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A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes
Published on: February 27, 2017
Synthesis of high cis-1,4 polybutadiene with narrow molecular weight distribution via a neodymium-based binary
Jie Liu1, Xiaodong Fan1, Xin Min1
1The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University Xi'an 710072 P. R. China xfand@126.com.
Abstract:
This work explores the synthesis of polybutadiene (PB) with high cis-1,4 unit content and narrow molecular weight distribution using a neodymium-based complex, consisting of neodymium(iii) trifluoromethane sulfonate (Nd(CF3SO3)3) and coordinated with tris(2-ethylhexyl)phosphate (TOP). The complex's composition and structure are characterized by elemental analysis, XPS and FT-IR. Combined with Al(i-Bu)3, a binary catalyst is obtained and then applied to initiate the polymerization of butadiene. Results indicate that the catalyst system displays a high catalyst activity and the product polymer (PB) features a high cis-1,4 content (98.8%) and a remarkably narrow molecular weight distribution (M w/M n = 1.32). Compared with PB initiated by the current well-studied catalyst Nd(CF3SO3)3*3TBP/Al(i-Bu)3, the Nd(CF3SO3)3*3TOP allows significantly narrowing the molecular weight distribution of the PB, because the Nd(CF3SO3)3*3TOP is more easily dissolved in hexane. Therefore, butadiene was polymerized in a homogenous system and each monomer's polymerization was initiated in the single molecular state.
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