A kind of hydrogenated styrene diene copolymer viscosity index improver and preparation method thereof

Abstract

The invention relates to a viscosity index improver for a hydrogenated styrene-diene copolymer and a preparation method thereof. The copolymer is a hydrogenated star polymer; and at least 95% of the unsaturated double bonds of diolefin are hydrogenated, and at most 10% of the unsaturated bonds of aromatic hydrocarbon are hydrogenated. The polymer has the following characteristics before hydrogenation: the core of the polymer is a poly(divinylbenzene) residue; the arms of the polymer are two-block copolymers, and a block I is an isoprene-butadiene copolymer while a block II is polystyrene; the number of the arms is 3; single-arm molecular weight is 20, 000 to 100, 000; and the contents of polystyrene, polyisoprene and polybutadiene by mass are 2 to 15%, 30 to 90% and 5 to 60%, respectively. The improver has excellent thickening capability, shearing stability and soot dispersibility.

Description

technical field

[0001] The invention relates to an oil-soluble polymer which can be used as a viscosity index improver, especially the polymer has the properties of a viscosity index improver and a dispersant. Background technique

[0002] With the advancement of automobile engine technology, the requirements for engine oil are becoming more and more stringent. Especially with the adoption of some new technologies, such as fuel delayed injection technology, turbocharging technology, exhaust gas recirculation technology, etc., more and more soot will be produced during the combustion process of fuel. The lubricating effect of the oil will deteriorate rapidly, resulting in a significant reduction in the service life of the oil, which not only increases the burden on consumers, but may also cause damage to the engine in severe cases. There are usually two ways to solve the above problems: one is to add a dispersant to the engine oil to disperse the soot; the other is to add an...

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