Aliphatic polyketones structure

Aliphatic polyketones are made from the reaction of olefin monomers and carbon monoxide using a variety of catalysts. Shell commercialized a terpolymer of carbon monoxide, ethylene, and a small amount of propylene in 1996 under the trade name Carilon (structure 4.79). They have a useful range between the Tg (15°C) and (200°C) that corresponds to the general useful range of temperatures for most industrial applications. The presence of polar groups causes the materials to be tough, with the starting materials readily available. 

The copolymerization of ethylene and carbon monoxide to give alternating copolymers has attracted considerable interest in both academia and industry over recent decades [1], Attention was focused on aliphatic polyketones such as poly(3-oxotrimethylene), (Structure 1) because of the low cost and plentiful availability of the simple monomers, ethylene and carbon monoxide. 

A unique catalyst invention at the Shell Research Laboratories in Amsterdam in 1982 [l, 2, 3] made it possible to polymerise carbon monoxide and alpha-olefins such as ethylene into linear, perfectly alternating structures. This led directly to the development of a new class of thermoplastic polymers known as aliphatic polyketones (PK), which Shell is commercialising under the trademark CARILON. 

The good tensile properties achievable with fibers made from PK-EP-6 make it an obviously attractive material for reinforcement in rubber applications, such as tires, hoses, and belts. In view of the inherent structure of aliphatic polyketones, which is vulnerable to photolytic attack if not adequately protected, direct exposure to sunlight should be limited, which is avoided in the case of rubber reinforcements. 

Aliphatic polyketones are still in an early phase of product development and at present, only terpolymers based on CO, ethene, and propene are in a well-enough advanced state of development for use as engineering thermoplastics. Future research into the structure-performance relationships of co- and terpolymers based on these and other olefinic monomers will lead to a controlled molecular tailoring and designing of polymers with desired properties. 

Made by catalytic polymerization of carbon monoxide and olefins into linear, alternating structures. Aliphatic polyketones are a new commercial class of semi-crystalline thermoplastics. Currently, of limited availability, but a larger product range is under development. 

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