• Korean Chemical Engineering Research
• /
• 제46권4호
• /
• pp.669-675
• /
• 2008

카본블랙은 토너수지, 잉크 및 복합재료 등에 광범위하게 산업적으로 응용되고 있다. 본 연구에서는 분산 안정성을 증대시키기 위하여 카본블랙을 상 이동 촉매(phase transfer catalyst)를 이용한 상온에서의 산화반응을 통하여 카본블랙(CB)-수산화기(OH)를 제조하여 이에, silane coupling-agent인 p-methylacryloxypropyltrimethoxysilane를 grafting시켜 말단에 이중결합을 가진 구조를 도입하였다. 이렇게 표면개질된 카본블랙을 미니유화중합법을 이용하여 고분자로 캡슐화를 진행하였다. 이러한 과정을 통하여 평균직경 100~500 nm 크기의 하이브리드 미립자를 제조하였다. 중합과정에 있어서 카본블랙의 표면 개질의 영향, 모노머의 종류, 개시제 및 유화제의 캡슐화 반응에 미치는 영향을 연구하였다.

• Macromolecular Research
• /
• 제12권6호
• /
• pp.608-614
• /
• 2004

Isotactic polypropylene (PP) surfaces were modified with argon and oxygen plasmas using a radio­frequency (RF) glow discharge at 240 mTorr and 40 W. The changes in topography and surface structure were investigated by atomic force microscopy (AFM) in conjunction with specular reflectance of infrared (IR) microspectroscopy. Under our operating conditions, the AFM image analysis revealed that longer plasma treatment resulted in significant ablation on the PP surface, regardless of the kind of plasma employed, but the topography was dependent on the nature of the gases. Specular reflectance IR spectroscopic analysis indicated that the constant removal of surface material was an important ablative aspect when using either plasma, but the nature of the ablative behavior and the resultant aging effects were clearly dependent on the choice of plasma. The use of argon plasma resulted in a negligible aging effect; in contrast, the use of oxygen plasma caused a noticeable aging effect, which was due to reactions of trapped or isolated radicals with oxygen in air, and was partly responsible for the increased surface area caused by ablation. The use of oxygen plasma is believed to be an advantageous approach to modifying polymeric materials with functionalized surfaces, e.g., for surface grafting of unsaturated monomers and incorporating oxygen-containing groups onto PP.

• Elastomers and Composites
• /
• 제29권5호
• /
• pp.444-452
• /
• 1994

Emulsion graft copolymerizations of vinyl monomers, butyl acrylate(BA), methyl methacrylate(MMA), 2-ethylhexyl acrylate (EHA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate(HEMA), methacrylonitrile(MAN), dimethylaminoethyl methacrylate(DAMA) or 2-vinyl pyridine(VP), onto carboxyl-terminated SBR latex were carried out under different experimental conditions. In case of synthesizing SBR-g-poly(butyl acrylate), the degree of grafting was increased with increasing the amount of emulsifier, polymerization temperature and the amount of initiator. Pull-out strength of resorcinol-formaldehyde-latex(RFL) adhesives formulated with modified latexes was very higher than that of RFL adhesive formulated with ungrafted latex. When the modified latexes with GMA, HEMA, MAN, DAMA or VP were used, the break occurred at cords. Peel strength of RFL adhesives formulated with SBR-g-poly(GMA), SBR-g-poly(HEMA) or SBR-g-poly(VP) was higher by about 1.3 times than that of RFL adhesives formulated with unmodified SBR against nylon cord and was higher by about 2.0 times against polyester cord.

• 한국실내디자인학회논문집
• /
• 제21권1호
• /
• pp.30-39
• /
• 2012

The essence of brand identity is to draw an interrelation between user and brand based on user's desire. The housing cultural center is focused on brand identity for satisfaction of user. The purpose of this study is to inquire out the expression characteristics of brand Identity in housing cultural center according to analyze previous studies and case studies. The results of this study are summarized as follows. 'Uniqueness' is directly expressed through brand name or logo or through brand colors. 'Experience' is expressed as auditive expression through stimulation using a body and providing music. 'Relationship' has provided a communication environment or created relationship with brand by leading interaction with others. 'Estheticism' has increased visual satisfactory level by aesthetically sublimating lighting direction or form. 'Functionality' is expressed by providing various programs through smooth flow plan and grafting with the latest technology. 'Non-dailiness' has affected memory territory by inducing curiosity and astonishment through space modification or new and contrasting direction. The housing cultural center needs to be planned as a space where interaction of user and brand will be initiatively activated sensationally and psychologically by pursuing user-oriented brand identity.

• 한국염색가공학회지
• /
• 제11권2호
• /
• pp.27-37
• /
• 1999

Polypropylene(PP) films were treated with plasma glow discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PP film surfaces were subsequently used for the graft polymerization of acrylic acid and acrylamide in an aqueous solution by heating, respectively. Introduction of acrylic acid and acrylamide on the PP film could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. And introduction of functional group could be confirmed by weight analysis and ESCA. The water contact angle(90$^{\circ}$) of PP film was constant, irrespective of elapsed time, while plasma-treated and functional monomer-grafted PP films were slowly increased with elapsed time, showing the rearrangement of surface polar groups in air condition. The water contact angle$(90^\circ)$ of PP film was decreased by the plasma treatment$(56^\circ)$ and further decreased by the grafting of acrylic acid$(34^\circ)$ and acrylamide$(37^\circ)$, indicating increased hydrophilicity of the modified surfaces. The water contact angle of plasma-treated PP film increased a little as time elapsing. The half-life periods of surface voltage on acrylic acid-(31sec) and acrylamide-grafted PP(42sec) were significantly decreased when compared to those on PP(950sec) and plasma-treated PP film(241sec). In the experiments using acid, basic and disperse dyes, absorbance and $\Delta{E}$ values of functional monomer-grafted PP films were significantly increased than that of oxygen plasma-treated one.

• Carbon letters
• /
• 제13권4호
• /
• pp.212-220
• /
• 2012

Orange peel (OP) exhibits a sorption capacity towards anionic dyes such as reactive blue 19 (RB19). Cetyltrimethylammonium bromide (CTAB) as a cationic surfactant was used to modify the surface nature of OP to enhance its adsorption capacity for anionic dyes from an aqueous solution. Four adsorbents were investigated: the OP, sodium hydroxide-treated OP (SOP), CTAB-modified OP and CTAB-modified SOP. The physical and chemical properties of these sorbents were determined using nitrogen adsorption at 77 K and by scanning electron microscope and Fourier transform infrared spectroscopy techniques. The adsorption of the RB19 dye was assessed with these sorbents at different solution pH levels and temperatures. The effect of the contact time was considered to determine the order and rate constants of the adsorption process. The adsorption data were analyzed considering the Freundlich, Langmuir, Elovich and Tempkin models. The adsorption of RB19 by the assessed sorbents is of the chemisorption type following pseudo-first-order kinetics. CTAB modification brought about a significant increase in RB19 adsorption, which was ascribed to the grafting of the sorbent with a cationic surfactant.

• Fibers and Polymers
• /
• 제4권3호
• /
• pp.107-113
• /
• 2003

The branched polypropylene (b-PP) was prepared by melt blending process with initiator, antioxidant, and functional monomers to improve the melt strength through the melt grafting. The melt flow index (MFI) of the b-PP was increased with increasing the initiator content. On the introduction of the alkylamine as the branching agents the MFI of the b-PP was increased, while that of the b-PP with the pentaerythritol triacrylate (PT) was decreased. It may be caused by the chain scission of the i-PP backbone due to the reduced thermal stability of the i-PP on the melt blending. The MFI of the b-PP without the antioxidant was increased due to the chain scission occurred during the melt processing, while on the introduction of the antioxidant, the MFI of the b-PP was decreased. The crystallization temperature of the b-PP was higher than that of PP, which was attributed to the branched chain structure. It was found that the PT was the most effective functional monomers for enhancing the melt properties of the b-PP.

• 폴리머
• /
• 제37권6호
• /
• pp.753-763
• /
• 2013

동종 혹은 이종의 고분자를 레이저로 접착시키는 방법은 레이저 접착이 가지는 장점들로 인해 많은 산업분야에서 광범위하게 사용되고 있다. 산업적으로 많이 사용되는 폴리프로필렌(PP)과 폴리카보네이트(PC)가 레이저 투과용접이 가능하다면 자동차 헤드램프에 큰 이점을 갖고 적용할 수 있을 것이다. 하지만, 폴리프로필렌과 폴리카보네이트는 상용성이 낮아 레이저 접착을 시켜도 강도가 낮은 문제점이 있다. 본 연구에서는 반응압출을 통해 폴리프로필렌을 글리시딜메타크릴레이트(GMA)로 개질하고, 폴리카보네이트와의 상용성, 기계적 물성 및 레이저 투과 용접을 통해 접착성을 조사하였다.

• 한국염색가공학회지
• /
• 제4권4호
• /
• pp.81-89
• /
• 1992

Graft polymers of alginic acid-PMMA, different in composition and Mv of branched PMMA, were prepared by emulsion graft polymerization at various MMA concentrations. In aqueous dispersion solution, the adsorption of graft polymer on the montmorillonite was carried out to modify the surface property of powder, and the adsorption of PMMA in organic solvents (acetone, benzene) on the modified surface of powder were observed. The results obtained were as follows. 1. In emulsion graft polymerization of MMA on the sodium alginate in aqueous solution, SA conversion, MMA conversion and % grafting were increased with increasing MMA concentration where as graft efficiency was decreased. 2. The adsorption amount of graft polymer was increased with the elevation of temperature and the increased of dispersion concentration and with the increase of branched PMMA composition of graft polymer. 3. In organic solvent, the adsorption of PMMA on the surface modified particle was proceeded by the orientation along the stretched branched PMMA of adsorbed graft polymer which is in radial direction to the particle surface. 4. The adsorbed amount of PMMA was increased as the temperature and concentration of PMMA solution, the branching of adsorbed graft polymer and the solvency of solvent were increased.

• Elastomers and Composites
• /
• 제56권1호
• /
• pp.6-11
• /
• 2021

In order to develop an ultra-high-density elastomeric material for substitution of steel dynamic dampers, a new curing system and technique for high-loading of the filler were examined in this study. Mechanochemical modification of chloroprene rubber (MAH-g-CR) using an internal mixer was carried out with maleic anhydride (MAH) as a reactive monomer. The optimum amount of MAH was 10 phr and the efficient grafting of MAH on CR could be achieved at a mixing temperature of 100℃. After preparing MAH-g-CR, 50 mol% epoxidized natural rubber (ENR 50) was blended with MAH-g-CR to develop a "self-curable rubber blend system" via reaction between the functional groups of the elastomeric matrices without the curing agent and additives. The content of ENR 50 was fixed at 30 wt.% throughout evaluation of the curing behavior of the MAH-g-CR/ENR blend. Tungsten powder was added to the MAH-g-CR/ENR matrix up to 60 vol.% to obtain ultra-high-density, and the maximum density obtained was 7.57 g/㎤. Stable ts2 (scorch time) and t90 (90% cure time) could be obtained even when tungsten powder was incorporated up to 60 vol.%. In addition, the tensile strength and damping properties of MAH-g-CR/ENR containing 60 vol.% of tungsten were better than those of CR containing 60 vol.% of tungsten.