Article
  • Cationic Copolymerization of 1- and 2-Vinylnaphthalenes with α-Methylstyrene
  • Oh ST, Lee H, Cho WJ
  • 1- 및 2-Vinylnaphthalene과 α-Methylstyrene의 양이온 공중합에 관한 연구
  • 오상택, 이홍, 조원제
Abstract
The cationic copolymerizations of 1- and 2-vinylnaphthalenes with α-methylstyrene were carried out with titanium as an initiator in dichloromethane at various temperatures. The monomer reactivity ratios, r1 and r2, and the values of activation enthalpy and entropy differences have been determined. In the relationship between in ln r and 1/T, the ln r1 was proportional to 1/T but ln r2 was markedly decreased above -60℃ for 1-vinylnaphthalene and α-methylstyrene system. For 2-vinylnaphthalene and α-methylstyrene system, the ln r1 and r2 were proportional to 1/T. It were found that the reactivity of α-methylstyrene to 1- and 2-vinylnaphthalene and cations was greater than that of styrene and the reactivity of 2-vinylnaphthalene to α-methylstyryl cation was greater than that of 1-vinylnaphthalene at -75 and -60℃. The steric effect of methyl group in α-methylstyrene appears to be less important than the inductive effect and the peri-hydrogen effect in 1-vinylnaphthalene appears to be more important than the effect of π-conjugation of 1-naphthyl group. From the values of activation enthalpy (ΔH*)and entropy (ΔS*) differences, we can deduce that the copolymerizations of 1-and 2-vinylnaphthalene to α-methylstyryl cation are enthalpic controlled reaction at -75and -60℃ and entropic controlled reaction above -50℃.

Keywords:

  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2023 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 1986; 10(7): 699-707

    Published online Dec 25, 1986

  • 10.7317/pk.
  • Received on Nov 30, -0001
  • Revised on Nov 30, -0001
  • Accepted on Nov 30, -0001

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