• Journal of the Korean Chemical Society
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• v.19 no.5
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• pp.367-374
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• 1975

Glycine residue in N-X-glycylphenylalanine methyl ester(X = trifluoroacetyl or acetyl) was converted into aspartic acid derivative by a photoalkylation reaction. The reaction was induced with 350 nm lamp using a combination of diacetyl/di-t-butyl peroxide (DBP) as the photoinitiator, and acetic anhydride as the alkylating agent. In the thermal reaction with DBP and acetic anhydride, the same alkylation reaction of the dipeptide was observed. From this thermal alkylation reaction the photoalkylation reaction is also thought to undergo via free radical mechanism.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.1-2
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• 2003

Some new synthetic routes for the preparation of poly (isobutyl vinyl ether) (P(IBVE)) having a controllable molar mass with narrow distribution via catalytic or photoinduced living cationic polymerization and their conversion to corresponding PVA have been developed. It was found that the combination of iodomethyl methyl ether (IMME)-zinc iodide is effective in the initiation of the catalytic and the various combinations of diphenyliodonium halides, well known photocationic initiators (DPIX) with zinc halides (ZnX$_2$) are also useful in photoinduced living cationic polymerization of isobutyl vinyl ether (IBVE). Polymerization both in the catalytic and photoinduced systems precede until the full consumption of the monomer and the rate of polymerization increases as the concentration of the catalyst or photoinitiator. The number average molar mass of the resulting polymer is proportional with % conversion, which is determined by the ratio of monomer consumed and the initial values of the catalyst or initiator. The living nature was also confirmed by subsequent monomer addition technique.

• Macromolecular Research
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• v.11 no.6
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• pp.495-500
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• 2003

UV-induced graft polymerization of glycidyl methacrylate (GMA) to a polypropylene (PP) membrane was carried out in the vapor phase with benzophenone (BP) as a photoinitiator. Attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to characterize the copolymer. The degree of grafting increased with increasing reaction time, increased UV irradiation source intensity, and increased immersion concentration of the BP solution. The optimum synthetic condition for the PP-g-GMA membrane was obtained with a reaction time of 2 hrs, a UV irradiation source intensity of 450 W, and an immersion concentration of the BP solution of 0.5 mol/L. The pure water flux decreased upon increasing the degree of grafting and increasing the amount of diethylamino functional group introduced. The analysis of AFM and SEM images shows that the graft chains and diethylamino groups of PP-g-GMA grew on the PP membrane surface, resulting in a change in surface morphology.

• Textile Coloration and Finishing
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• v.20 no.5
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• pp.28-34
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• 2008

PET fabrics were photografted under continuous UV irradiation with vinyl pyrrolidone (VP) and acryloylmorpholine(ACMO) as monomers and benzophenone as a hydrogen-abstractable photoinitiator. ACMO can be grafted onto the PET fabrics more efficiently than VP. The grafted PET surfaces were characterized by ATR, ESCA, SEM and zeta potential measurement. ATR and ESCA analysis indicated significant alterations on chemical structure and atomic composition on the surface of the grafted fabrics, where nitrogen content increased with increasing grafting yield. SEM images showed that the fabric surface was covered with the grafted polymers. The zeta potentials and the water wettability of the grafted PET increased with grafting. Also the photografted fabrics showed an increased dyeablity to reactive dyes and increased affinity to various iodine species which imparted anti-bacterial properties.

• Journal of the Korean Graphic Arts Communication Society
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• v.12 no.1
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• pp.81.2-98
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• 1994

This syudy analyzed the main bodies, marginal space, Position of the main bodies of current textbooks in high schools and "the eriteria of reading system for textbooks" which was suggested the Department of Education and Provided some suggestions for the improvement. The research methods used for the study were both literature review and survey rdsdarch with a questionaire. Inorder to research for the main body of textbook, space of margin, the optimum position of the main body, sizes of litters, spaces between letters, words, lines, length of lines, sizes of main body and margin, and margin and position of main body were checked through a related literature review. For the questionaire experiment, a questionaire based on data drawn from analysis of current textbooks, :criteria for reading system of textbook" suggested by the Department of Education, and some suggestions for improvement by the researcher was made and used for the test, targetting 384 body and girl student in high schools.n high schools.

• Macromolecular Research
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• v.15 no.6
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• pp.560-564
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• 2007

The photostabilization and cure kinetics of UV-curable, optical resins containing various formulations of photostabilizers were investigated to determine the system with the highest cure conversion and durability. Photo-DSC analysis revealed that increasing the concentration of a UV absorber (UVA) decreased both the crosslink density and the cure rate due to competition for the incident photons between the photoinitiator and the UVA, whereas including a hindered amine light stabilizer (HALS) hardly affected either the cure conversion or the cure rate due to its very low absorption of 365 nm. This result was confirmed by FTIR-ATR spectroscopy and UV-visible spectroscopy analyses. QUV ageing experiments showed that the cure conversion and durability were the highest for the UVA/HALS formulation at a ratio of 1 : 2, which is due to their synergistic action.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1225-1228
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• 2005

Barrier ribs in the plasma display panel(PDP) function to maintain the discharge space between the glass plates as well as to prevent optical crosstalk. Patterning of barrier ribs is one of unique processes for making PDP. In this work photosensitive barrier rib pastes were prepared by incorporating binder polymer, solvent, functional monomers photoinitiator, and barrier rib powder of which surface was treated with fumed silica particles. Study on the function of materials for the barrier rib paste were undertaken. After optimization of paste formulation and photolithographic process, it was found that photolithographic patterning of barrier ribs with photosensitive barrier rib green sheet could be used in the fabrication of high resolution PDP.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.11
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• pp.1507-1515
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• 2004

Washable wool was developed using environmental-friendly spray UV-cure technique. Photocrosslinkable polymer, dextran-methacrylate, was synthesized starting from natural biopolymer, dextran. The aqueous solution of dextran-methacrylate was applied to wool fabric with various concentrations to find out the optimum condition in minimizing felting shrinkage. The wool fabric subsequently cured by 365 nm UV, The effects of UV-cure time and photoinitiator concentration on felting behavior of wool were examined. As the concentration of dextran-methacrylate increased, the felting shrinkage decreased gradually. At concentration 0.5g/ml, the felting shrinkage of wool was negligible. Other properties such as air permeability, moisture content, wrinkle recovery, thickness and wettability were also evaluated. The surface coating of dextran polymer onto wool fiber was identified by SEM.

• Textile Coloration and Finishing
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• v.21 no.2
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• pp.40-47
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• 2009

Dimethylaminopropyl methacryamide was photografted onto PET fabrics by continuous UV irradiation under ambient conditions. Several factors affecting the photografting were studied including irradiation energy, monomer and photoinitiator concentrations. ATR and ESCA analysis showed the successful grafting of the monomer onto the PET surface. The grafted PET fabrics showed higher zeta potentials below pH 7 compared with the ungrafted PET. The dyeability of the grafted PET fabrics to two $\alpha$-bromoacrylamide reactive dyes was investigated under various dyeing conditions including dye concentration, pH, dyeing temperature and time. The grafting imparted the reactive dyeability to PET fabrics, which was proportional to the grafted monomer content. The reactive dyeing behavior of the grafted PET fabrics was similar to that of conventional wool fabrics.

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.9-15
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• 2007

As the development of nanotechnology, the use of composite resins which containing nanofillers becomes popular. The purpose of this study was to test the degree of polymerization of nanofillercontaining composite resins. For the study, three different nanofiller-containing composite resins and two different light-curing units were used. To evaluate the degree of polymerization, the maximum polymerization shrinkage taking place during the light curing, and the microhardness, after the light curing, were measured. As results, two light-curing units exhibited a similar emission spectrum to that of the included photoinitiator, camphorquinone. The only difference between the light-curing units were the width of the emission spectrum. Three different composite resins showed different microhardness values. Among them, Grandio showed the greatest microhardness value. However, there was less microhardness difference on the top and bottom surfaces due to the difference of the light-curing units. The maximum polymerization shrinkage values were also similar in the tested specimens regardless of the difference of the light-curing units. However, Grandio showed the least polymerization shrinkage. According to the manufacturers' data, Grandio showed the highest filler content(vol%).