• 제목/요약/키워드: Polymer processing

검색결과 628건 처리시간 0.027초

Crystallization Vitrification and Phase Separation

  • Kim, Sung-Chul
    • 유변학
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    • 제1권1호
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    • pp.12-19
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    • 1989
  • Polymer fluid flow and polymerization reaction occur simultaneously during the reactive polymer processing. The viscosity and physical properties change as thereaction proceeds and the crystallization and vitrifica-tion occur as the T,,,and the Tg of the polymerizing fluid exceeds the reaction temperature within the mold.

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Novel Processing Technology of Nanocomposites Using supercritical fluid

  • Hong, Young-Ki;Lee, Hyun-Jung;Lee, Sang-Soo;Park, Min;Kim, Jun-Kyung;Lim, Soon-Ho
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.215-215
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    • 2006
  • The cyclic butylene terephthalte oligomer was synthesized and the composition of butylenes terephthalate cyclic oligomers was 51.2 % of dimer, 28.1 % of trimer, 7.9 % of tetramer, 8 % of pentamer and 4.8% of hexamer. Polybuthylene terephthalate was polymerized using this cyclic oligomer in the condition of melt process and supercritical process. And PBT/clay nanocomposite were manu- factured from melt process and supercritical process. Chlorodifluoro- methane(HCFC-22) was used as a solvent which has critical point ($Tc=96.2^{\circ}C$, Pc=49.7bar). Also polymer nanocomposite were manufactured using rapid expansion of supercritical solution process.

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Effect of Surfactant on the Physical Properties and Crosslink Density of Silica Filled ESBR Compounds and Carbon Black Filled Compounds

  • Hwang, Kiwon;Kim, Woong;Ahn, Byungkyu;Mun, Hyunsung;Yu, Eunho;Kim, Donghyuk;Ryu, Gyeongchan;Kim, Wonho
    • Elastomers and Composites
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    • 제53권2호
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    • pp.39-47
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    • 2018
  • Styrene-butadiene rubber (SBR) is widely used in tire treads due to its excellent abrasion resistance, braking performance, and reasonable cost. Depending on the polymerization method, SBR is classified into solution-polymerized SBR (SSBR) and emulsion-polymerized SBR (ESBR). ESBR is less expensive and environmentally friendlier than SSBR because it uses water as a solvent. A higher molecular weight is also easier to obtain in ESBR, which has advantages in mechanical properties and tire performance. In ESBR polymerization, a surfactant is added to create an emulsion system with a hydrophobic monomer in the water phase. However, some amount of surfactant remains in the ESBR during coagulation, making the polymer chains in micelles clump together. As a result, it is well-known that residual surfactant adversely affects the physical properties of silica-filled ESBR compounds. However, researches about the effect of residual surfactant on the physical properties of ESBR are lacking. Therefore, in this study we compared the effects of remaining surfactant in ESBR on the mechanical properties of silica-filled and carbon black-filled compounds. The crosslinking density and filler-rubber interaction are also analyzed by using the Flory-Rehner theory and Kraus equation. In addition, the effects of surfactant on the mechanical properties and crosslinking density are compared with the effects of TDAE oil (a conventional processing aid).