What Does A Viscosity Improver Do? 

What Does A Viscosity Improver Do? 


Viscosity improvers, also known as pour point depressants or flow improvers are chemical additives used in various industries to enhance the performance of fluids. These additives play a crucial role in maintaining the desired fluid properties under different operating conditions, ensuring efficient and reliable system operation. In this article, we will explore what viscosity improver does, its types, applications, and benefits.

What is viscosity?

Before delving into the specifics of viscosity improvers, it’s essential to understand the concept of viscosity. Viscosity refers to a fluid’s resistance to flow or deformation under stress. It measures how much force is required to move one layer of fluid relative to another adjacent layer. The unit of measurement for viscosity is typically centipoise (cP) or poise (P). Fluids with high viscosities require more force to flow than those with low viscosities.

Understanding viscosity improvers:

Viscosity improvers are polymeric molecules added to liquids to increase their apparent viscosity without significantly affecting other physical properties. They work by increasing the interaction between fluid layers, reducing turbulence, and improving flow characteristics. Viscosity improvers can be synthetic or natural polymers derived from petroleum, cellulosic, or other sources.

Types of viscosity improvers:

There are several types of viscosity improvers available, each with unique properties and applications. Some common varieties include:

  • Olefin copolymers: Synthetic polymers made from ethylene and propylene that provide excellent shear stability and temperature performance.
  • Polyisobutylene succinimides: A type of oil-soluble resin used in lubricating oils and fuels to improve viscosity index and pour point.
  • Styrene-butadiene rubbers: Synthetic rubbers used in automotive gear oils, hydraulic fluids, and industrial oils to enhance viscosity index and reduce pumping costs.
  • Cellulosics: Natural polymers derived from wood pulp or cotton fibers used in fuel and lubricant applications to prevent wax crystallization at low temperatures.
  • Acrylic polymers: Synthetic polymers used in engine oils, automatic transmission fluids, and greases to improve viscosity index and cold start performance.

Applications of viscosity improvers:

Viscosity improvers have numerous applications across various industries, including:

  • Automotive industry: Used in motor oils, gear oils, and transmission fluids to maintain consistent viscosity levels, ensure proper lubrication, and extend equipment life.
  • Industrial applications: Employed in hydraulic fluids, compressor oils, and metalworking fluids to optimize flow characteristics and reduce energy consumption.
  • Fuels: Added to diesel, jet fuel, and biofuels to lower pour points, minimize filter plugging, and improve cold weather performance.