New lubricants containing star-shaped polymers have hit the market, thanks to Australian polymer technology. Lubrizol Corporation has launched the first commercial products developed using CSIRO’s Reversible Addition Fragmentation chain Transfer (RAFT) polymer synthesis process.

CSIRO chemist Dr Ezio Rizzardo says the RAFT process allows much greater flexibility and potential for polymer synthesis, compared with conventional methods. “Conventional polymerisation is a relatively simple process with two ingredients: large amounts of monomer and a small amount of an initiating agent. You apply heat; a chain reaction starts and runs to completion, making polymer chains that can have widely varying lengths.”

RAFT technology revolutionises polymer synthesis through the addition of a third ingredient—a “RAFT Agent”—that transforms the synthesis into a more controlled step-wise process.

“The RAFT Agent dictates the size of the chains and all the chains produced are a similar size. This gives the product unique properties,” says Ezio, who was joint winner of the 2011 Prime Minister’s Prize for Science for this research.

The RAFT process has been nicknamed “living polymerisation” because it can be stopped and restarted, and chains can be continued with different monomers. This provides unprecedented control over the composition and structure of new polymers, allowing specific chain lengths, branching and even polymers with complex architecture.

Star-shaped polymers—with arms that roll up at low temperatures and extend when warmed—improve the viscosity of Lubrizol’s lubricants, giving the vehicles that use them better performance and mileage.

Lubricants are just the beginning. RAFT technology is leading to a new generation of polymers in drug delivery systems, cosmetics, agrichemicals, solar cells and improved industrial chemicals.

Photo: Asteric ™ Viscosity Modifiers are tailor-made star-shaped polymers made possible by RAFT

Credit: Lubrizol

CSIRO Materials Science and Engineering, Ezio Rizzardo, +61 3 9545 2500,
ezio.rizzardo@csiro.au, www.csiro.au/en/Research/MF/Areas/Chemicals-and-fibres/Chemistry-and-biotechnology/RAFT