• Elastomers and Composites
• /
• v.54 no.3
• /
• pp.225-231
• /
• 2019

Bio-based polyester polyol was synthesized via esterification between azelaic acid and isosorbide. After esterification, bio-based polyurethanes were synthesized using polyester polyol, 1,3-propanediol as the chain extender, and 4,4'-diphenylmethane diisocyanate, in mixing ratios of 1:1:1.5, 1:1:1.8, 1:1:2, and 1:1:2.3. The bio TPU (Thermoplastic Polyurethane) samples were characterized by using FT-IR (Fourier Transform Infrared Spectroscopy), TGA (Thermal Gravimetric Analysis), DSC (Differential Scanning Calorimetry), and GPC (Gel Permeation Chromatography). The mechanical properties (tensile stress and hardness) were obtained by using UTM, a Shore A tester, and a Taber abrasion tester. The viscoelastic properties were tested by an Rubber Processing Analyzer in dynamic strain sweep and dynamic frequency test modes. The chemical resistance was tested with methanol by using the swelling test method. Based on these results, the bio TPU synthesized with the ratio of 1:1:2.3, referred to as TPU 4, showed the highest thermal decomposition temperature, the largest molecular weight, and most compact matrix structure due to the highest ratio of the hard segment in the molecular structure. It also presented the highest tensile strength, the largest elongation, and the best viscoelastic properties among the different bio TPUs synthesized herein.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.6
• /
• pp.1317-1324
• /
• 2009

Asymmetric transfer hydrogenation of α-functionalized arylketones has been studied. The chiral Rh-catalyst effectively performed in transfer hydrogenation of $\alpha$-mesyloxyketones with an azeotropic mixture of formic acid/triethylamine to produce optically active 1-arylethandiols with excellent enantioselectivity.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.12
• /
• pp.4191-4193
• /
• 2012

• Korean Journal of Pharmacognosy
• /
• v.32 no.3 s.126
• /
• pp.219-225
• /
• 2001

The water extracts of 82 Korean medicinal herbs were examined for the binding affinity on the recombinant human muscarinic acetylcholine receptor subtype 1 $(mAChR-M_1)$ produced from the CHO (Chinese Hamster Ovary) cell line. Of those tested, the extracts of Coptidis Rhizoma, Phellodendri Cortex, Hedyotis Herba and of Terminariae Fructus were found to exhibit a significant competition with $[^3H]$ N-methyl-scopolamine for the specific binding to $mAChR-M_1$ in a dose dependent manner, respectively.

• Korean Journal of Pharmacognosy
• /
• v.32 no.3 s.126
• /
• pp.212-218
• /
• 2001

The water extracts of 82 Korean medicinal herbs were prepared and were examined for the binding affinity on the glycine binding site of NMDA (N-methyl-D-aspartate) receptor prepared by the synaptic membranes from the forebrains of male Sprague-Dawley rats. Among the tested, the extracts of Dioscoreae Rhizoma, Hoveniae Semen cum Fructus, Astragali Radix, Armeniacae Semen, Huttuynia cordata Herba, Acanthopanacis Cortex, Aurantii nobilis Pericarpium, Phellinus linteus, Amomi Fructus, Artemisiae capillaris Herba, Polyporus, Agastachis Herba and of Galli Stomachichum Corium were found to exhibit significant competitions with $[^3H]-MDL$ 105,519 for the glycine specific binding site of NMDA receptor in a dose dependent manner, respectively.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.496-496
• /
• 2003

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.477-477
• /
• 2003

• Macromolecular Research
• /
• v.16 no.6
• /
• pp.570-573
• /
• 2008

See Full Text

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.600-600
• /
• 2003

• 한국생물공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.431-432
• /
• 2005