• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.21-24
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• 1998

흡수성 고분자는 주로 기저귀, 생리대, 농업용 뿌리 덮개 등에 사용되며, PAN(폴리아크릴 로니트릴) 그라프트 전분으로 대표되는 그라프트 공중합체와 가교된 아크릴레이트 고분자로 대표되는 수용성 단량체의 단중합체 또는 공중합체 등에 대한 연구가 가장 활발히 이루어져 왔다. 이들 고흡수성 재료들은 염용액에 대한 흡수도가 낮다는 단점이 있으며, 보다 강한 이온기를 도입하거나, 고흡수성 재료가 양쪽성을 나타낼 경우, 염에 대한 흡수도가 개선된다는 연구결과가 보고된바 있다. (중략)

• The Korean Journal of Rheology
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• v.9 no.4
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• pp.163-173
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• 1997

Polystyrene/polycarbonate 조성이 약 50/50인 3종류의 Poly(carbonate-g-styrene) 공중합체의 동적 탄성율, E*($\omega$)와 동적 스트레인-광학계수 O*($\omega$)을 유리전이 영역부근의 여러온도에서 동시에 측정하여 연구하였다. 두 개의 공중합체는 각각의 스티렌 그라프트쇄 에 5, 10 wt%의 MAH를 함유하고 있다. 이들 공중합체의 E*($\omega$)와 O*($\omega$)완화거동과 그라 프트 공중합체의 상용성과 연관하여 비교 고찰하였다. 공중합체들의 E*($\omega$)는 전형적인 무 정형 고분자의 유리전이 완하거동을 보였으며 정성적인 차이를 발견할수 없었다. 그러나 고 강도의 단일 tan$\delta$분산의 저주파수 영역에 미세분산을 나타내, 공중합체는 2상으로 분리되 어 있음이 추정되엇다. 폴리스티렌 그라프트체에 무수 말레인산 함유량이 증가함에 따라, 저 주파수 영역의 미세피크가 $\alpha$주분산에 병합되어 성분 고분자간의 상호 형동성이 증가함을 알수 있었다. 3공중합체의 유사한 기계적 특성과는 달리, 광학적 완화 스펙트럼 O*($\omega$)는 정 성적으로 명확한 차이를 보여 공중합체들의 광학완화 거동이 명확히 다름을 나타냈다. 기계 적 특성보다는 광학적 특성이 공중합체내의 성분 고분자의 미세한 완하 거동에 훨씬 민감한 응답을나타냈다. 이러한 특성적인 공중합체의 O*($\omega$)차이를 공중합체의 조성단일 고분자 PS, PC의 O*($\omega$)의 가성성을 가정하여 모사하였다 모사에서 구한 광학적 부분 기여 파라메 터를 사용하여 공중합체의 상용성을 고찰하였다.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.188-195
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• 1993

Polyelectrolyte complexes and graft copolymers as biomaterials were synthesized from the water soluble cellulose derivatives. Polyelectrolyte complexes have been prepared from carboxymethyl cellulose (CMC) and gelatin. Graft copolymers(Mc-g-AA) were synthesized by grafting acrylic acid (AA) onto methyl cellulose(MC). (Mc-g-AA) and gelatin polyelectrolyte complexes were also prepared. The optimum conditions of each sample were investigated after chemical crosslinking or heat treatment. The preliminary results show that these materials might be interesting for biomedical applications.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.453-456
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• 1998

고분자들을 배합하여 기계적, 물리적, 화학적 성질이 우수한 새로운 고분자 재료를 제조할 때 이들 고분자의 상용성을 증가시켜 줄 수 있는 상용화제의 존재가 필수적인데, 주로 블록이나 그라프트 공중합체들이 많이 이용되고 있다. 이러한 공중합체들은 아주 최소량이 사용되고서도 소기의 목적을 달성할 수 있어야 하는데, 이를 위해서는 이러한 공중합체들은 분자구조상 몇 가지 조건을 만족해야 한다. 예를 들면 계면에 존재하면서 넓은 표면적을 감싸주어야 하고 블렌드되는 고분자들과 아주 잘 섞여야 한다는 것 등이 그것이다. (중략)

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.757-767
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• 1996

Poly(alkyl acrylate-g-caprolactone) graft copolymers were prepared, and they were applied as compatibilizing agents for polycarbonate (PC) / poly(acrylonitrile-butadiene-styrene) (ABS) blends. The incompatible poly(alkyl acrylate) segment was incorporated into the graft copolymer in order to localize the copolymer at the PC/ABS interface. The blend containing 1 phr of the copolymer showed remarkable improvement in impact strength as well as in elongation at break. Impact improvement was more pronounced with a thinner test specimens of 1/8 inch thickness. Morphological study showed that the presence of the graft copolymer led to a smoother PC/ABS interface due to the interfacial enrichment of the graft copolymer.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.524-536
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• 1994

Chitosan is known to be a good biocompatible natural polymer. Polyethyleneglycol monomethacrylates(PEGM) were grafted onto chitosan and their reaction conditions and properties of the graft polymers obtained were estimated. Using ceric ammonium nitrate(CAN) as the initiator, the optimum condition for graft polymerization was determined amount of the initiator and monomer concentrations and reaction time. Grafting yields such as total conversion, the percentage of grafting and the efficiency of grafting were calculated and examined the optimum reaction condition for high grafting yields. The percentage of grafting and total conversion were maximum at condition that the concentration of initiator was $4{\sim}5{\times}10^{-3}M$, the concentration of monomer was 0.5~0.6M, the reaction time was 2~3 hours and the reaction temperature was about $40^{\circ}C$. Thermal characteristics, solubility for chitosan solvents and inherent viscosity of synthesized graft copolymers were investigated. In high initiator concentration, characteristics of chitosan were greatly diminshed. In case of inherent viscosities, chitosan-g-PE-90 was 2.81 dl/g, chitosan-g-PE-200, 3.01dl/g and chitosan-g-PE-350, 4.93dl/g. And a tendency of viscosity increase depending on the length of ethylene oxide residue was confirmed. Degree of swelling, tensile strength, elongation of membrane prepared from graft copolymers were determined. Properties of graft copolymers were affected by percentage of grafting and length of ethylene oxides residue in polyethylene glycol monomethacrylates. Tensile strength, elongation and degree of swelling of graft copolymers were remarkably improved than chitosan. As percentage of grafting increased, the amount of drug permeation was also increased.

• Polymer(Korea)
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• v.24 no.3
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• pp.306-313
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• 2000

Polycaprolactone (PCL) macromer containing terminal methacrylate group was synthesized by ring-opening polymerization. The number average molecular weight of PCL macromer was 11600 g/mole and polydispersity index was 1.09. The synthesized PCL macromer was copolymerized with styrene by stable free radical polymerization using 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), benzoyl peroxide, and well-defined poly(styrene-g-caprolactone)s were synthesized. The synthesized copolymers was characterized by $^1$H-NMR and gel permeation chromatography equipped with multiangle laser light scattering detector. Thermal properties of graft copolymers were investigated by DSC.

• Journal of the Korean Chemical Society
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• v.20 no.4
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• pp.309-315
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• 1976

An efficient separation method and the utilization of sericin are searched. Sericin was extracted with hot water from cocoons under atmospheric pressure. The separated sericin was gel-filtrated with Sephadex G-75 and G-150 at room temperature and at $70^{\circ}C$. The results indicated that sericin is consisted of only one fraction in elution diagram. In the graft copolymerization of acrylonitrile to sericin ceric ammonium nitrate was chosen as an initiatior. A maximum yield was obtained at certain concentration of the initiator confirming our previous experiments. Viscosity measurement of alkali-hydrolyzed graft copolymers indicated that the polyacrylonitrile graft had the molecular weight in the range of 7,000.

• Elastomers and Composites
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• v.48 no.1
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• pp.30-38
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• 2013

Polyolefin is one of the most important commodity polymers having excellent physical properties and cost competitiveness, which has continuously broadened their market in response to a heavy demand from industry. However, the lack of polarity in polyolefin has limited its applications, especially where interactions with other materials are important. In view of the above, the incorporation of polar functional groups in polyolefin has been widely attempted. Especially, the preparations of segmented modified polyolefin copolymers, such as block and graft copolymers have been extensively investigated, since the loss of the original properties of polyolefin can be minimized while the polar segments can endow interactions with other materials. Living radical polymerization (LRP) method can be one of the most attractive synthetic tools for the preparation of the modified polyolefin block or graft copolymers. In this review, progress on the preparation of the polyolefin based block or graft copolymers through LRP technique is briefly summarized.

• Polymer(Korea)
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• v.24 no.2
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• pp.174-181
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• 2000

The ACF/PP-g-AN copolymers were synthesized by the irradiational grafting of acrylonitrile onto ACF/PP hybrid fabric. The synthesis of the ACF/PP-g-AN copolymer was evidenced by the band of -C=N absorption peak at 2250 $cm^{-1}$ / and amidoximation was evidenced by the band of -OH and -NH$_2$ peak at 3450 $cm^{-1}$ / on FT-IR spectrum. The optimal time for the uranium ion adsorption equilibrium on ACF/PP-g-AN copolymers was 8 days and the optimal pH was 8. The adsorption capacities of ACF/PP-g-AN copolymers increased according to the content of amidoxime and were not varied even after more than 10 times of regeneration.