Functionalised olefins copolymerisation

Though important results have already been obtained in the carbonylation of olefins, the field still remains open. Development of more active, efficient and stable catalysts based also on less expensive metals will make the carbonylation processes more attractive. Carbonylation of less common olefins, including functionalised ones, has to be explored in more depth. Other important targets are the efficient living copolymerisation, the multiple olefin insertion producing non-alternating copolymers and the selective synthesis of unsaturated products like acrylates and methacrylates. 

The discovery in the early 1980s that cationic palladium-phosphine complexes catalyse the copolymerisation of carbon monoxide with ethene or a higher a-olefin to yield perfectly alternating polyketones has since attracted continuous increasing interest [1,2]. This is because the monomers are produced in large amounts at a low cost and because polyketones represent a new class of thermoplastics of physical-mechanical and chemical properties that have wide applications [3-6]. In addition, easy functionalisation can open the way to a large number of new materials [7]. The copolymerisation has... 

In general, there are two ways to functionalise polyolefins via direct copolymerisation of an olefin with a polar monomer and via chemical modification of preformed polymers [508 514]. 

Coordination Homopolymerisation and Copolymerisation of Functionalised a-Olefins with Ethylene and a-Olefins... 

Functionalised a-olefins capable of undergoing insertion polymerisation with Ziegler-Natta catalysts are, in principle, monomers in which the heteroatom (X) does not electronically interact with the double bond to be polymerised in such monomers, the heteroatom is separated from the double bond CH2=CH-(CH2)x X [326,384,518,522-528], Monomers with the heteroatom directly bound to the double bond, i.e. those of the CH2=CH-X type, may also undergo polymerization, but when the heteroatom is silicon or tin (X= Si, Sn) [522-526], Representative examples of the insertion polymerisation of functionalised a-olefins and their copolymerisation with ethylene and a-olefins in the presence of heterogeneous Ziegler-Natta catalysts are shown in Table 3.7 [2,241,326,384,518,522-528],... 

Table 3.7 Insertion homopolymerisation and copolymerisation of functionalised a-olefins with ethylene and a-olefins in the presence of heterogeneous Ziegler-Natta catalysts...

Functionalised PO as block and graft copolymers used as compatibilisers or to increase interactions with other materials are prepared by free radical grafting (the simplest method), metallocene-catalysed copolymerisation of olefins with functional monomers, or anionic polymerisation (silane-containing PO). They are also produced by controlled/living polymerisation techniques such as nitroxide-mediated controlled radical polymerisation, atom transfer radical polymerisation (ATRP), and reversible addition-fragmentation chain transfer (RAFT). 

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