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지방족 copolyester 및 copolyesteramide 의 합성과 분해성 (2)
김우식,현석희,전일련,강혜정,이치규,김승환 ( Woo Sik Kim,Seok Hee Hyun,Il Ryon Jeon,Hye Jung Kang,Chi Giu Lee,Sung Hwan Kim ) 한국공업화학회 1996 공업화학 Vol.7 No.3
이 연구에서는 촉매로서 tetraphenyltin을 사용하여 D,L-lactide (2-LA)와 β-methyl-δ-valerolactone (MVL)의 공중합체를 합성하고 그 물성을 조사하였다. 공중합체중의 lactic acid반복단위(LA)의 조성은 단량체 공급에서의 LA조성보다 높았다. 공중합체중의 그 조성은 공중합시간의 증가와 더불어 감소하였다. 그 공중합체의 수율과 분자량은 공급조성중의 LA의 증가와 더불어 증가하였다. 이들 결과는 공중합에 있어서 2-LA의 반응성이 MVL의 반응성보다 크다는 것을 뜻한다. 공중합체의 수평균분자량은 54,000에서 63,000의 범위에 있었고 다분산성지수는 1.7에서 2.1의 범위에 해당하였다. 공중합체는 융점을 나타내지 않았고 유리전이온도만 나타내었다. Lipase에 의한 공중합체의 분해성의 경향은 L-lactide-MVL 공중합체의 분해성의 경향과 거의 같았다. D,L-lactide (2-LA) was copolymerized with β-methyl-δ-valerolactone (MVL) using tetraphenyltin as a catalyst and the properties of the copolymers were investigated. The composition of the repeating unit of lactic acid in the copolymers was higher than that in the monomer feeds. The composition of the lactic acid unit in the copolymers decreased with increasing copolymerization time. The yield and the molecular weight of the copolymer increased with increasing 2-LA in the feed composition. These results suggest that the reactivity of 2-LA is larger than that of MVL. The number average molecular weight was in the range of 54,000 to 63,000 and the polydispersity index was in the range of 1.7 to 2.1. The copolymers did not show melting point, but glass transition temperature. The degradable tendency of the copolymers with lipase was almost equal to that of L-lactide-MVL copolymer.
곽기섭,김혜련,현석희,백창훈,김우식,임학상,전일련 한국고분자학회 2010 Macromolecular Research Vol.18 No.1
This paper describes the thermally enhanced in-plane alignment and other properties of liquid crystalline (LC) copolymers (1, 2, and 3) consisting of a methacrylate with a 2-styrylpyridine side group as a photocyclodimerizable group and a methacrylate with a methoxy biphenyl side group as a mesogenic group. 1H NMR spectroscopy indicated that the contents of the photoreactive monomer unit in copolymers 1, 2, and 3 were 0.65, 0.46 and 0.19(mole fraction), respectively. The copolymers in the film showed a transmittance of 92% at wavelengths > 450 nm,even at 100 oC, as well as thermal stability up to approximately 360 oC. Copolymers 1 and 2 gave a nematic texture at 155 and 150 oC, respectively, while copolymer 3 showed a smectic texture at 130 oC. The copolymer films aligned parallel to the linearly polarized UV(LPUV) light after LPUV light irradiation and subsequent thermal annealing. The respective in-plane order parameters of copolymers 1, 2, and 3 in the film at 315 nm were 0.65 at 0.001 J/cm2,0.59 at 0.01 J/cm2, and 0.48 at 0.025 J/cm2 by the same treatment in the LC temperature ranges. This suggests that the photoreactive LC copolymers not only have high optical transparency and good thermal stability but also have controllable, high in-plane alignment with the contents of the photoreactive monomer unit.