• 폴리머
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• 제35권6호
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• pp.599-604
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• 2011

폴리에스테르 유연기판 제조를 위하여 PET-PEN 공중합체를 합성하고 이들의 형태학적 변화가 유연기판 특성에 미치는 영향을 살펴보았다. 합성된 PET-PEN 공중합체는 DMT/NDC의 조성비에 따라 공중합체 block sequence가 달라짐을 확인하였다. 공중합체에 PET-PEN과 PEN의 block sequence가 증가할수록 유리전이온도가 증가하며 이에 따라 유연기판의 치수안정성이 증가됨을 확인하였으며 DMT/NDC의 조성비가 50/50인 경우, 열팽창계수(CTE)가 최소가 됨을 확인하였다. 합성된 PET-PEN 공중합체는 광투과 특성이 80% 이상을 유지하며 1시간 동안 $280^{\circ}C$에서의 열안정성도 0.4 wt% 이내를 유지하여 유연기판으로 적용이 가능함을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.193-196
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• 2004

The peptide Arg-Gly-Asp (RGD) was immobilized through their amino terminus to ends of a sugar bearing copolymer, producing a functional hybrid copolymer. Poly(N-p-vinylbenzyl-D-maltonamide-co-6-(p-vinylbenzamido)-hexanoic acid-g-GRGDS) [p(VMA-co-VBGRGDS)] promoted the attachment and growth of NIH fibroblast cells. The interaction between fibroblast cells and p(VMA-co- VBGRGDS) copolymer resulted in effective cell attachment, proliferation, and morphological changes by introduction of a GRGDS sequence. Moreover, when pretreated with soluble RGD monomer, attachment of fibroblast cells was suppressed approximately 50% from that of the p(VMA-co-VBGRGDS) surface.

• 공업화학
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• 제4권4호
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• pp.770-775
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• 1993

에틸렌글리콜과 1, 4-시클로헥산디메탄올의 테레프탈산 공중합체인, poly(ethylene terephthalate-co-1, 4-cyelohexylene dimethylene terephthalate), P(ET-CT)의 화학 구조를 고분해능 NMR 분석을 통하여 조사하였다. $^1H$ NMR 분석에서 메칠렌기에 의한 chemical shift가 ET, 트란스 CT, 및 시스 CT로 분리됨에 따라 공중합조성 및 이성질체의 비율을 구할 수 있었다. $^{13}C$ NMR 분석에서 카르보닐기에 연결된 벤젠기의 탄소가 diad로 분리됨에 따라 공중합 연쇄 분포(copolymer sequence distribution)를 구한 결과, P(ET-CT) 공중합체는 랜덤공중합체임이 판명되었다. 아울러 랜덤 통계식을 이용하여 공중합 연쇄의 분포 및 평균길이를 구할 수 있었다.

• Fibers and Polymers
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• 제3권1호
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• pp.8-13
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• 2002

The effect of block sequence on the self-assembly of ABC-type triblock copolymers in the ordered state is investigated using an isothermal-isobaric molecular dynamics simulation. The block sequence has an important effect ,on the ]norphology of ABC triblock copolymers. Different morphologies are observed depending on the block sequence as well as the block composition. The triblock copolymers with the volume fraction of 1 : 1 : 1 ($f_A$=$f_B$=$f_C$= 0.33) show the three phase and four layered lamellar structures irrespective of the block sequence. The $A_{32}$$B_{16}$$C_{32}$triblock copolymer with $f_B$=0.2 shows a morphology In which cylinders of midblock B are formed at the interface between A and C lamellae, whereas the morphology of triblock copolymer $B_{16}$$C_{32}$ $A_{32}$ and $C_{32}$ $A_{32}$ $B_{16}$ show a cylindrical core-shell structure and a lamellar type morphology, respectively. The $A_{20}$$B_{40}$$C_{20}$the triblock copolymer with the block B as a major component shows a tricontinuous structure, whereas both $B_{40}$$C_{20}$$A_{20}$ and $C_{20}$$A_{20}$$B_{40}$ triblock coolymers exhibit the lamellar structures. When the block B has larger volrome fraction with $f_B$=0.75, the matrix is composed of block B, and other two blocks A and C form spherical domains.

• 폴리머
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• 제24권5호
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• pp.664-672
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• 2000

Poly(ethylene naphthalate)/poly($\varepsilon$-caprolactone) (PEN/PCL)의 용융 블렌딩시 필연적으로 발현되는 상호에스테르 교환반응은 PEN/PCL 공중합체를 형성하게 된다. 블렌드의 조성비, 상호에스테르 교환반응 조건 그리고 사용된 촉매가 형성된 공중합체의 randomness와 평균 sequence length에 미치는 영향을 살펴보고 이들과 블렌드의 생분해 특성과의 관계를 확인하여 보았다. 용융 블렌딩에 의하여 얻어진 PEN/PCL 공중합체는 randomness가 0과 1사이인 것으로 보아 블럭 공중합체임을 알 수 있었으며, 열처리 시간과 온도의 증가 그리고 촉매의 첨가에 의하여 randomness가 1에 근접하고 PEN과 PCL의 평균 sequence length 모두 감소하는 것으로 보아 랜덤 공중합체로 변화됨을 확인할 수 있었다. 이러한 공중합체의 생성과 랜덤화는 PEN/PCL 블렌드의 생분해성 감소를 초래함을 알 수 있었다.

• Fibers and Polymers
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• 제5권3호
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• pp.245-251
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• 2004

Poly(trimethylene terephthalate-co-trimethylene 2,6-naphthalate)s (P(TT-co-TN)s) with various copolymer composition were synthesized, and their chain structure, thermal property and crystalline structure were investigated by using $^1$H-NMR spectroscopy, differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), respectively. It was found from sequence analysis that all the P(TT-co-TN) copolymers synthesized have a statistical random distribution of TT and TN units. It was also observed from DSC thermograms that the glass transition temperature increases linearly with increasing the TN comonomer content, whereas the melting temperature of copolymer decreases with increasing the corresponding comonomer content in respective PTT- and PTN-based copolymer, showing pseudo-eutectic melting behavior. All the samples melt-crystallized isothermally except for P(TT-co-66 mol % TN) exhibit multiple melting endotherms and clear X-ray diffraction patterns. The multiple melting behavior originates from the dual lamellar population and/or the melting-recrystallization-remelting. The X-ray diffraction patterns are largely divided into two classes depending on the copolymer composition, i.e., PTT and PTN $\beta$-form diffraction patterns, without exhibiting cocrystallization.

• Macromolecular Research
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• 제16권3호
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• pp.231-237
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• 2008

Biodegradable poly($\varepsilon$-caprolactone-co-L-lactide)-b-poly(ethylene glycol) (PCLA-b-PEG) copolymers were synthesized via solution polymerization by varying the feed composition of $\varepsilon$-caprolactone ($\varepsilon$-CL) and L-lactide (LLA) ($\varepsilon$-CL: LLA= 10:0, 7:3, 5:5, 3:7, 0: 10). The feed ratio based on weight is in accordance with the copolymer composition except for the case of $\varepsilon$-CL: LLA=3:7 (C3L7), which was verified by $^1H$-NMR. Two different approaches were used for the exceptional case, which is an extension of the reaction time or the sequential introduction of the monomer. A copolymer composition of $\varepsilon$-CL: LLA=3:7 could be obtained in either case. The chemical microstructure of PCLA-b-PEG was determined using the $^{13}C$-NMR spectra and the effect of the sequential structure on the thermal properties and crystallinity were examined. Despite the same composition ratio of the copolymer, the microstructure can differ according to the reaction conditions.

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.85-87
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• 1991

Poly[(tri-O-acetyl-D-glucal)-alt-(maleic anhydride)] was synthesized by free radical copolymerizations of the relevant comonomers. The alternating sequence of the copolymer was confirmed by $^1$H-NMR, elemental analysis, and titration of anhydride groups incorporated into the copolymer. Hydrolysis of the copolymer under different conditions resulted in poly[(2-acetoxymethyl-3,4-diacetoxytetrahydropyran-5,6-diyl) (1,2-dicarboxyethylene)] and poly[(2-hydroxymethyl-3,4-dihydroxytetrahydropyran-5,6-diyl) (1,2-dicarboxyethylene)]. The cytotoxicities of these polymers measured against normal and tumor cells (3LL, B16) in vitro were found to be higher than that of DIVEMA, a prototype polymer having a high antitumor activity.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2616-2622
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• 2013

A novel zwitterionic monomer 3-[(2-acrylamido)dimethylammonio]propanesulfonate (DMADAS) was designed and synthesized in this study. Then it was polymerized with acrylamide (AM) by free radical polymerization in 0.5 mol/L NaCl solution with ammonium persulfate ($(NH_4)_2S_2O_8$) and sodium sulfate ($NaHSO_3$) as initiator. The structure and composition of DMADAS and acrylamide-3-[(2-acrylamido)-dimethylammonio]propanesulfonate copolymer (P-AM-DMADAS) were characterized by FT-IR spectroscopy, $^1H$ NMR and elemental analyses. Isoelectric point (IEP) of P-AM-DMADAS was tested by nanoparticle size and potential analyzer. Solution properties of copolymer were studied by reduced viscosity. Antipolyelectrolyte behavior was observed and was found to be enhanced with increasing DMADAS content in copolymer. The results showed that the viscosity of P-AM-DMADAS is 5.472 dl/g in pure water. Electrolyte was added, which weakened the mutual attraction between sulfonic acid group and quaternary ammonium group. The conformation became loose, which led to the increase of reduced viscosity. The ability of monovalent and divalent cation influencing the viscosity of zwitterionic copolymer obeyed the following sequence: $Li^+$ < $Na^+$ < $K^+$, $Mg^{2+}$ < $Ca^{2+}$ < $Ba^{2+}$, and that of anion is in the order: $Cl^-$ < $Br^-$ < $I^-$, $CO{_3}^{2-}$ > $SO{_3}^{2-}{\approx}SO{_4}^{2-}$.

• Macromolecular Research
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• 제9권4호
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• pp.185-196
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• 2001

The self-assembly of block copolymers can lead to a variety of ordered structures on a nanometer scale. In this article, the self-assembling behaviors of triblock copolymers in the melt and the selective solvent are described with the results obtained from the computer simulations. With the advances of computing power, computer simulations using molecular dynamics and Monte Carlo techniques make it possible to study very complicated phenomena observed in the self-assembly of triblock copolymer. 13king full advantage of the computer simulation based on well-defined model, the effects of various structural and thermodynamic parameters such as the copolymer composition, the block sequence, the pairwise interaction energies, and temperature on the self-assembly are discussed in some detail. Some simulation results are compared with experimental ones End analyzed by comparing them with the theoretical treatment.