.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권5호
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• pp.206-206
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• 2003

It is hard to expect excellent electrical, mechanical and chemical properties from most of the composite materials presently used as insulators due to insufficient wettability property caused by the difference of interfacial properties between the matrix material and the reinforcer. Therefore, various interfacial coupling agents have been developed to improve the interfacial properties of composite materials. But if the wettable coupling agents are used outdoor for a long time, change in quality takes place in the coupling agents themselves, bringing about deterioration of the properties of the composite materials. In this study, glass surface was treated by plasma to examine the effect of dry interface treatment without coupling agent. It was identified that the optimum parameters for the best wettability of the samples at the time of generation of plasma were oxygen atmosphere, 0.1 torr of system pressure, 100 W of discharge power, and 3 minutes of discharge time. Also, the surface resistance rate and dielectric property were improved.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권5호
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• pp.206-212
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• 2003

It is hard to expect excellent electrical, mechanical and chemical properties from most of the composite materials presently used as insulators due to insufficient wettability property caused by the difference of interfacial properties between the matrix material and the reinforcer. Therefore, various interfacial coupling agents have been developed to improve the interfacial properties of composite materials. But if the wettable coupling agents are used outdoor for a long time, change in quality takes place in the coupling agents themselves, bringing about deterioration of the properties of the composite materials. In this study, glass surface was treated by plasma to examine the effect of dry interface treatment without coupling agent. It was identified that the optimum parameters for the best wettability of the samples at the time of generation of plasma were oxygen atmosphere, 0.1 torr of system pressure, 100 W of discharge power, and 3 minutes of discharge time. Also, the surface resistance rate and dielectric property were improved.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.23-24
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• 2020

In this study, effect of surface modification of waste glass for fine aggregates on the mechanical properties and alkali silica reaction of mortar was analyzed. As a result, it was confirmed that the incorporation of waste glass fine aggregate decreases the mechanical properties of the mortar and increase the alkali silica reaction expansion. On the other hand, the surface modification of the waste glass fine aggregate is effective in improving this problem. However, unlike green and brown waste glass, it is judged that an additional experiment to determine the cause is necessary for white waste glass where alkali silica reactive expansion occurs extremely.

• 한국의류산업학회지
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• 제14권4호
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• pp.677-683
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• 2012

1-octanethiol and vinyl acetate telomers ($R_8S$-nVAc) were synthesized and hydrolyzed with sodium hydroxide subsequently, 1.2-epoxyhexane was then introduced to the telomers. In addition, we prepared cotelomers of multi-alkylated nonionic surfactants with a molecular structure of xRnMA-yVA (x; hydrophobic group, y; hydrophilic group, MA; methacrylic ester, VA; vinyl alcohol, R; and alkyl group) and cross-linked with sodium tetraborate decahydrate. Their active surface properties were investigated by several techniques such as surface tension, foaming property, and emulsification power measurements. The surface tension of $R_8S$-8.8VA decreased without the introduction of 1.2-Epoxy hexane, and the degree of emulsification and foaming abilities of $R_8S$-8.8VA increased without the introduction of 1.2-Epoxy hexane. However, the differences were insignificant. The epoxy groups were attached to a $R_8S$-8.8VA cotelomer with a limited variation of the active surface properties. The surface tension of $1.1R_6MA$-8.8VA decreased after cross-linking subsequently, the degree of emulsification and foaming abilities of $1.1R_6MA$-8.8VA increased after cross-linking. However, there was no clear difference between them. The B-O bonds were attached to a $1.1R_6MA$-8.8VA cotelomer with a limited variation of the active surface properties.