Scholarlink

<p>The design of low-cost and high-performance cyclic olefin copolymers remains challenging. Ethylene copolymers with dicyclopentadiene (DCPD) were prepared using Ph<sub>2</sub>C(Cp)(Flu)ZrCl<sub>2</sub> (<b>Cat. 1</b>), <i>rac</i>-Et(Ind)2ZrCl<sub>2</sub> (<b>Cat. 2</b>), Me<sub>2</sub>C(Cp)(Flu)ZrCl<sub>2</sub> (<b>Cat. 3</b>) and Me<sub>2</sub>Si(Ind)<sub>2</sub>ZrCl<sub>2</sub> (<b>Cat. 4</b>) combined with [Ph<sub>3</sub>C][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>]/<sup><i>i</i></sup>Bu<sub>3</sub>Al. Ni(acac)<sub>2</sub>/<sup><i>i</i></sup>Bu<sub>3</sub>Al was then used to catalyze the hydrogenation of the intracyclic double bonds of ethylene/DCPD copolymers. The results showed that compared to <i>C</i><sub>2</sub> symmetric catalysts (<b>Cat. 2</b> and <b>Cat. 4</b>), <i>C</i><sub>s</sub> symmetric catalysts (<b>Cat. 1</b> and <b>Cat. 3</b>) facilitated the incorporation of copolymers with higher DCPD. <sup>1</sup>H-and <sup>13</sup>C-NMR spectra indicated that ethylene/DCPD copolymerization occurred via enhancement of the norbornene ring. Additionally, measurement of the reactivity ratios provided further confirmation that the copolymers had random sequence distributions. All these samples demonstrated transmittance values above 90% in the visible wavelength range from 400 nm to 800 nm. By changing the fraction of monomers, the glass transition temperature, refractive index, Young's modulus, and tensile strength of the copolymer increased as the incorporation of DCPD increased, whereas the Abbe number and elongation at break decreased. Compared with ethylene/norbornene and ethylene/tetracyclicdodecene copolymers, ethylene/DCPD copolymers, with excellent optical and mechanical properties, are promising materials.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Preparation and Hydrogenation of Dicyclopentadiene-based Cyclic Olefin Copolymers

  • 期刊论文

  • 发表日期：

    2025年6月4日

查看全文
  • Xiang-Han Zhang,
  • Xiao-Hui Mao,
  • Huan Gao,
  • Shui-Yuan Luo,
  • Zhe Ma,
  • Li Pan,
  • Yue-Sheng Li

摘要

The design of low-cost and high-performance cyclic olefin copolymers remains challenging. Ethylene copolymers with dicyclopentadiene (DCPD) were prepared using Ph2C(Cp)(Flu)ZrCl2 (Cat. 1), rac-Et(Ind)2ZrCl2 (Cat. 2), Me2C(Cp)(Flu)ZrCl2 (Cat. 3) and Me2Si(Ind)2ZrCl2 (Cat. 4) combined with [Ph3C][B(C6F5)4]/iBu3Al. Ni(acac)2/iBu3Al was then used to catalyze the hydrogenation of the intracyclic double bonds of ethylene/DCPD copolymers. The results showed that compared to C2 symmetric catalysts (Cat. 2 and Cat. 4), Cs symmetric catalysts (Cat. 1 and Cat. 3) facilitated the incorporation of copolymers with higher DCPD. 1H-and 13C-NMR spectra indicated that ethylene/DCPD copolymerization occurred via enhancement of the norbornene ring. Additionally, measurement of the reactivity ratios provided further confirmation that the copolymers had random sequence distributions. All these samples demonstrated transmittance values above 90% in the visible wavelength range from 400 nm to 800 nm. By changing the fraction of monomers, the glass transition temperature, refractive index, Young's modulus, and tensile strength of the copolymer increased as the incorporation of DCPD increased, whereas the Abbe number and elongation at break decreased. Compared with ethylene/norbornene and ethylene/tetracyclicdodecene copolymers, ethylene/DCPD copolymers, with excellent optical and mechanical properties, are promising materials.