DISPERSANT AND NON-DISPERSANT COMB POLYMERS - BUILDING BLOCKS IN YOUR PORTFOLIO FOR DRIVELINE FUEL ECONOMY
Optimizing fuel economy requires constant improvements in lubricant
performance. Due to its multiple modes of action, the viscosity modifier
has become a crucial design element for fuel economy. Poly(alkyl
methacrylates) are the predominant viscosity modifiers in driveline
lubricants. This chemistry has been combined with polyolefins to create
defined comb polymers that allow for significantly reduced low
temperature viscosity which directly translates to fuel economy. This
paper showcases the fuel economy advantages in NEDC and JC08
cycles for automatic transmission fluids formulated with combs. The
comb polymer chemistry has now been upgraded with add-on
performance based on nitrogen- and oxygen-functional ‘dispersant’
moieties. This new generation of dispersant comb polymers provides
an expanded performance envelope that comprises not only superior
viscometrics but also improved high-µ wet clutch friction, dispersancy
of oxidation products as well as increased pitting life-time.