Precision design of novel bio-based and ethylene-based copolymers: application to advanced nanocomposites

Polyolefins are an inexpensive class of compounds that can be used to prepare a plethora of different materials. Poly(ethylene) is the worldwide most produced polymer and is mostly synthesised by free radical polymerisation or catalytic coordination insertion using high temperature and pressure. The controlled radical polymerisation of ethylene is very difficult to achieve because of secondary reactions of this unconjugated monomer, e.g. chain transfer and termination reactions. Cobalt-mediated radical polymerisation (CMRP) represents a solution to control its polymerisation in mild conditions: in a reversible deactivation mechanism, a cobalt complex reversibly traps the active growing chains and converts them into dormant species, avoiding side reactions and allowing for a controlled polymerisation. Using CMRP, statistical copolymers of ethylene and vinyl acetate (VAc) have been synthesised, as well as block-like and block copolymers. Furthermore, functionalisation of the α- and ω-chain ends are now possible. Polymerising a vinyl bio-based monomer using CMRP has also been investigated, with the goal of forming ethylene copolymers. The copolymerisation behaviour of this novel monomer was investigated using vinyl acetate as a model and the structure and thermal properties were analysed. The monomer is very promising and copolymerisations with ethylene are undergoing. It is expected, that these completely new and highly interesting materials may act as compatibilisers for the dispersion of natural polymers, such as cellulose, into various polymer matrices.