• Macromolecular Research
• /
• v.14 no.3
• /
• pp.300-305
• /
• 2006

The chemical structure of a semi-aromatic polyimide-I, which was prepared by the chemical imidization of cyclopentanetetracarboxylic dianhydride and 2,2-bis(4-aminophenyl)hexafluoropropane, was characterized by $^{13}C-NMR$ spectroscopy. The chemically imidized polyimide-I was used for the preparation of a photosensitive polyimide (PSPI) through the addition of benzophenone and benzophenone oxime hexamethylene diurethane (BOHD), a photobase generator containing oxime-urethane groups. The polyimide-I film containing benzophenone and BOHD was not soluble in 2.38 wt% tetrabutylammonium hydroxide solution in $H_2O$. However, it became soluble following irradiation with 310 nm UV light. A positive tone image with a resolution of $5{\mu}m$ was obtained with this PSPI, having sensitivity($D_c$) of $1.2J/cm^2$ and contrast(${\gamma}_p$) of 1.08. Thus, a polyimide, which is not intrinsically photosensitive, can become photosensitive through the addition of a photobase generator containing oxime-urethane groups as a photosensitive compound.

• Journal of the Semiconductor & Display Technology
• /
• v.16 no.3
• /
• pp.87-92
• /
• 2017

Poly(urethane acrylate) siloxane oligomers with Interpenetrating polymer networked nanoparticles were prepared to synthesize hard coating solution by reaction with isophorone diisocyanate(IPDI) of 1, 2, 3, 4 phr. The structures and molecular weights of the synthesized solutions were characterized by IR spectroscopy and gel permeation chromatography, respectively. In the cross-cut test for the adhesion, all the solutions showed good adhesion of 5B regardless of the content of IPDI and film thickness. The addition of 1 phr IPDI resulted in the best pencil hardness. The IPDI combined siloxane hard coating solution showed more flexibility than the siloxane solution. These results will yield the improvement in the siloxane solution using for plastic display plate.

• Journal of Power System Engineering
• /
• v.22 no.1
• /
• pp.64-71
• /
• 2018

Currently, functional patterns are formed by screen printing on stretchable films, and they are applied to wearable and stretchable devices. In this study, three types of silver paste were prepared using three polyester binders with different Tg and molecular weights in order to impart elasticity to the conductive pattern itself. Rheological properties and DSC measurements were performed for each silver paste. Then, each silver paste was screen printing and cured by an IR dryer to evaluate adhesive strength, pencil hardness, resistance and surface shape change according to strain. As a result, it was found that the silver paste using a binder with a low Tg and a high molecular weight has the smallest resistance change depending on the strain. Namely, it was found that it is most preferable to use a binder with a low Tg and a high molecular weight as the stretchable electrode.

• Journal of Integrative Natural Science
• /
• v.6 no.4
• /
• pp.211-214
• /
• 2013

In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4-ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly-urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that HF treatment is not desirable for the synthesis of a high quality PEDOT thin film via vapor phase polymerization method. Rather, sole treatment with plasma noticeably improved the quality of APS-SAM on glass surface. As a result, a highly dense and smooth PEDOT thin film was grown on uniform oxidant film-coated APS monolayer surface.

• Textile Coloration and Finishing
• /
• v.25 no.1
• /
• pp.70-74
• /
• 2013

For amine gas detection, we incorporated two well-known isomers, 2-chloro-3,5-dinitro-benzotrifluoride and 4-chloro-3,5-dinitro-benzotrifluoride, in polyurethanes. Nanoweb and thin film were prepared by electrospinning and lamination, respectively, in order to compare their sensing behaviors. Moreover, we studied photophysical property using UV-Vis spectrometer and observed surface area through scanning electron microscope to compare between the Nanoweb and thin film. We found out that nanowebs exhibited high sensitivity specifically to primary amine gas.

• Applied Chemistry for Engineering
• /
• v.19 no.5
• /
• pp.547-553
• /
• 2008

To achieve the ideal performances of paint film, resins and hardeners have to be chosen and designed in a proper way depending on the exposure circumstance of substrate and the requested physical properties. Six different kinds of clear paints were made in this experiment using alkyd polyol, polyester polyol, polyester modified acrylic polyol and another 3 acrylic polyol resins whose $T_g$ and OH value were partially modified. Then the tests for chemical, physical, and mechanical properties were measured after forming the paint films using aliphatic and aromatic polyisocyanate. The viscosity and elasticity of paint film were then measured in terms of gel point and $tan{\delta}$ using Rheometer and DMA. Through this viscoelastic characteristic test of polyurethane resin, we were able to choose the adequate resins and hardeners which are the most important in the top and primer painting system of urethane paint and, as a result of observing the physical, mechanical, and chemical properties of paint film by urethane, we have finally reached the conclusion that we could apply the proper polyol to top and primer paint for developing the polyurethane paint system.

• Elastomers and Composites
• /
• v.33 no.5
• /
• pp.324-334
• /
• 1998

SBR, polyurethane, acryl and epoxy latex were seperately mixed with ethylene-vinylacetate emulsion(EVA) in the range of $0{\sim}50%$ (wt.% ). For the mixtures, the various physical properties were examined. The viscosity of mixtures was mainly influenced by compatability with EVA emulsion, was decreased within 20% (wt.% ) of latex content, and showed the similar values over 20% (wt.% ) of latex content. The workable time of cement mixtures was mainly depended on the reactivity with cement. The formation of film could be only within $30{\sim}40$ minutes from mixing cement. The tack-free time of mixtures was influenced by the sorts of resin and the quantity of cement. The slow order of tack-free time was epoxy mixtures>SBR mixtures>urethane mixtures>acryl mixtures. The pencil hardness of mixtures was $4B{\sim}2H$, represented higher value in cement mixtures than in emulsion state.

• Transactions of the Korean hydrogen and new energy society
• /
• v.28 no.1
• /
• pp.77-84
• /
• 2017

In this study, Poly-urethane acrylate (PUA) was synthesized by the reaction between Polycaprolactonetriol (PCLT) and Isophorone dissocyanate (IPDI) and hybridized with inorganic materials. Tetraethylortho silicate (TEOS) and nano clay (Closite 20A) were used as inorganic particles. For the hybridization of TEOS with PUA, sol-gel method is used, in which TEOS is made into spherical particle in the firsthand. In the case of Nano clay, hybridization is carried out through the dispersion as Nano clay has a layered structure. The solution of PUA hybrid was made into a film after UV curing and its thermo and electrical properties were measured. The experimental analysis and result demonstrate that the PUA hybrid shows an improved thermal properties and lower dielectric constant than that of the non-hybrid PUA. The trend of improved properties was different depending on structure of inorganic materials.

• Textile Coloration and Finishing
• /
• v.27 no.2
• /
• pp.126-131
• /
• 2015

Silica-polyurethane hybrid breathable films were prepared and their breathabilities were assessed. Appropriately aggregated silica was prepared through sol-gel reaction of water glass and its particle size ranged 360~500nm. The polyurethane dispersion was prepared by the reaction of isophorone diisocyanate(IPDI) as diisocyanate and polytetramethylene glycol(PTMG) and dimethylol propionic acid(DMPA) as polyol, particle size ranging 30~120nm. The reaction between isocyanate and hydroxyl group to form urethane bonding was checked by the intensity of the stretch peak of isocyanate at $2270cm^{-1}$ in the FT-IR. The silica was incorporated into polyurethane dispersion and casted into film. It was shown that the incorporated silica(1~5wt.%) increased water vapour permeability of the films by 30~100%, and decreased the hydrostatic pressure by 10~40%. From the results, it could be concluded that the appropriate hybridization of silica can increase the breathability of polyurethane dispersion film, while minimizing the loss of hydrostatic pressure.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2011.11a
• /
• pp.16-16
• /
• 2011

기존의 얇고 가벼운 기능성 투습방수 film은 각종 등산복이나 육해공군전투복, 경찰복, 소방복 등에 폭넓게 이용되고 있다. 그러나 현재의 이런 제품들은 뛰어난 투습방수성을 나타내지만 눈, 비, 이슬 등과 같은 수분과 만날 경우 필름 고분자 구조의 Swelling으로 표면의 불규칙한 요철현상이 생기며, 이는 제품의 불량으로 문제시 되고 있다. Swelling이 생기지 않는 친수성 Urethane film이 스키복으로 많이 상용되고 있기는 하지만 두께가 두껍고 무거워서 움직임이 불편한 단점이 있다. 본 연구에서는 이러한 문제점들을 보완하여 얇고 가벼운 기능성 비팽윤 투습 방수 필름을 제조하였다. 제조된 비팽윤 투습 방수 필름제품은 기존의 투습 방수 필름과도 다른 독특한 Bead concrete 구조를 형성하고 있으며, 미세입자들이 서로 접합하여 우수한 투습성을 발현하며, 기저층의 모노리스 멤브레인(Monolithic film)의 적층구조로서 형성되어 있어 강도 및 투습도 등의 성능이 제어되고, 수분 흡수에 따른 팽윤현상이 발생하지 않는다.