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Your search keyword '"Zhang, Xing-Hong"' showing total 21 results
Start Over Author "Zhang, Xing-Hong" Journal macromolecules
21 results on '"Zhang, Xing-Hong"'

11. Chemoselective Coupling of CS2and Epoxides for Producing Poly(thioether)s and COS via Oxygen/Sulfur Atom Exchange

Author

Zhang, Cheng-Jian and Zhang, Xing-Hong

Abstract

Utilization of carbon disulfide (CS2), a low-cost and sulfur-rich one-carbon (C1) feedstock, for making sulfur-containing polymers is important for both polymer chemistry and applied environmental science. However, the production of well-defined sulfur-containing polymers from CS2and epoxides remains a key challenge. Here, we report a robust coupling reaction of CS2and epoxides for chemoselectively producing poly(thioether)s and carbonyl sulfide (COS) in one pot. The resultant polymer has exclusive thioether units and a thiol (−SH) terminal. This route takes advantage of oxygen/sulfur exchanges through two consecutive reactions, i.e., cycloaddition of CS2to epoxides and dethiocarboxylative ring-opening polymerization of the generated cyclic dithiocarbonates. The process can be conducted in ambient air with several commercially available organic bases as catalysts (initiators) and extended to a variety of epoxides, yielding COS and diverse poly(thioether)s with tens of grams. This work furnishes an original and practical strategy for utilizing CS2as a sulfur feedstock in polymer synthesis.

Published
2020
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20. Regioselective and Alternating Copolymerization ofCarbonyl Sulfide with Racemic Propylene Oxide.

Author

Luo, Ming, Zhang, Xing-Hong, Du, Bin-Yang, Wang, Qi, and Fan, Zhi-Qiang

Subjects
*REGIOSELECTIVITY (Chemistry), *COPOLYMERIZATION, *CARBONYL compounds, *PROPYLENE oxide, *MONOMERS, *REFRACTIVE index
Abstract

Wereport the first example of a regioregular and fully alternatingpoly (propylene monothiocarbonate) (PPMTC) from the well-controlledcopolymerization of two asymmetric monomers, carbonyl sulfide andracemic propylene oxide, using (Salen)CrCl in conjunction with bis(triphenylphosphoranylidene)ammoniumchloride. The maximum turnover of frequency of this catalyst systemwas 332 h–1at 25 °C. The contents of monothiocarbonateand tail-to-head linkages of PPMTC were up to 100% (based on 1H NMR spectra) and 99.0% (based on 13C NMR spectra),respectively. PPMTC samples have number-average molecular weight (Mn) up to 25.3 kg/mol with polydispersity indexof 1.41. The very low decomposition temperature of 137 °C andhigh refractive index of 1.63 of PPMTC make it a potential scarifyingoptical adhesive. [ABSTRACT FROM AUTHOR]

Published
2013
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