• Title, Summary, Keyword: Polymer precursor

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Swelling Behavior of Biodegradable Crosslinked Gel based on Poly(aspartic acid) and PEG-diepoxide

  • Min, Suk-Kee;Kim, Ji-Heung;Chung, Dong-Jun
    • Macromolecular research
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    • v.9 no.3
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    • pp.143-149
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    • 2001
  • Poly(aspartic acid), PASP, is a biodegradable, water-soluble polymer and offers a biodegradable alternative to polycarboxylates and other non-degradable water-soluble polymers. PASP one of poly (amino acid)s, possesses carboxylic acid pendant group in its repeating unit, which can be used for various further modification purposes. In this study we prepared high molecular weight polysuccinimide, as the precursor polymer for PASP, by thermal polycondensation ofL-aspartic acid in the presence of phosphoric acid. The polysuccinimide was hydrolyzed with 0.1 N sodium hydroxide, and then acidified to give PASP. High water-absorbent gels were produced by thermal crosslinking of freeze-dried mixture of partially-neutralized PASP and different amount of low moi. wt. PEG-diepoxide compounds in aqueous medium. The swelling behavior of the prepared gels from different size and composition of crosslinking reagent in different media was investigated and the results were discussed. This PASP-based hydrogel materials possessing inherent biodegradability, potential non-toxicity and biocompatibility, is expected to be used as a substrate for various biomedical applications as well as a general purpose super-absorbent polymer.

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Synthesis and Characterization of Three-dimensional Polymer Produced by Mutual Condensation of Ethylenediamine and $C_{60}$

  • Vovk, O.;Lee, Joong-Kee
    • Carbon letters
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    • v.5 no.2
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    • pp.68-74
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    • 2004
  • The polymer with contents of $C_{60}$ up to 57 wt.% was produced by mutual condensation of fullerene $C_{60}$ and ethylenediamine. The investigations of this polymer as well as pristine fullerene to comparison were carried out by FT-IR and UV-Vis spectroscopy, ToF-SIMS, TGA, and elemental analysis. At least three kinds of components was revealed as building blocks of polymer. The fullerene cage underwent only distortion but didn't destroy during formation of polymer. The pure fullerene was found as an intermediate of the thermal decomposition of polymer. The conclusion that this polymer could serve as precursor to produce carbon nanomaterial with high concentration curved graphene sheets and can be used for gas adsorption and electrochemical application was made.

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Fabrication of in-situ Formed Namo-Composite Using Polymer Precursor : I. Adsorption Behavior of Polymer Followed $SiO_2$ Surface formation onto Silicon Nitride Surface (폴리머 Precursor를 이용한 in-situ 나노 복합체의 제조 : I. 질화규소 표면에서의 $SiO_2$ 피막형성에 따른 폴리머의 흡착거동)

  • 정연길;백운규
    • Journal of the Korean Ceramic Society
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    • v.37 no.3
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    • pp.280-287
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    • 2000
  • Adsorption behavior and amount of phenolic resin followed silica (SiO2) formation onto silicon nitride(Si3N4) surface were investigated using electrokinetic sonic amplitude (ESA) technique and with UV spectrometer, to fabricate Si3N4/SiC nano-composite based on reaction between SiO2 formed and phenolic resin absorbed onto Si3N4 particle. The amount of SiO2 formed and carbon from phenolic resin absorbed onto Si3N4 surface were calculated quantitatively to adjust the reaction between SiO2 and phenolic resin, resulting in no residual SiO2 and carbon. As a result, pre-heated tempeature for optimized reaction was below 25$0^{\circ}C$, in which there was no residual SiO2 and carbon.

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Study on Preparation of PAHPV LB Films and Their Luminescent Characterisrics (PAHPV LB막의 제작 및 그 발광 특성에 관한 연구)

  • Hwang, Jang-Hwan;Choo, Jung-Woo;Kim, Young-Kwan;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.14 no.2
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    • pp.71-79
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    • 1997
  • Ultra-thin films of poly[2-[4-(9-(10-phenyl)anthracenyl)phenoxy)hexyloxy]]-1,4-phenylenevinyleylene(PAHPV) were prepare-d on the hydrophilic ITO substrate by Langmuir-Blodgett(LB) technique. ${\lambda}_{max}$ in the photoluminescence spectrum of these films was 458nm at the excitation wavelength of 365nm before thermal treatment, which comes from diphenylanthracene side chain of PAHPV. It was also confirmed with UV-Vis spectrometer that ultra-thin LB films of PAHPV precursor polymer were prepared well. After thermal treatment for conjugation of PAHPV precursor polymer, ${\lambda}_{max}$ in the photoluminescence spectrum of these films changed to 365nm, which means that the conjugation of these PAHPV films was completed.

Densification of 4D Carbon Fiber Performs with Mesophase Pitch as Matrix-Precursor

  • Joo, Hyeok-Jong;Lee, Jae-Won
    • Carbon letters
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    • v.6 no.3
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    • pp.173-180
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    • 2005
  • In this study, AR (aromatic resin) pitch was employed as the matrix-precursor for carbon/carbon composite because it exhibits much higher coke yield than coal tar pitch. As a result, a fabrication process of carbon/carbon composites can be shortened. It has been known that the pitches may cause swolling problem during the carbonization process. In order to restrain the swelling occurrence, a small quantity of carbon black was added to the AR pitch. Due to addition of carbon black the swelling was decreased largely and the perform can be infiltrated with the AR pitch. The densification efficiency of the performs was compared with various matrix-precursors. The coke yield of matrixprecursors, the morphology and the degree of graphitization of carbon matrix were analyzed.

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Synthesis and Their Properties of (0.8PPV+0.2DMPPV)/Silica Glass, Borosilicate Glass Composites by Sol-Gel Process (Sol-Gel법을 이용한 (0.8PPV+0.2DMPPV)/Silica Glass, Borosilicate Glass 복합체의 합성과 그 특성)

  • 이병우;김병호;윤영권;한원택
    • Journal of the Korean Ceramic Society
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    • v.34 no.9
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    • pp.993-1001
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    • 1997
  • The (0.8PPV+0.2DMPPV) copolymer and silica/borosilicate composites were synthesized by sol-gel process. The organic-inorganic hybrid solution was prepared by using of (0.8PPV+0.2DMPPV) copolymer precursor solution as a raw material for organic components and TEOS and TMB for glass components. Then by drying the solution in vacuum at 5$0^{\circ}C$ for 7days and subsequent heat treatment in vacuum at 15$0^{\circ}C$~30$0^{\circ}C$ for 2h~72h with heating rate of 0.2$^{\circ}C$/min and 1.8$^{\circ}C$/min, the organic-inorganic composites were synthesized. Microstructural evolution of the composites was characterized by DSC, IR spectrocopy, UV/VIS spectroscopy, and TEM. Elimination of the polymer precursor and degradation of the polymer were observed by DSC and Si-O and trans C=C absorption peaks were identified by IR spectra. The polymer was found to be successfully incorporated into the glass matrix and it was confirmed by the absorption peaks from the polymer in the UV/VIS spectra and the TEM results. The absorption peak of the composites was found to shift toward short wavelength side compared to that of the pure polymer and the amount of the blue shift increased with increasing the heat treatment temperature and heat treatment time and with decreasing the heating rate.

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Fabrication and Characterization of Zirconia-Alumina Composites by Organic-Inorganic Solution Technique (유기물-무기물 용액법을 이용한 지르코니아-알루미나 복합체의 제조 및 특성)

  • Kim, Youn Cheol;Bang, Moon-Soo;Lee, Sang Jin
    • Applied Chemistry for Engineering
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    • v.16 no.5
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    • pp.628-634
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    • 2005
  • Zirconia-alumina polymer precursor was prepared from zirconium acetylacetonate (ZA). paluminium nitrate (AN), polyethylene glycol (PEG), and ethyl alcohol via an organic-inorganic solution technique. The thermal properties and viscosity of the polymer precursor were measured by differential scanning calorimetry (DSC), thermograbimetric analyzer (TGA), and dynamic viscometer. The vigorous exothermic reaction with volume expansion occurred at $140^{\circ}C$. The volume expansion was caused by abrupt decomposition of the organic group in metal compounds and the metal ions-PEG reaction. The evidences for these reactions were confirmed by FT-IR and $^{13}C$ solid NMR results. The peak intensity at N-O, O-H and C=C decreased with increasing temperature. This indicated that the decomposition of metal compounds and the metal ions-PEG reaction occurred during the vigorous exothermic reaction. At $800^{\circ}C$ for 2 h, the porous powders transformed to the crystalline $ZrO_2-Al_2O_3$ composites.

Synthesis of Tri-armed Star Shaped Polymer of Acrylonitrile (아크릴로니트릴의 3가닥 별모양 고분자의 중합)

  • 신종호;한신호
    • Textile Science and Engineering
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    • v.31 no.2
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    • pp.89-95
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    • 1994
  • Polymerization of acrylonitrile(AN) was initiated by azobisisobutyronitrile(AIBN) in the presence of the polymerizable precursor. pentaerythritol triacrylate(PETA), synthesized from pentaerythritol(PETOL) and acrylic acid(AA). After the removal of gel portion from white powder-like precipitate, the molecular weight of polymer of soluble portion was measured by IR and GPC. Comparison in the molecular weight before and after the selective reduction of polymer ester group with ate complex revealed that the polymer obtained in this polymerization system is a sriarmed star shaped acrylonitrile polymer. Various reaction parameters affecting the structure of star shaped polymer were also discussed.

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Synthesis and characterization of negative-type photosensitive polyimides for TFT-LCD array

  • Kim, Hyo-Jin;Kim, Hyun-Suk;Kim, Soon-Hak;Park, Lee-Soon;Hur, Young-Hune;Lee, Yoon-Soo;Song, Gab-Deuk;Kwon, Young-Hwan
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1625-1628
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    • 2006
  • Two different negative-type photosensitive polyimides were synthesized and characterized for an application as an interdielectric layer in TFTLCD array. In the case of photocurable polyimides, the photosensitive moiety, 2-HHSP, was synthesized through 3 step reaction, and then was incorporated into side chains of polyimide precursor by post reaction. Optimum compositions of negative-type photocurable polyimde were also formulated. For photopolymerizable polyimides, two novel UV monomers containing imide linkages were prepared. An aqueous alkaline developable polymer matrix was synthesized by free radical copolymerization. A negative photoresist formulation was developed utilizing synthesized UV monomers containing imide linkage, photoinitiator, UV oligomer, and alkali developable polymer matrix. It was found that viaholes with good resolution, high transmittance and thermal resistance could be obtained by photolithographic process utilizing the negative-type photoresist formulations.

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