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Professor Zhang Xinghong's group at Zhejiang University has made progress in the research of selenium-rich polymer synthesis
2019-12-24 Source: Polymer Technology

Selenium (Se) is a semi-metallic element, located in the sixth main group of the periodic table, and has similar chemical properties to sulfur. Compared with sulfur atom, selenium atom has lower electronegativity and larger atomic radius. These characteristics give selenium high chemical reactivity. The selenium-containing polymer material is a functional material, which has a variety of potential applications in responsive and biomedical materials, which has attracted widespread interest from researchers. Professor Xu Huaping's group from Tsinghua University has made outstanding contributions in the synthesis and application of selenium-containing polymers. So far, few reports on the synthesis of selenium-enriched polymers with controllable structure have been reported.

figure 1

Recently, Professor Zhang Xinghong's group at Zhejiang University realized the synthesis of selenium-containing polyester for the first time by alternating copolymerization of epoxy monomer and γ- selenobutyrolactone (Figure 1). The author used biomass γ-butyrolactone as a raw material, and obtained γ-selenobutyrolactone by a two-step reaction with reference to literature methods. However, unlike γ-butyrolactone, experiments have shown that ring-opening polymerization of γ-selenobutyrolactone is very difficult (? 40 ~ 100 ° C, organic base), mainly because γ-selenobutyrolactone has a lower Ring tension. They used epoxy monomers with high ring tension to copolymerize γ-selenobutyrolactone, and used organic bases as catalysts to achieve ring-opening polymerization of γ-selenobutyrolactone at room temperature. The copolymerization has nearly perfect alternating copolymerization and regioselective reaction characteristics: the degree of alternation of the obtained selenium-containing polyester is> 99%, and the content of the head and tail structure is> 99%, and the "on-off" copolymerization can be achieved by controlling the amount of monomer . Each segment of the obtained selenium-containing polyester contains common ester bonds and Se ether bonds, and the terminal groups are controllable. Selenium-containing polyesters with hydroxyl groups at both ends can be obtained, and selenium-containing high Se-Se bonds can also be obtained. molecule. 6 S/cm,30 °C;1.73 × 10 ?4 S/cm,100 °C),表明这些材料具有潜在的广阔应用前景。 The obtained selenium-containing polyester has good thermal properties. Its initial thermal decomposition temperature is as high as 275 ° C, and its glass transition temperature is as low as -59 ° C. It is soluble in common organic solvents. The selenium-containing polyester has a high refractive index (1.61 ? 1.62) and good ionic conductivity (doped lithium salt, 1.09 × 10 ? 6 S / cm, 30 ° C; 1.73 × 10 ? 4 S / cm, 100 ° C), indicating that these materials have potential broad applications prospect.

The above related results were published in Macromolecules (DOI: 10.1021 / acs.macromol.9b02025). The first author of the article is doctoral student Zhang Chengjian , and the corresponding author is Professor Zhang Xinghong .

Article related links: http://pubs.acs.org/doi/abs/10.1021/acs.macromol.9b02025

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