• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.05a
• /
• pp.221-226
• /
• 2008

Novel synthetic routes were proposed for hydroxy-terminated Poly(EO-co-THF) by Cationic ring-opening copolymerization of Tetrahydrofuran(THF) and Ethylene oxide(EO). It was carried out using Boron trfluoride tetrahydrofuranate($BF_3$ THF complex) as catalyst in the presence of 1,4-butandiol. The resultant products are well-defined linear polyetherpolyol. Polyurethane(TPU) were prepared using resultant polyetherpolyol with IPDI/N-100 as curing agent and TPB(Triphenylbismuth) /MA(Maleic anhydride) mixture as cure catalyst. Mechanical properties of TPU prepared from poly(EO-co-THF) polyol were investigated and compared with polyurethane using ATK HTPE.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.7
• /
• pp.1521-1525
• /
• 2009

Thermosensitive block copolymers of ethylene oxide and N-isopropylacrylamide (NIPAM) were synthesized. A five armed star shape oligo(ethylene oxide) initiator with a cyclotriphosphazene core was prepared and used for the atom transfer radical polymerization (ATRP) of NIPAM. The lower critical solution temperatures (LCSTs) of the copolymers were 36 to 46 ${^{\circ}C}$, higher than that of PNIPAM (32 ${^{\circ}C}$), depending on their molecular weights. The copolymers were soluble in water below the LCSTs but formed micelles above the LCSTs. The thermosensitive micellization behaviors of the polymers were investigated by fluorescence spectroscopy. With increasing the temperature of an aqueous solution of P2 and pyrene above the LCST, the peak of 333 nm red-shifted to appear around 339 nm and its intensity increased significantly, indicating the micelle formation. The transfer of pyrene into the micelles was also confirmed by a confocal laser scanning microscope. The fluorescence image obtained from P2 in an aqueous pyrene solution exhibited a green emission resulting from the pyrene transferred into the micelles. Salt effects on the solubility of the copolymers in an aqueous solution were investigated. The LCST of P2 decreased sharply as the concentration of sodium chloride increased, while decreased slowly with potassium chloride.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1997.10a
• /
• pp.173-179
• /
• 1997

출발원료로 ferric nitrate, ethylene glycol, acethyl acetone 혼합용액을 사용하여 dip-coating된 $\alpha$-Fe$_2$O$_3$막을 제조하였다. coating을 위한 혼합용액의 시간의 경과에 따른 용액내의 가교(polymerization) 효과를 관찰하기 위해서 적외선 분광기(FT-IR)을 사용하였고, 막 형성 시 유기물 분해 및 결정화 시작 온도를 확인하기 위하여 FT-IR, XRD, DSC 등을 이용하여 분석을 행하였다. 또한 각 조건에서 제조된 막은 X-선 회절 분석을 통해 결정상을 확인 하였으며, SEM을 통하여 막의 두께 변화에 대하여 관찰하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.578-580
• /
• 2003

PEDOT [poly(3,4-ethylenedioxythiophene)] powder soluble in common organic solvent were synthesized by oxidative polymerization of EDOT (3,4-ethylene dioxythiophene) monomer using functional dopant, DEHSNa [sodium di(2-ethylhexyl)sulfosuccinate]. Transparent electrodes were made by spin casting of PEDOT/organic solvents on substrates. The electrode showed the transmittance < 90% in visible region and the surface resistance of> ${\sim}10^3\;ohm/{\square}$, respectively.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2008.10a
• /
• pp.9-10
• /
• 2008

Tricrecyl phosphate(TCP)-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and Ethylene diamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation.

• Polymer(Korea)
• /
• v.39 no.1
• /
• pp.169-173
• /
• 2015

Metallocene was supported on the silica, which was functionalized with aminosilanes such as aminopropyltrimethoxysilane (1NS) or N-[3-(trimethoxysilyl)propyl]ethylenediamine (2NS), and ionic liquids such as 1-butyl-4-methylpyridinium chloride (Cl), tributylmethylammonium chloride (Amm), benzyldimethyltetradecylammonium chloride (Ben), 1-butyl-1-methylpyrrolidinium chloride (Pyr), and then ethylene polymerizations were performed. The Zr contents of $SiO_2/1NS/IL/(n-BuCp)_2ZrCl_2$ and $SiO_2/2NS/IL/(n-BuCp)_2ZrCl_2$ were lower than those of only aminosilane-treated silicas. However, the polymerization activity of $SiO_2/1NS/IL/(n-BuCp)_2ZrCl_2$ was higher than that of $SiO_2/1NS/(n-BuCp)_2ZrCl_2$. The polymerization activity of $SiO_2/2NS/IL/(n-BuCp)_2ZrCl_2$ was lower than that of $SiO_2/2NS/(n-BuCp)_2ZrCl_2$ due to much lower Zr content.

• Polymer(Korea)
• /
• v.31 no.1
• /
• pp.80-85
• /
• 2007

Maleic anhydride (MA) modified ethylene-propylene-diene terpolymer (MEPDM) was pre-pared from solution polymerization. MEPDM-g-PST copolymer was prepared by melt polymerization of male ate d EPDM and quaternary ammonium silyl polydimethylsiloxane -7,7,8,8- tetracyanoquinodimethane (TCNQ) adduct (PST) in internal mixer and MEPDM-g-PST/HDPE/CB (MPEC) was prepared by com-pounding HDPE, MEPDM-g-PST copolymer and carbon black (CB, 5, 10, 15, and 20 phr), and HDPE/ CB (PEC) by compounding HDPE and CB (5, 10, 15, and 20 phr), respectively. The structure of MEPDM-g-PST copolymer was confirmed by measuring the FTIR. The maximum grafting ratio of MA onto EPDM was 2.35%. The thermal and mechanical properties of the composites were measured and dispersion characteristics of CB in matrix show that CB in MPEC was better dispersed than that in PEC composite.

• Macromolecular Research
• /
• v.8 no.5
• /
• pp.238-242
• /
• 2000

The new trisiloxane-bridged heterometallic dinuclear metallocenes, hexamethyltrisiloxanediyl(cyclopentadienyltitanium trichloride) (cyclopentadienylindenyl zirconium dichloride) , $C_3ITi-Cp(CH_3)_2Si-O-Si(CH_3)_2-O-Si(CH_3)_2-Cp-ZrIndCI_2$ (1) and hexamethyltrisiloxanediyl (cyclopentadienylindenylhafnium dichloride) (cyclopentadienylindenyl zirconium dichloride), $C_2IndHf-Cp(CH_3)_2Si-O-Si(CH_3)_2-Cp-ZrIndCl_2$ 2) connecting two dissimilar metallocenes were synthesized and used for ethylene polymerization in the presence of modified methylaluminoxane (MMAO) cocatalyst. The catalytic activity of heterometallic dinuclear metallocenes, 1 and 2 was lower than that of corresponding mononuclear metal-locene as well as two physically mixed catalysts, $CpTiCl_2/Cp_2ZrCl_2 and Cp_2HfCl_2/Cp_2ZrCl_2$. On the tither hand, MWD of PE obtained with 1 and 2 was remarkably broader ($M_w/M_n$) became up to 9.4) than those of PEs prepared with the corresponding mononuclear metallocenes and mixed catalysts. With analysis by GPC and CFC, it was found that PE produced by the heterometallic dinuclear metallocenes exhibited the definite bimodal GPC curves that should cause the broadening of MWD.

• Polymer(Korea)
• /
• v.31 no.5
• /
• pp.410-416
• /
• 2007

Monodisperse polymer particles were prepared via one- step seeded polymerization using PMMA as seed particles, and HDDA, triEGDMA or EGDMA as crosslinking monomer. For the study, the effects of 1) the ratio of the absorbed monomer to the seed polymer particles (swelling ratio), 2) the characteristics of crosslinking monomer, 3) electroless Ni plating, and 4) electroless Au Plating on the variation of mechanical properties of polymer particles, such as recovery rate, K-values, breaking strength and breaking displacement were investigated by using MCT (micro compression test). It was observed that swelling ratio of polymer particles influenced only on breaking strength of polymer Particles, while electroless plating did on recovery rate, K-values ($K_{10}\;and\;K_{20}$) and breaking strength of electroless plated polymer particles. However, breaking displacement and K-values ($K_{30}{\sim}K_{50}$) were more or less insensitive to electroless plating.

• Journal of the Korean Chemical Society
• /
• v.51 no.6
• /
• pp.499-505
• /
• 2007

Monomeric complexes of nickel(II) having terdentate bis(imino)aryl ligands (N,C,N-pincer) are reported. New complexes (2,6-(ArN=CH)2C6H3)NiBr (Ar=2,6-dimethylphenyl (1), 2,6-diisopropylphenyl (2)) have been synthesized through oxidative addition of 1,3-(ArN=CH)2C6H3Br (bis(N-Ar)-2-bromoisophthalaldimine: Ar=Ph-2,6-Me2, Ph-2,6-iPr2) to Ni(COD)2 (COD=1,5-cyclooctadiene), in high yields. The development of a synthetic route to ligands and nickel complexes is outlined. The complexes were characterized by IR, 1H-NMR and elemental analysis. Full characterization of complexes 1 and 2 is discussed. An investigation into the catalytic activity of the complexes in ethylene polymerization was performed, resulting in no formation of polyethylenes but producing a small amount of oily oligomers. Preliminary results indicate that the pincer complexes were found to be inactive as catalysts in ethylene polymerization.