• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.320-320
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• 2006

The authors report the synthesis and radical ring-crossover polymerization of macrocycles with radically exchangeable dynamic covalent bonds. The macrocyclic compounds with alkoxyamine units were designed and synthesized by condensation from alkoxyamine-based diol and the corresponding acid chlorides in the presence of pyridine under high-dilution condition. The macrocycles can thermally polymerize by intermolecular radical crossover reaction. Furthermore, the poly(alkoxyamine)s depolymerized to the monomers principally by the intramolecular radical exchange process under high-dilution conditions.

• 공업화학
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• 제31권3호
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• pp.267-276
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• 2020

Oxirane계 단량체의 양이온 개환 공중합반응으로 합성되는 ECH (ephichorohydrin) 기반 copolyol (PECH copolyol)류의 특성에 대한 반응온도, 용매의 종류 및 개시제에 대한 영향을 연구하였다. 공단량체로는 butylene oxide와 hexylene oxide 두 종류의 알킬렌 옥사이드를 사용하였으며, 중합 조건은 methylene chloride (MC) 용매에서 개시제로 diethylene glycol (DEG)를 사용한 조건과 toluene을 용매에서 tripropylene glycol (TPG)를 개시제로 사용한 두 조건으로 진행하였다. 개환 공중합반응에서 active monomer (AM) mechanism 유도를 위해 단량체는 실린지 펌프를 사용해 IMA (increased monomer addition) 방법으로 주입하였고 중합온도는 -5 ℃에서 실행하였다. 합성된 ephichorohydrin (ECH) 기반 copolyol인 PECH copolyol은 치환반응으로 ECH unit를 아지드화하여 glycidyl azide계 에너지 함유 copolyol (GAP copolyol)로 전환하였다. 합성된 아지드화 코폴리올은 용매와 개시제의 변화에 대한 영향은 크지 않았으며, 분자량은 아지드화 반응 후 평균 500 증가함으로써 GAP 코폴리올이 설계한 대로 중합되었음을 확인하였다. DSC 분석으로 copolyol류의 조성비 변화에 따른 유리전이 온도(glass transition temperature, T_g)의 변화를 측정하였을 때, 공단량체의 함량이 증가할수록 알킬 사슬의 길이에 의한 영향으로 T_g와 점도가 모두 감소하는 경향을 보였다. 아지드화 반응과정에서 생성되는 CH₃N₃의 생성을 원천적으로 방지할 수 있으며, 대규모 공정이 가능할 것으로 기대된다.

• 한국세라믹학회지
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• 제55권2호
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• pp.126-134
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• 2018

Using aqueous solution free radical polymerization with glacial acrylic acid (GAA), maleic anhydride (MA) and sodium methallyl disulfonate (SMADS), a novel linear polycarboxylate dispersant was synthesized for ceramics. Dispersant linear structural characterization was done by FTIR, $^1H$ NMR, HPLC and GPC, and the ratio of monomers was determined using an orthogonal experiment. This research is focused on the effects of polymerization temperature, monomer mole ratios and dosage of initiator on ceramic slurry viscosity with linear polycarboxylate dispersant for ceramic dosage rate of 0.30% (based on dry slurry), all of which were investigated by single factor test. The best polymerization conditions for linear GAA-MA-SMADS are when n(AA) : n(MA) : n(SMADS) equals 3.0 : 1.0 : 0.5, the molecular weight of the polymer is 4600 daltons, the initiator sodium persulfate accounts for 7% of the total mass of polymerized monomers, the polymerization temperature is $90^{\circ}C$ and the reaction time is 2 h. The ceramic body slurry viscosity drops from $820mPa{\cdot}s$ to $46mPa{\cdot}s$ when the concentration of the polycarboxylate dispersant is 0.30%.

• 대한화학회지
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• 제21권2호
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• pp.132-138
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• 1977

$SO_2$/KOH 촉매에 의한 ${\varepsilon}$-caprolactam의 음이온 중합을 시도하였으며 얻어진 중합체의 percent conversion 및 중합에 미치는 여러 요인을 조사하였고 중합체의 물리적 성질 및 반응속도에 대하여 고찰하였다. $SO_2$/KOH 촉매에 의하여 얻은 중합체는 hydrolytic polymerization에 의하여 제조된 nylon 6 보다 저온에서 중합이 가능하며 고유점도 및 융점이 더 높은 것으로 보아 중합도도 높으며 중합체의 분자 배열이 더 규칙적으로 배열되어 있다는 것을 추리할 수 있었다.

• Macromolecular Research
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• 제16권2호
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• pp.155-162
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• 2008

We report the successful synthesis of poly(NBECOOH-b-NBEPOSS) copolymers, taking advantage of the sequential, living ring opening metathesis polymerization of NBETMS and NBEPOSS using the $RuCl_2(=CHPh)(PCY_3)_2$/$CH_2Cl_2$/$20^{\circ}C$ system, followed by the hydrolysis of trimethylsilyl groups in poly(NBETMS-b-NBEPOSS) copolymers. The living behavior of ROMP of NBETMS was first investigated using two diagnostic plots, a first order kinetic plot and a $\bar{M}_n$ vs. conversion plot. The plots confirmed that no termination and chain transfer reaction had occurred during polymerization. Poly(NBECOOH-b-NBEPOSS) copolymers were prepared using the sequential monomer addition of NBEPOSS to living poly(NBETMS) chain ends, followed by the hydrolysis of trimethylsilyl groups in the poly(NBETMS-b-NBEPOSS) copolymers. The high structural integrity of poly(NBE-COOH-b-NBEPOSS) copolymers was confirmed by $^1H$-NMR, $^{13}C$-NMR spcctroscopy and GPC.

• 대한화학회지
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• 제25권4호
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• pp.214-218
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• 1981

Solid인 Hexogen 존재하에서 hydroxyl-terminated polybutadiene과 isophorone diisocyanate의 혼성중합반응속도에 관하여 연구하였다. 중합반응속도는 Hexogen의 첨가량이 증가할 수록 빠르게 나타났지만, Hexogen의 촉매적 역할은 없었으며, 오직 entropy control에 의한 반응임을 밝혔다. 이 반응은 2차 반응속도법칙에 잘 일치하며, activation energy는 8.4 Kcal/mole로 거의 일정하다.

• 한국의류산업학회지
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• 제6권3호
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• pp.384-392
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• 2004

The purpose of this study is in development of effective filter-type polymer adsorbent for removal of pollutants from wastewater by UV irradiation graft polymerization. Photografting of acrylic acid (AA) on polypropylene (PP) nonwoven fabric using benzophenone (BP) as a photosensitizer was investigated. Inhibition of homopolymerization was achieved by adding various concentrations of $FeSO_4{\cdot}7H_2O$, $CuSO_4{\cdot}5H_2O$ and Mohr's salt. As AA concentration was increased, the degree of grafting was increased as to a specific value and then decreased, and the effect of BP concentration showed the same tendency. It was also found that the degree of grafting increased with reaction time and reaction temperature. Addition of the polyfunctional monomers and $H_2SO_4$ to the grafting system accelerated the photografting. The melting temperature, molecular weight and breaking stress and breaking strain were decreased with the increase in the degree of grafting.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.418-418
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• 2012

We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.

• 산업기술연구
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• 제25권A호
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• pp.141-149
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• 2005

We investigated numerically the evolutions of several chemical species which are important for film growth and particle generation in the pulsed $SiH_4$ plasmas. During the plasma-on, the $SiH_x$ concentration increases with time mainly by the generation reaction from $SiH_4$, but, during the plasma-off, decreases because of the hydrogen adsorption reaction. During the plasma-on, the concentrations of negative ions increase with time by the polymerization reactions of negative ions and those become almost zero in the sheath regions because of the electrostatic repulsion. During the plasma-off, the concentrations of negative ions decrease with time by the neutralization reactions with positive ions and some negative ions can diffuse toward the sheath regions because there is no electric field inside the reactor. The polymerized negative ions of higher mass can be reduced successfully by using the pulsed plasma process.

• 한국염색가공학회지
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• 제15권3호
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• pp.154-160
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• 2003

Polypropylene nonwoven fabrics were grafted with acrylic acid by a preirradiation method by using electron beam accelerator. The effect of irradiation dose, storage time, concentration of acrylic acid, reaction temperature, reaction time and Mohr's salt concentration on the degree of grafting were investigated in detail. The grafted Polypropylene nonwoven fabrics were characterized using IR spectroscopy and SEM. The results showed that the degree of grafting increased with increasing absorbed dose and the Mohr's salt in the acrylic acid solution promoted grafting efficiency.