• Macromolecular Research
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• 제11권2호
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• pp.80-86
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• 2003

The polymerization of a cyclopolymerizable disubstituted dipropargyl ether, his(3-trimethylsilyl-2-propynyl)ether (BTPE), was attempted by various transition metal catalysts. The yield for the polymerization of BTPE was generally low, which is possibly due to the steric hindrance of bulky substituents. In general, the catalytic activities of Mo-based catalysts were found to be greater than those of W-based catalysts. The highest yield was obtained when the MoCl$_{5}$,-EtAlCl$_2$(1:2) catalyst system was used. The copolymerization of BTPE and diethyl dipropargylmalonate yielded a random copolymer with conjugated polymer backbone. However the polymers were partially desilylated, depending on the reaction conditions. The thermal and morphological properties of the resulting polymers were also discussed.d.

• Bulletin of the Korean Chemical Society
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• 제17권3호
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• pp.257-262
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• 1996

p-(2-Vinyloxyethoxy)benzylidenemalononitrile 2 and methyl p-(2-vinyloxyethoxy)benzylidenecyanoacetate 3 was prepared by the condensation of p-(2-vinyloxyethoxy)benzaldehyde 1 with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 2 and 3 polymerized quantitatively with radical initiators in γ-butyrolactone solution at 65 ℃. The trisubstituted terminal double bond participated in the vinyl polymerization and radical polymerization of 2 and 3 led to swelling polymers 4 and 5 that were not soluble in common solvents due to cross-linking. Under the same polymerization conditions ethylvinyl ether polymerized well with model compounds of p-methoxybenzylidenemalononitrile 6 and methyl p-methoxybenzylidenecyanoacetate 7, respectively, to give 1:1 alternating copolymers 8 and 9 in high yields. Polymers 4 and 5 showed a thermal stability up to 300 ℃ without any characteristic Tg peaks in DSC thermograms. Alternating copolymers 8 and 9 were soluble in common solvents such as acetone and DMSO, and the inherent viscosities of the polymers were in the range of 0.36-0.74 dL/g. Films cast from acetone solution were cloudy and tough and Tg values obtained from DSC thermograms were in the range of 59-60 ℃.

• 공업화학
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• 제10권6호
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• pp.902-906
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• 1999

메틸셀루로스를 호스트고분자로 하고 copper(II) percolate를 산화제로 사용하여 기상상태에서 직접중합방법으로 전도성 복합필름을 합성하였다. 필름으로서 우수한 성형성과 기계강도를 갖고 있는 메틸셀루로즈는 PVA와 키토산과는 달리 피롤에 대하여 높은 친화성을 나타내어서 기상중합시 호스트고분자로 적합하였다. 기상중합법으로 합성된 폴리피롤은 복합재료 내에서 전도성네트워크를 형성하여 전도성 복합필름의 전기전도도는 $10^{-1}-10^{-7}S/cm$를 나타내었다. 피롤이 호스트고분자 내에서의 폴리피롤로 중합이 되는 정도를 UV-vis분광계로 확인하였다. 전도성 복합필름의 전기전도도와 기계강도는 산화제의 농도와 합성시간에 크게 의존하였다. TGA분석결과는 호스트고분자 내에 형성된 폴리피롤은 복합재료의 열적 안정성에 영향을 미치지 않는다. 전자현미경 분석결과 폴리피롤이 복합재료 내에 균일하게 침투하여 분산되어 있음을 나타내었다. DMA를 사용하여 폴리피롤과 호스트고분자와의 상용성을 조사하였으며 dynamic mechanical analysis(DMA) 분석결과 복합재료 내에서 폴리피롤의 함량이 증가되면서 상용성이 점진적으로 저하되었다.

• 한국의류학회지
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• 제17권3호
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• pp.347-358
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• 1993

Graft copolymerization of MMN4-VP onto cotton fiber using Ce(IV) salt as an initiator and triton X-100 as an emulsifier was performed under various polymerization conditions. In cograft polymerization, the polymeization behavior according to variation of 4-VP feed composition and the characteristics of MMA/4-VP graft polymer such as affinity for acid dye owing to cationization of cotton, antibacterial activity and thermal behavior were investigated. The results of this study were as follows : 1. While in copolymerization of MMA and 4-VP, 4-VP content in copolymer was more than that of monomer feed composition. 2. Increasing 4-VP content, graft yield was decreased, but graft efficiency was increased. In case of MMA/4-VP graft polymerization, the highest graft yield was obtained at higher CAN concentration than in MMA graft polymerization, the reason is that the behavior of 4-VP was disturbed by Ce(IV) sail 3. Elevation of temperature resulted in increase of graft yield and the apparent activation energy of MMA/4-VP graft polymerization was higher than that of MMA graft polymerization. 4. MMA/4-VP grafted cotton fiber showed affinity for acid dye, antibacterial activity and higher moisture regain than MMA grafted cotton fiber. MMA/4-VP grafted cotton fabric showed improvement of wrinkle recovery up to 40~50% graft yield and decreased thereafter. MMA/4-VP and MMA grafted cotton fabric did not showed significant difference in wrinkle recovery and stiffness.

• Nuclear Engineering and Technology
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• 제4권4호
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• pp.301-305
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• 1972

육송 미송 포플라 등 국산 연질 목재에 단량체 또는 단량체 혼합물을 촉매와 함께 침투시키고 열중합함에 있어서 시간에 따르는 중합율을 구하고 이것을 방사선 중합으로 WPC를 제조할 때 얻은 간과 비교 검토하여 다음과 같은 결론을 얻었다. (1) 중합율로 보아서는 육송, 미송이 포플라보다 좋으며 M.M.A.가 다른 단량체보다 효과적이다. (2) 비닐아세테이트는 일반적으로 열중합에 의한 중합율이 저조한 편이며 특히 포플라에 침투된 경우 매우 낮아 W.P.C.를 만들기 곤란하다. 그러나 비닐아세테이트와 M.M.A.를 같이 침투시키면 나무종류나 중합방법에 별 관계없이 매우 빨리 중합하여 가장 효과적이다. (3) 나무에 침투된 단량체나 단량체 혼합물의 중합의 경향은 나무가 많은량의 수지를 함유하지 않는다면 중합방법에 관계없이 단량체나 단량체 혼합물 자체만일때의 중합의 경향과 같다.

• 공업화학
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• 제19권3호
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• pp.345-350
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• 2008

고분자함침콘크리트(PIC)는 물리화학적 물성뿐만 아니라 기계적 강도가 우수한 재료로서 성형된 일반 콘크리트를 변조하여 제조한다. PIC 제조공정은 성형된 공시체의 건조, 단량체의 함침, 중합공정으로 구성된다. PIC 제조공정 중 고분자 중합공정은 지금까지 주로 열 및 수중중합방법을 사용하여 콘크리트 내부의 온도구배가 크고 라디칼 생성이 억제되어 불균일한 중합을 초래하였다. 본 연구에서는 마이크로파를 이용한 중합 반응기를 제작하여 스티렌/메틸메타아크릴레이트(MMA) 1 : 1의 혼합물을 단량체로 사용한 PIC 제조의 중합공정에 사용하였다. 그 결과 열중합보다 매우 균일한 PIC를 제조할 수 있었으며, 30% 이상 중합도가 증가하였고, 공시체보다 기계적 압축강도는 600% ($800{\sim}1200kg_f/cm^2$)까지 증가하였으며, 내산성은 20% 이상 증가하였다. 또한 개시제는 1% 이하로 사용할 수 있었고 중합의 최적 조건은 400 W, 2450 MHz의 radiation 조사로 최적 온도는 $120^{\circ}C$였다.

• Macromolecular Research
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• 제8권6호
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• pp.261-267
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• 2000

It is well known that poly(cyclohexylene dimethylene terephthalate) (PCT) is used as the engineering plastics with high melting temperature and fast crystallization rate compared with poly(butylene terephthalate)(PBT). However, poor thermal stability of PCT has limited its practical application due to the drastic decrease of molecular weight during the processing temperature. In order to improve the thermal stability of PCT homopolymer, the copolymer of PCT and PBT was synthesized and the thermal properties of the copolymer have been studied. P(CT/BT) copolymer was obtained by condensation polymerization of DMT, CHDM, and 1,4-butanediol. The chemical structure and composition of the copolymer was investigated by FTIR and NMR analysis. The thermal behavior of copolymer was studied using DSC and it was found that the crystallization-melting behavior of the copolymer was observed for the whole composition range. TGA analysis exhibited that P(CT/BT) copolymer is more stable at the initial stage of thermal decomposition compared with PCT and PBT homopolymers.

• 폴리머
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• 제34권4호
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• pp.369-375
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• 2010

용융 중합법을 이용하여 말단에 메틸 말레이미드(methyl maleimide) 반응성기를 가지며 방향족 에스터와 아 미드 결합을 포함하는 액정(liquid crystal, LC)을 합성하였다. 합성된 액정은 용액 캐스팅과 열처리를 거쳐 열경화 성 액정(liquid crystalline thermoset, LCT) 필름으로 제조되었다. 합성된 LC 및 LCT는 적외선 분광기(FTIR), 시차주사 열량계(DSC), 열중량 분석기(TGA), 열-기계 분석기(TMA), X-선 회절기(XRD) 및 가열판이 부착된 편광 현미경(POM) 등을 이용해서 각각 특성 분석을 하였다. 합성된 모든 액정은 스멕틱(smectic) 상을 보였으며 LC와 LCT들의 열적 성질은 주로 주사슬에 포함된 메소젠 구조에 영향을 받았다. 열팽창 계수(coefficients of thermal expansion, CTE)는 27.72~50.95 ppm/$^{\circ}C$ 사이의 값을 보였다.

• Bulletin of the Korean Chemical Society
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• 제16권4호
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• pp.326-331
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• 1995

Poly(enaryloxynitriles) containing Schiff bases were prepared from p-bis(1-chloro-2,2-dicyanovinyl)benzene (2) and various aromatic diols having Schiff base moiety by interfacial polymerization. The chemical structure of the polymers was confirmed through synthesis of their corresponding model compounds. All the polymers were soluble in polar aprotic solvents and their brittle films were cast from DMF solution. They showed a large exotherm around 340 ℃ attributable to the chemical change of dicyanovinyl group. Especially, curing of azomethine group was observed to occur at 390 ℃ by differential scanning calorimetry. According to the thermogravimetric analyses, they exhibited excellent thermal stability with 60-90% residual weight at 500 ℃ in nitrogen.

• Fibers and Polymers
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• 제2권2호
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• pp.75-80
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• 2001

The thermal degradation of poly(ethylene terephthalate-co-isophthalate)s (PETIs) is investigated by using isothermal thermogravimetric analysis at the temperature range of 280-31$0^{\circ}C$. The degradation rate of PETIs is increased as the mole ratio of ethylene isophthaloyl (EI) units in PETIs increases. The activation energies for the thermal degradation of poly(ethylene terephthalate), PETI(5/5), and poly(ethylene isophthalate) are 33.4, 16.6, and 8.9 kcal/mole, respectively. The degradation rate of PETIs is influenced by their volatile cyclic oligomer components formed during the polymerization and the thermal degradation. It is simulated by the rotational isomeric state model that the content of cyclic dimer in PETIs, which is the most volatile cyclic oligomer component, increases with the EI units in PETIs.