• Title/Summary/Keyword: cinnamate

Search Result 94, Processing Time 0.038 seconds

Effect of Plasticization of Poly(Vinyl Cinnamate) on Liquid Crystal Orientation Stability

  • Hah, Hyun-Dae;Sung, Shi-Joon;Cho, Ki-Yun;Kim, Won-Sun;Jeong, Yong-Cheol;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2005.07b
    • /
    • pp.1518-1522
    • /
    • 2005
  • A cinnamate group is a well-known compound group used in the dimerization reaction by ultraviolet irradiation, and cinnamate polymers are studied as photoalignment materials. In this study, the radical reaction of cinnamate side groups attached to a flexible polymer backbone is considered feasible using thermal energy. To induce the thermal reaction of cinnamate side groups, we modified the flexibility of poly(vinyl cinnamate) by introducing a plasticizer into the polymers and investigated the thermal reaction behavior of cinnamate side groups. The plasticization of poly(vinyl cinnamate) makes the induction of the thermal reaction of cinnamate side groups easier than that of unmodified poly(vinyl cinnamate). The thermal reaction of cinnamate side groups is closely related to the enhancement of the thermal stability of the liquid crystal orientation of polymer films with polarized UV irradiation.

  • PDF

Thermal reaction of cinnamate oligomers and their effect on the orientational stability of liquid crystals

  • Hah, Hyun-Dae;Sung, Shi-Joon;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2007.08a
    • /
    • pp.493-495
    • /
    • 2007
  • Cinnamate groups are well-known for a dimerization reaction upon exposure to ultraviolet irradiation and a thermal reaction after being heated. In this study, to verify the thermal reaction of the cinnamate group in detail, we investigated the thermal crosslinking of cinnamate oligomers. The thermal reaction of cinnamate oligomers of low molecular weight is induced more readily by thermal energy compared with that of cinnamate polymers. The orientation of the liquid crystal depended on the length of the spacers in the cinnamate oligomers.

  • PDF

The Production of Methyl Trans-cinnamate in the Submerged Cultures of Tricholoma matsutake Mycelia

  • Park, Youngki;Lee, Wi Young;Ahn, Jin Kwon
    • Journal of the Korean Wood Science and Technology
    • /
    • v.35 no.5
    • /
    • pp.109-117
    • /
    • 2007
  • Methyl trans-cinnamate is a significant flavor compound of Tricholoma matsutake. Attempts were made to produce this compound by culturing the mycelium using submerged culture. No methyl trans-cinnamate could be detected when the mycelium was cultured in the basal liquid medium. However, the addition of Pinus desiflora extracts to the medium, methyl trans-cinnamate was largely produced. To find out compounds or fractions inducing methyl trans-cinnamate, dichloromethane fraction obtained from the wood extracts of P. densiflora was subjected to column chromatography. Three sub-fractions were obtained from the $CH_2CI_2$ fraction. Submerged cultured mycelium treated with sub-fraction 1 has the highest content of methyl trans-cinnamate. Maximum methyl trans-cinnamate $(470.2{\mu}g/g)$ was obtained when the first sub-fraction of dichloromethane fraction of the P. densiflora wood extracts was added to the medium. This indicates that wood extracts of P. densiflora contains inducer of the methyl trans-cinnamate production in the T. matsutake submerged culture.

Two different reaction mechanisms of cinnamate side groups attached to the various polymer backbones

  • Hah, Hyun-Dae;Sung, Shi-Joon;Cho, Ki-Yun;Jeong, Yong-Cheol;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.772-775
    • /
    • 2006
  • Cinnamate polymers are well known photoreactive polymers due to [2+2] cycloaddition reaction of cinnamate side group. In this work, we have found that the cinnamate side groups could be also reacted by thermal energy, and this reaction is presumed to attribute to the radical reaction of carbon double bond in the cinnamate groups. Contrary to the photocycloaddition reaction of the cinnamate side groups, the thermal reaction of cinnamate side group was closely related to the flexibility of polymer backbone. The difference of the mechanism between the photocycloaddition reaction and thermal crosslinking reaction was confirmed by $^1H-NMR$$ and $^{13}C-NMR$ analysis of the model compound.

  • PDF

Dimerization Behavior of Cinnamate Group attached to Flexible Polymer Backbone and Its Application to Liquid Crystal Alignment

  • Sung, Shi-Joon;Cho, Ki-Yun;Hah, Hyun-Dae;Kim, Won-Sun;Jeong, Yong-Cheol;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2004.08a
    • /
    • pp.1163-1166
    • /
    • 2004
  • Cinnamate group is well-known for the dimerization reaction by ultra-violet irradiation and cinnamate polymers are studied for photo-alignment materials. The cinnamate groups of flexible polymer are found to produce LC alignment parallel to polarization direction of ultra-violet light, which is contrary to the LC orientation on conventional cinnamate polymers. The un-reacted cinnamate groups in the flexible polymer are also found to participate in cycloadducts formation by additional thermal reaction that preserves the orientation of cycloadducts, leading to the enhancement of thermal stability of LC alignment.

  • PDF

Photocure Reactions of Photoreactive Prepolymers with Cinnamate Groups

  • Kim, Whan-Gun
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.3
    • /
    • pp.993-999
    • /
    • 2011
  • The photoreactive prepolymers with multifunctional cinnamate and bisphenol Atype cinnamate groups that could perform photodimerization without photoinitiators were synthesized by the reaction of t-cinnamic acids (CAs) and epoxy resins. Their photocure reaction rates and the extent of reaction conversion were measured with Fourier transform infrared spectroscopy, and these increased with the intensity of UVirradiation. The experimental data of these reaction rates showed the characteristics of nth-order kinetics reaction, and all kinetic constants of each photoreactive polymer with this equation were summarized. Although the GTR-1800-HCA and KWG1-EP-HCA with hydroxyl group substituted cinnamate showed lower reaction conversion rates and rate constant than GTR-1800-CA and KWG1-EP-CAwith an unsubstituted cinnamate group, GTR-1800-MCAand KWG1-EP-MCAwith methoxy group substituted cinnamate showed similar and higher reaction conversion rates than the former, respectively. These results were explained in terms of segmental mobility for photopolymerization by molecular interactions.

Photo-Alignment Using Polyimide Containing Methoxy Cinnamate Derivatives

  • Kim, Su-Young;Shin, Sung-Eui;Shin, Dong-Myung
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.668-671
    • /
    • 2009
  • Photosensitive polyimide containing methoxy cinnamate derivatives as a photo-alignment layer is investigated. The anisotropy of alignment layer was induced by irradiation linearly polarized UV (LPUV). We studied the effect of the methoxy cinnamate groups on alignment LCs.

  • PDF

Synthesis of Abscisic Acid Analogs and Their Biological Activity on Growth of Rice Seedling (합성 ABA 유도체의 벼 유묘 생장저해 작용)

  • Lee, Sang-Kap
    • Korean Journal of Environmental Agriculture
    • /
    • v.16 no.3
    • /
    • pp.269-273
    • /
    • 1997
  • This research aims at developing a new plant growth inhibitors related to abscisic acid by means of esterification of (S)-(+)-ABA with p-hydroxy methyl cinnamate and umbelliferone, and testing its biological activity on growth of rice seedlings. The over-all yield of ABA-methyl cinnamate(AC) and ABA-umbelliferone(AC) ester compounds were 83% and 78%, respectively. The growth inhibition activity of these synthetic compounds were shown about 3 to 10 times(AC) and 10 to 30 times(AU) higher than (S)-(+)-ABA.

  • PDF

Changes of Methyl trans-cinnamate Levels During Fruit-body Development in Tricholoma matsutake

  • Lee, Wi Young;Park, Youngki;Ahn, Jin Kwon;Ka, Kang Hyeon
    • Journal of Korean Society of Forest Science
    • /
    • v.94 no.5 s.162
    • /
    • pp.330-333
    • /
    • 2005
  • The relationship between the contents of methyl trans-cinnamate and the ratio of DP/DS (diameter of pileus / diameter of stalk) in the fruit-body of Tricholoma matsutake during its development was investigated. The stages of development were divided as follows: stage A is less than 1, stage B is from 1 to less than 2, stage C is from 2 to less than 3, and stage D is more than 3 of the values of DP/DS. The contents of methyl trans-cinnamate in pileus and stalk of pine mushroom ranged from $77{\mu}g/g$ to $824{\mu}g/g$ and from $7.6{\mu}g/g$ to $22.4{\mu}g/g$, respectively during its development. In the part of pileus, there is no relevance of the methyl trans-cinnamate content of pine mushroom between the stage A and B, but there was significantly different among the stage of B, C and D. In the case of stalk, the relevance of the methyl trans-cinnamate content of pine mushroom between stage D and other stages showed a low difference. In addition, as pileus of pine mushroom developed the level of the aroma compound increased as well and showed higher correlation relationship ($r^2=0.877$) between the contents of methyl trans-cinnamate in the pileus and the ratio of DP/DS. From the results of this study, we can conclude that the aromatic component of pine mushroom can be deduced from the value of DP/DS, which indicates the stage of the development appearance.

Pixel-Isolation Walls of Liquid Crystal Display Formed by Anisotropic Photoreaction of the Prepolymers Containing Cinnamate Moiety

  • Jung, Eun-Ae;Sung, Shi-Joon;Cho, Kuk-Young;Kim, Dae-Hwan;Son, Dae-Ho;Kang, Jin-Kyu
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.879-882
    • /
    • 2009
  • A pixel isolation wall of liquid crystal display is fabricated by the anisotropic photoreaction of a cinnamate based prepolymer. The various oligomers containing a cinnamate moiety were synthesized and used for the formation of the pixel isolation wall. The anisotropic photoreaction of cinnamate moiety was closely related with the liquid crystal orientation at the polymer wall boundary.

  • PDF