Controlled Chain-Scission of Polybutadiene by the Schwartz Hydrozirconation
Controlled Chain-Scission of Polybutadiene by the Schwartz Hydrozirconation
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Schwartz 氢化锆化控制聚丁二烯断链
DOI：
10.1002/chem.201202942
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Tang Tao
中科院分区：
文献类型：
--
作者：
Zheng Jun;Lin Yichao;Liu Feng;Tan Haiying;Wang Yanhui;Tang Tao
Controlled chain‐scission of polybutadiene (PB), polyisoprene, and poly(styrene‐co‐butadiene), induced by bis(cyclopentadienyl) zirconium hydrochloride (Cp2ZrHCl), was revealed at room temperature. The chain‐scission reaction of linear PB was studied by means of GPC, NMR spectroscopy, and MALDI‐TOF‐MS. It was confirmed that the molecular weights of degraded products were quasi‐quantitatively controlled by Cp2ZrHCl loading, irrespective of the starting PB, whereas the microstructure of PB chains was crucial to the scission reaction. The hydrozirconation of model molecules indicated that the existence of an internal double bond in compounds with multiple double bonds was essential for chain cleavage. The chain‐cleavage mechanism was proposed to involve hydrozirconation of internal double bonds in PB chains and β‐alkyl elimination. Furthermore, metallocene‐catalyzed chain‐scission by a chain‐transfer reaction was developed. It is believed that the reported chain scission offers a promising pathway for end‐group functionalization by chain cleavage and presents a new application of Schwartz’s reagent.
