Novel property and application of polyolefin stem from precise control of its structure and composition. Polymethylene(polyethylene's analogue) and its copolymers have become one of hot topics of current research in the polyolefin functionalization field in recent years. In this review, firstly, the polyhomologation of ylide leading to linear polymethylenes with controllable molecular weight and narrow molecular weight distribution is introduced briefly. Then, various borane initiators and ylide monomers used for polyhomologation are described in detail. In addition, the controllable syntheses of new polymethylene-based copolymers by combining polyhomologation with ring-opening polymerization, atom transfer radical polymerization, reversible addition-fragmentation chain transfer polymerization, nitroxide mediated polymerization, ionic polymerization, ring-opening metathesis polymerization and coupling reactions, are reviewed. Finally, the future development of the controllable synthesis strategies and practical application of new polymethylene-based copolymers are prospected.
Contents
1 Introduction
2 Initiators of polyhomologation
2.1 Trifunctional organoboranes
2.2 Bifunctional organoboranes
2.3 Monofunctional organoboranes
3 Monomers of polyhomologation
3.1 Sulfur ylides
3.2 Arsenic ylides
4 Combination with other methodologies to prepare polymethylene-based copolymers
4.1 Combination with ring-opening polymerization
4.2 Combination with atom transfer radical polymerization
4.3 Combination with reversible addition-fragmentation chain transfer polymerization
4.4 Combination with nitroxide-mediated radical polymerization
4.5 Combination with ionic polymerization
4.6 Combination with ring-opening metathesis polymerization
4.7 Combination with coupling reaction
5 Conclusion and outlook