• 접착 및 계면
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• 제13권2호
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• pp.64-72
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• 2012

비닐아세테이트와 알킬아크릴레이트계 에멀젼공중합에서 개시제인 ammonium persulfate (APS)의 농도, 보호 콜로이드인 poly(vinyl alcohol) (PVA)의 종류와 농도, 공단량체인 methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (BA)의 혼합비를 변화시켜 중합하였다. 제조된 poly(vinyl acetate-co-methyl acrylate) (PVAc/PMA), poly(vinyl acetate-co-ethyl acrylate) (PVAc/PEA), poly(vinyl acetate-co-n-butyl acrylate) (PVAc/PBA)에 대하여 다음과 같은 결론을 얻었다. 등온 열분해법으로 $100{\sim}200^{\circ}C$ 영역에서 구한 비닐아세테이트와 알킬아크릴레이트 공중합체에 대한 등온 열분해 활성화에너지는 PVAc/PMA > PVAc/PEA > PVAc/PBA이었으며, 플라스마 처리 전과 후의 접착박리강도는 PVAc/PMA > PVAc/PEA > PVAc/PBA의 순이었다.

• 폴리머
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• 제33권3호
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• pp.230-236
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• 2009

비닐 아세테이트/알킬메타크릴레이트계 에멀젼 공중합에서 반응온도, 개시제의 종류와 농도, 보호콜로이드인 PVA의 종류와 농도, 공단량체인 MMA, EMA의 조성비를 변화시키며 중합하였다. 제조된 공중합체인 poly(vinyl acetate-co-methyl methacrylate)(PVAc/PMMA), poly(vinyl acetate-co-ethyl methacrylate)(PVAc/PEMA)를 수분 측정기를 사용하여 100, 130, 150, 180, $200^{\circ}C$에서 등온건조 시키고, 그 건조 특성을 고찰하여 다음과 같은 결론을 얻었다. 등온법으로 얻은 중합체 고형화 과정의 활성화 에너지는 PVAc/PMMA> PVAc/PEMA> PVAc의 순으로 공단량체의 곁사슬의 탄소수 증가에 따라 감소하였다. 접착박리강도는 동일한 조성의 공중합체에서 보호콜로이드 함량에 비례하여 증가하였고, 내수 접착박리강도는 최적의 보호콜로이드 함량에서 공단량체의 종류와 함량에 따라 PVAc/PMMA>PVAc/PEMA>PVAc 순이다.

• Macromolecular Research
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• 제17권5호
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• pp.307-312
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• 2009

Core-shell hydrogel nanocomposite was fabricated by encapsulating a silica-gold nanoshell (SGNS) with poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-co-AAc) copolymer. The oleylamine-functionalized SONS was used as a nanotemplate for the shell-layer growth of hydrogel copolymer. APS (ammonium persulfate) was used as a polymerization initiator to produce a hydrogel-encapsulated SGNS (H-SGNS). The amounts of NIPAM (N-isopropylacrylamide) monomers were optimized to reproduce the hydrogel-encapsulated SGNS. The shell-layer thickness was increased with the increase of polymerization time and no further increase in the shell-layer thickness was clearly observed over 16 h. H-SGNS exhibited the systematic changes of particle size corresponding to the variation of pH and temperature, which was originated from hydrogen-bonding interaction between PNIPAM amide groups and water, as well as electrostatic forces attributed by the ionization of carboxylic groups in acrylic acid.

• 한국환경과학회지
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• 제15권12호
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• pp.1155-1161
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• 2006

The characteristics of photocatalytic degradation of tar colorants such as brilliant blue FCF(BBF) and tartrazine(TTZ) with zinc oxide suspension was studied in a batch reactor under irradiation of ultra-violet ray. Photocatalytic degradation of TTZ with ZnO was more higher than that of BBF, and was Increased with dosage of ZnO below 5g, but was nearly affected with initial pH of two tar colorants aqueous solution. Ammonium persulfate was more effective oxidant than potassium bromate which slightly increased the degradation of BBF, but not increased the degradation of TTZ. The photocatalytic degradation rates of BBF and TTZ were pseudo-first order with rate constants of 0.0066, 0.0092 and $0.015min^{-1}$ for BBF, 0.042, 0.017 and $0.110min^{-1}$ for TTZ at the dosage of 1, 2 and 5g ZnO, respectively.

• Bulletin of the Korean Chemical Society
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• 제23권2호
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• pp.325-329
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• 2002

In this study, the dependency of the behavior of propagating front on the reaction condition in frontal polymerization reaction has been studied. We have used some multifunctional acrylates as a monomer and ammonium persulfate as an initiator for the polymerization reactions. In frontal polymerization, a method of producing polymeric materials via a thermal front that propagates through the unreacted monomer/initiator solution, the behavior of self propagating front shows various dynamic patterns depending on the reaction condition. We have obtained some spin modes of propagating front in the number of 'hot spots' or 'spin heads' by changing the reaction condition. The effect of the reactor tube diameter on the mode of propagating front has also been studied by using some reactor tubes with different size of tube diameter and it has been examined in some detail by adopting an experimental method of two-tubes system.

• 한국염색가공학회지
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• 제5권3호
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• pp.173-181
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• 1993

Dyeing cotton fabric with direct dye (C. I. Direct Blue 15) by redox sytem of ammonium persulfate as an oxidant and glucose as reductant was studied. It was found that covalent bond between dye and cellulose molecule can be formed by free radical produced by the redox system in the dye bath, which enhanced significantly the color strength. The retained color strength after DMF extraction was much better in the presence than in the absence of the redox sytem. The optimum dyeing condition was 0.028 mol/$\ell$(APS/Glucose each) of redox concentration, 65$^{\circle}C$ of dyeing temperature and 60min of dyeing time. The color variation on the dyed sample had not been observed as a result of fixed ${\lambda}_max$.

• Advances in materials Research
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• 제3권2호
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• pp.117-128
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• 2014

Processable conducting polyaniline derivative with free amine functional groups was successfully synthesized from the monomer o-phenylenediamine in aqueous hydrochloric acid medium using ammonium persulfate as an oxidative initiator. The synthesized poly(o-phenylenediamine) (PoPD) in critical condition was found to be completely soluble in common organic solvents like dimethyl sulfoxide, N,N-dimethyl formamide etc. From the intrinsic viscosity measurement, the optimum condition for the polymerization was established. The polymer was characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy ($^1HNMR$) and thermogravimetric (TGA) analyses. The weight average molecular weights of the synthesized polymers were determined by the dynamic light scattering (DLS) method. From the spectroscopic analysis the structure was found to resemble that of polyaniline derivative with free amine functional groups attached to ortho/meta position in the phenyl ring. However, very little ladder unit was also present with in the polymer chain. The moderate thermal stability of the synthesized polymer could be found from the TGA analysis. The average DC conductivity of $2.8{\times}10^{-4}S/cm$ was observed for the synthesized polymer pellet after doping with hydrochloric acid.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.178-179
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• 2006

나노 크기를 가지는 DNA 분자를 template로 사용하여 전도성 고분자의 일종인 polypyrrole nanowire를 합성하였다. 본 논문에서 합성된 polypyrrole nanowire는 단량체인 pyrrole과 산화제와의 화학적인 반응에 의해 만들어졌다. 먼저 DNA 분자를 APTES(3-aminopropyltriethoxysilane) modified Si surface 위에 정렬한다. 그리고 이 기판을 농도를 달리한 pyrrole solution에서 incubationn한다. 마지막으로 APS (ammonium persulfate)와 반응시켜 conductive nanowire를 합성하였다. SEM을 이용하여 silicon 기판위에 1차원적으로 정렬된 나노 크기를 가지는 polypyrrole nanowire를 관찰할수 있었다. 그리고 pyrrole의 농도에 따라 nanowire의 uniformity를 조절할 수 있었다.

• 접착 및 계면
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• 제7권4호
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• pp.45-52
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• 2006

Five low molar ratio urea-formaldehyde (LUF) resins were synthesized in this study. The effects of molar ratio, free formaldehyde content, and catalysts on the curing characteristics of LUF resins were studied by measuring its free formaldehyde content, pH value change after catalysts added, curing rate, and pot life, observing its cured appearance, and analyzing its thermal behavior. The results indicate that: 1) The LUF resin with lower molar ratio than 1.0 can still cure; 2) Free formaldehyde content is not the main factor in affecting curing rate of LUF resin; 3) Compared with ammonium chloride as a traditional catalyst, persulfate salts markedly accelerate the curing rate of LUF resin, and result in the different appearance; 4) the addition of sodium chloride to catalysts can accelerate the curing rate of LUF resin, but the effect is moderate.

• 한국환경과학회지
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• 제13권6호
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• pp.599-603
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• 2004

In a batch reactor, the characteristics of photocatalytic degradation of brilliant blue FCF in titanium dioxide suspension was studied under the irradiation of ultra-violet ray. Photocatalytic degradation in anatase type of TiO$_2$ was more effective than in rutile type of $TiO_2$ below the dosage of 5g. The degradation rate was slightly increased with decreasing initial pH of brilliant blue FCF aqueous solution, but rapidly increased with the addition of oxidant. Potassium bromate acted as more effective oxidant than ammonium persulfate. The photocatalytic degradation rate of brilliant blue FCF was pseudo-first order with rate constants of 0.012, 0.006 and $0.003min^{-1}$ at initial pH 3.1, 5.2 and 7.1 of brilliant blue FCF solution, respectively.