• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.200-200
• /
• 2006

Several polynorbornene or poly(norbornene-7-oxide) based functional block copolymers were synthesized by ring opening metathesis polymerization (ROMP) with good molecular weight and polydispersity control. Some representative functional groups in these polymers are a nitrobenzoyl group or ferrocene. These polymers were subjected to various chemical modification reactions to give other block copolymers that contain novel functionality such as amine, diazonium salt, and diazo groups. The resulting polymers were characterized by various techniques such as GPC, NMR, UV-VIS, AFM, and cyclovotammography (CV).

• Macromolecular Research
• /
• v.11 no.3
• /
• pp.202-205
• /
• 2003

The reactive precursors, vinyl ethers, and epoxy-silicones, were synthesized. The vinyl ether monomers were prepared from primary alcohol and ethyl vinyl ether with mercury (II) acetate. The epoxy-functionalized silicones have been achieved by the controlled, rhodium-catalyzed, chemoselective hydrosilation of vinyl ether with siloxanes or silane. It was shown that the hydrosilation proceeds exclusively at the vinyl ether group of alkenyl vinyl ether without participation at the alkenyl group. The photoinduced cationic polymerization of these monomers was studied and found to be all highly reactive.

• Elastomers and Composites
• /
• v.42 no.2
• /
• pp.93-101
• /
• 2007

In this study, for enhancing the durability of permeable pavement material polyurethane(PU) adhesives were developed, and the physical properties upon polymerization and additives were studied. PU polymerization followed the bulk polymerization of free solvent type considering ecological aspect. Additives used in this study were carbon black, calcium carbonate and ultra violet stabilizer. The property changes upon different environment were evaluated with the compressive strength which is the principal measurement of the property of pavement materials. Among polymerized PU, one formulated with esterpolyol and crosslinkable chain extender gave the highest compressive strength of $74.9kgf/cm^2$, better than commercial $60kgf/cm^2$. The strength was the highest when the material specimen contained carbon black and calcium carbonate 20 wt%, respectively. However, UV stabilizer did not show good weathering properties.

• Nuclear Engineering and Technology
• /
• v.47 no.6
• /
• pp.738-745
• /
• 2015

The catalytic exchange of hydrogen isotopes between hydrogen and water has been known to be a very useful process for the separation of tritium from tritiated water. For the process, a highly active hydrophobic catalyst is needed. This study provides an effective fabrication method of size-controlled platinum/poly[styrene-divinylbenzene-tri(propylene glycol) diacrylate] [Pt/poly(SDB-TPGDA)] hydrophobic catalyst beads with a narrow size distribution. Platinum nanoparticles were prepared by ${\gamma}$-ray-induced reduction in the aqueous phase first, and then uniformly dispersed in SDB-TPGDA comonomer after the hydrophobization of platinum nanoparticles with alkylamine stabilizers. The porous Pt/poly(SDB-TPGDA) hydrophobic catalyst beads were synthesized by the UV-initiated polymerization of the mixture droplets prepared in a capillary-based microfluidic system. The size of as-prepared catalyst beads can be controlled in the range of $200-1,000{\mu}m$ by adjusting the flow rate of dispersed and continuous phases, as well as the viscosity of the continuous phase. Sorbitan monooleate and cyclohexanol were used as coporogens to control the porosities of the catalyst beads.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.16 no.3
• /
• pp.29-41
• /
• 1998

The ultraviolet(UV)-curable materials wildly have been used as a ink and coating materials. A according to measure UV polymerization phase separation of acryl groups 2,3,4-functional monomer, a few experiments were performed gel fraction, dynamic viscosity of alkyd resin blend system. Dependence of photoiniator concentration and various monomer, alkyd resin content investigated structural changes of films cured by UV irradiation. Curing rate measured UV irradiation under $25^{\circ}C$, cell gap 7cm and film thickness 100${\mu}{\textrm}{m}$. In results, it was through that the viscoelastic properties of films cured with increasing the ratios of monomer/alkydresin contents are network polymer in properties such as viscoelasticity.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.1024-1027
• /
• 2003

The formation of cholesteric liquid crystal (CLC) film reflecting a broadbanded visible spectrum by application of a liquid crystalline coating followed by UV polymerization (photo-curing) is described. Also, the formation of patterned coatings obtained by a sequence of UV exposure steps is discussed. Such coatings play an important role in the improvement of the performance of liquid crystal displays. In order to make these CLC films, we synthesized new cholesteric liquid crystal molecules (Ch-chol) containing the active reaction site to UV light and investigated to broaden the bandwidth of these cholesteric filters based on the various UV treatments.

• Macromolecular Research
• /
• v.16 no.2
• /
• pp.128-133
• /
• 2008

Several dual-curable acrylic pressure-sensitive adhesives (PSA) were synthesized by the radical polymerization of acrylic monomers containing benzophenone, hydroxyl, and alkyl groups. The optimum extent of UV-induced cure was determined by varying the content of the benzophenone groups (the photoinitiator) from 0.5 to 1.5 wt%. The weight average molecular weight of the polymers obtained ranged from 300,000 to 700,000 amu. The coated pressure-sensitive adhesives were cured either by short UV exposure to induce the grafting of acrylic polymers, or by heating for 6 hat $60^{\circ}C$ to promote the reactions between the polyisocyanates and hydroxyl groups. The dual-curing behavior was determined by monitoring both processes quantitatively by infrared spectroscopy. The developed dual-curable acrylic pressure-sensitive adhesives were found to compensate for the limitations in UV-induced curing of thick coatings.

• Polymer(Korea)
• /
• v.34 no.6
• /
• pp.491-494
• /
• 2010

Colored, electrophoretic polymer nanoparticles of poly (styrene-co-divinylbenzene-co-vinyl acetate)[poly(St-co-DVB-co-VAc)] were prepared by emulsifier-free emulsion co-polymerization and reactive dyeing. The emulsifier-free emulsion polymerization of styrene, divinyl benzene and vinyl acetate was carried out at $70^{\circ}C$ for 20 hrs to obtain monodisperse polymer nanoparticles of poly(St-co-DVB-co-VAc) with an average diameter of 180~200 nm. These nanoparticles were transformed into poly(styrene-co-divinylbenzene-co-vinyl alcohol) [poly(St-co-DVB-co-VA)] nanoparticles through the saponification reaction. The poly(St-co-DVB-co-VA) nanoparticles were treated with reactive dyes to obtain the colored, monodisperse electrophoretic nanoparticles, and their morphology and surface charge were characterized by scanning electron microscopy, differential scanning calorimetry, UV/Vis absorbance and zeta-potentiometry.

• Polymer(Korea)
• /
• v.33 no.5
• /
• pp.452-457
• /
• 2009

Hybrid nanomaterials consisting of multi-walled carbon nanotube(MWNT) and/or PEDOT of conductive polymer were prepared in this study. In the presence of catalyst and ligand, the MWNT-Br compound prepared by the successive surface treatment reaction was mixed with MMA to initiate the atom transfer radical polymerization process. PMMA was covalently linked to the surface of MWNT for the formation of MWNT/PMMA nanocomposites. The EDOT and oxidant were added in the aqueous emulsion of PS produced via a miniemulsion polymerization process and then it proceeded to carry out the oxidative chemical polymerization of EDOT for the preparation of PEDOT/PS nanoparticles with the core-shell structure. The aqueous dispersion of PEDOT:poly(styrene sulfonate) (PSS) was mixed with the silica particles treated with a silane compound and thus PEDOT:PSS-clad silica nanoparticles were prepared by the surface chemistry reaction. The hybrid nanomaterials were analyzed by using TEM, FE-SEM, TGA, EDX, UV, and FT-IR.

• Journal of Adhesion and Interface
• /
• v.5 no.4
• /
• pp.1-8
• /
• 2004

UV-curable pressure sensitive adhesives were prepared by blending acrylic copolymer, copolymerized with butyl acrylate, acrylic acid and methyl methacrylate by solution polymerization, and trimethylolpropane triacrylate. The PSAs were evaluated by adhesion strength with varying UV dose, and also glass transition temperature ($T_g$) of PSAs were measured. When exposed on UV irradiation, the PSAs showed the decreased adhesion strength and increased $T_g$. And following UV irradiation, the PSAs did not leave any residue on wafer after peel off PSA.