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Realistic Representation of Kinetics and Microstructure Development During Chain Shuttling Polymerization of Olefin Block Copolymers
Author(s) -
Ahmadi Mostafa,
Nasresfahani Amin
Publication year - 2015
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.201500004
Subject(s) - comonomer , copolymer , kinetics , materials science , chain transfer , polymerization , olefin fiber , microstructure , representation (politics) , chain (unit) , polymer chemistry , chemical engineering , radical polymerization , polymer , composite material , physics , astronomy , politics , political science , law , engineering , quantum mechanics
Olefin block copolymers (OBCs) are new class of thermoplastic elastomers having low glass transition temperature soft blocks and highly crystalline hard blocks synthesized by reversible chain shuttling between two catalysts with considerably different comonomer responses through a chain transfer agent. Theoretical representation of kinetics and microstructure evolution in chain shuttling polymerization (CSP) is of vital importance especially since the existing characterization tools have severe limitations in retrieving the blocky nature of OBCs. In this work, we correspondingly develop an effective model to represent CSP in practical conditions and compare our predictions to the existing experimental data. We illuminate kinetics and microstructure development in both OBC chains and individual blocks. We specifically clarify the effect of varying the reversibility of transfer reactions through tuning chain shuttling agent and hydrogen concentrations on OBC chains and blocks in terms of their corresponding molecular weight and chemical composition distribution and draw guidelines for achieving OBCs with desired properties.