• Polymer(Korea)
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• v.34 no.2
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• pp.159-165
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• 2010

Dipyridine-terminated polystyrenes and polybutadienes were synthesized by the chain endfunctionalization reaction of polystyryllithium (PSLi) and polybutadienyllithium (PBDLi) with di(2-pyridyl) ketone(DPK) using a living anionic polymerization method in the Ar-glove box. Living polymeric lithiums with low molecular weights (Mw=1000~2000 g/mol) were used to investigate the chain end-functionalization yield with DPK and the degree of coupling reaction by the attack of organolithium to the pyridine ring in the presence of TMEDA using GPC, $^1H$-NMR, $^{13}C$ analysis. DPK-terminated PBD exhibited much higher functionalization yield and less amount of coupling reaction compared with DPK-terminated PS. 86% functionalization yield with 9% degree of coupling was obtained when the PBDLi was added dropwise to DPK solution at room temperature. The functionalization yield was increased as the reaction temperature decreased, however, no LiCl effect was observed in this chain end-functionalization reaction with DPK.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.296-309
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• 1999

Autopolymerized resin facilitates a more rapid and easier means for the construction of removable orthodontic appliances than heat cured resin. But many reports reveal that more unreacted monomer is found in autopolymerized resin. It is very important to achieve maximum degree of polymerization because if polymerization is inadequate, high level of unreacted monomer has been shown to adversely affect mechanical and physical properties, and also the question of allergy or toxicity to methylmethacrylate must be considered. The purpose of this study was to compare the degree of polymerization according to curing method and curing time. Five groups were desinged ; Group 1 was polymerizied at room temperature($28^{\circ}C$) ; Group 2 in $28^{\circ}C$ water ; Group 3 in $28^{\circ}C$ water under 30psi pressure ; Group 4 in $43^{\circ}C$ water ; Group 5 in $43^{\circ}C$ water under 30psi pressure for 10 minutes, 1 hour 12 hours, 1 day and 3 days. The degree of polymerization was measured by means of Fourier Transform Infrared spectroscopy. The results were as follows: 1. The degree of polymerization increased constantly in accordance with curing time in all groups and after curing for 10 minutes, Group 1 showed significantly higher degree of polymerization after 12 hours and Group 2, Group 3, Group 4, Group 5 after 1 hour(p<0.05). 2. The degree of polymerization decreased in the order of Group 5, Group 4, Group 3, Group 2, Group 1 except when the curing time was 1 hour and 12 hours(p<0.05). 3. The degree of polymerization of Group 4, Group 5 cured at $43^{\circ}C$ showed significantly higher degree of polymerization than Group 2, Group 3 at $28^{\circ}C$ except when the curing time was 1 day(p<0.05). 4. Among Group 2, Group 3 and Group 4, Group 5, the pressure had no effect on polymerization except when the curing time was 12 hours(p<0.05). 5. Between Group 1 and Group 2, the method of storage had no effect on polymerization except when the curing time was 1 hour(p<0.05).

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.26-26
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• 2012

The hydrophobic nature of the wool surface give rise to difficult penetration of dye molecules. Among all the methods of modification, graft polymerization is an attractive method to impart a variety of functional groups to a polymer. Grafting has been made by irradiating the light on the polymer in the presence of a solvent containing monomer. The energy source commonly used are high-energy electrons, X-rays, UV and visible light. UV irradiation is a relatively low-energy radiation in comparison with others since it has the least possibility to change bulk properties. In the present paper, a photo-reactive dye was synthesized from quinizarin by the reaction with methacryloyl chloride. The synthesized dye was continuously grafted onto wool fabric at room temperature by UV irradiation. Several key parameters including UV energy, dye concentration and pH have been examined to understand their influence on the photoreactive coloration.

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.75-87
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• 1994

The metal complexes containing amino acidic ligands were prepared by using 11 kinds of amino acids as ligands and Ni, Cu, Co, Zn, Fe as a central metal. The starting was continued for 4hrs at room temperature. But Bis(D,L-Serine)Ni (II), and (D,L-Serine)Co (II) were prepared by heating method($80^{\circ}C$). In order to investigated reaction activity of Bis(D,L-Aspartato) Metal(II), stirring time was varied and Bis(D,L-Tyrosine ) Metal(II) used different divalent metal salts. We anticipate getting a great value from these prepared complexes as a monomer and a catalyst of polymerization which has peculier characteristics.

• Textile Coloration and Finishing
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• v.8 no.4
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• pp.11-18
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• 1996

Natural functional compound in the textile finishing for health and amenity using fragrant material have been applied by microencapsulation method. The microcapsules containing fragrant materials as functional compound were produced by in situ polymerization using urea-formaldehyde prepolymer. The average diameter of microcapsules is 2.75$\mu$ and particle size ranges over 0.5~10$\mu$. Fragment material is extracted approximatly proportioned from microcapsule at room temperature. The adsorption of microcapsule was improved by pretreatment of cationic agent. Fragrant materials in microcapsule was revealed to have long release time.

• Elastomers and Composites
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• v.51 no.2
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• pp.99-105
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• 2016

Alkoxy modified silicone (PAMS) was synthesized from hydroxyl-terminated polydimethylsiloxane (OH-PDMS) and vinyltrimethoxysilane (VTMO) under alkali catalyst (NaOH and KOH) at room temperature ($25^{\circ}C$) via condensation polymerization. Then, the structural verification of the synthesized PAMS was confirmed using $^1H$-NMR and FT-IR spectroscopy. The reaction rate of PAMSs was studied in terms of the concentration variation of alkali catalyst. The reaction rate increased with the concentration of alkali catalyst, but no correlation between conversion and concentration of alkali catalyst was observed.

• Journal of the Korean Applied Science and Technology
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• v.24 no.1
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• pp.23-30
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• 2007

Kevlar was chemically surface modified with resorcinol-formaldehyde(RF) prepolymer and VP rubber latex for application to high strength tirecords. RF prepolymer was easily obtained by polymerization at room temperature in the presence of a base catalyst. The mechanical and thermal properties of Kevlar were not significantly changed during surface treated under various conditions. The change of adhesion with rubber were investigated through H-test method. Maximum increase of adhesion force between rubber and Kevlar was obtained up to 40% than that of untreated one when the fiber was soaked in RFL dipping solution and thermally treated at $170^{\circ}C$ for 3 - 5min.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.310-313
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• 2000

Polyaniline Emeraldine Base (PANI EB) polymerized by chemical oxidative polymerization was doped with Camphorsulfonic Acid(CSA). Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) solutions were solved in organic solvents and sonificated at the room temperature for different solvents in PANI-CSA ES solution and sonification time. PANI-CSA ES solutions was coated on PET films using bar coater. 1-Step oxidatively-polymerized Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) was solved in m-cresol:chloroform 1:1 co-solvents and their solution was bar-coated on PET film. The surface resistivities of these coated films were measured, The surface resistivity of PANI-CSA ES solution in m-cresol:chloroform 1:1 co-solvent system was 5${\times}$10$^2$$\Omega$/$\square$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.544-547
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• 2000

Polypyrrole (PPy) was chemically synthesized within the pores of nanoporous polycarbonate (PC) Particle Track-etched Membranes (nano-PTM). Hollow tubules are formed because polypyrrole initially deposits on the surface of the pores walls. By running successive syntheses, we have obtained wires (filled tubules). The redox property of PPy nanotubules was investigated by cyclic voltammetry. The redox potential was lowered as much as 0.5V vs. Ag/AgC1, comparing with electrosynthesized PPy film. It suggests that an electron hopping mechanism of PPy nanotubules was improved. Electric conductivity of PPy nanotubules and nanowire was evaluated. We obtained good electric conductivity of PPy nanotubules even in the neutral state. The conductivity and activation energy were $10^1$ order at the room temperature and 25.3 meV respectively.

• Journal of the Korean Applied Science and Technology
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• v.16 no.2
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• pp.171-177
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• 1999

The objectives of this study is to investigate the optimum reaction conditions and to identify the product formula in the synthesis of a silicone/acrylic resin that curing in moisture at room temperature. By the addition polymerization of monomers, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and 3-methacryloxypropyltrimethoxysilane. a quarter polymer was obtained. Among various initiators investigated in this study, 2.2'-azobisisobutyronitrille was found to be the most suitable initiator. The optimum reaction conditions found in this study are 70 wt% of initial solvent amount, 120 minutes of dropping time, 3 times of initiator addition, $82{\sim}105^{\circ}C$ of reaction temperature, and 8 hrs of reaction time. Also, number average molecular weight of $11700{\sim}33100$ and molecular weight distribution of $1.81{\sim}3.44$ were obtained.