Catalysis in Acyclic Diene Metathesis (ADMET) Polymerization - Late Transition Metal Polymerization Catalysis - page 200

Scheme 6.11 Olefin equilibration via trans -metathesis.
6.2.7
Applications of ADMET
ADMET has found a variety of applications, mostly based on the synthesis of nov-
el linear polymers. Generally speaking, ADMET is particularly useful for synthe-
sizing linear polymers with functionality or structure separated by a length of
methylene units and a carbon-carbon double bond [38-43], although conjugated
[44, 45] and other polymeric structures [46] have also been synthesized via AD-
MET. Comprehensive reviews exist in the literature [47, 48], so only a few exam-
ples of these polymers will be given here. Saturated polymers resulting from hy-
drogenation of the carbon-carbon double bonds of ADMET polymers are desirable
materials, and a very useful sequential one-pot homogeneous ADMET heteroge-
neous hydrogenation technique exists to perform this reduction [49].
Recently, much attention has been devoted to modeling polyolefins and copoly-
mers of ethylene and polar monomers. For example, polymers with regularly
spaced methyl groups on a polyethylene backbone have been synthesized and dis-
play very interesting and surprising thermal properties and microstructure [12].
This represents a rational synthesis of branched polyethylene that cannot be
achieved by any other means at this time (Scheme 6.12).
Scheme 6.12 Synthesis of ADMET polyethylene and ethylene-propylene copolymers.