Direct Synthesis of Polar Functionalized Polyethylene Thermoplastic Elastomer

Thermoplastic
elastomers (TPE) can be easily molded, extruded, and reused like plastics
and exhibit typical elastic properties like rubbers. They are widely
used in the automotive sector and household appliances sector. The
synthesis of thermoplastic polyolefin elastomers using only ethylene
as feedstock in a single step is a fascinating concept. The synthesis
of polyethylene thermoplastic elastomers through α-diimine nickel
catalyzed ethylene polymerization has been successfully achieved in
recent years. However, the utilization of α-diimine palladium
catalysts for this purpose is much more challenging due to their greater
chain-walking tendency versus the nickel counterpart, thereby leading
to the formation of highly branched polyolefins with poor mechanical
properties. In this contribution, we report the direct synthesis of
polyethylene thermoplastic elastomers through α-diimine palladium
catalyzed ethylene polymerization. With exquisite catalyst design
and polymerization regulation, polyethylene thermoplastic elastomers
with great mechanical and elastic properties can be obtained. Most
importantly, polar functionalized polyethylene thermoplastic elastomers
bearing great elastic properties can be generated through copolymerization
of ethylene with biomass-derived comonomers.