1A substance that propels something.

1. 1.1 An inert fluid, liquefied under pressure, in which the active contents of an aerosol are dispersed.
   the main uses of CFCs are in aerosols as propellants

   mass noun aerosols are wastefully packaged, because they contain a lot of propellant as well as the product

   Example sentencesExamples

   • The other thing our government needed to protect us from was the stuff used as propellant in aerosol cans.
   • CFCs had been used commercially as refrigerants since the 1930s, but because they were inert and non-poisonous they were soon used for many other applications, most notably as propellants in aerosol spray cans.
   • Alternatively, the aerosol container may be inverted allowing direct access to the propellant via the dip tube.
   • These metal cans are capped with valves that seal the pressurized propellant in the can and control dispensing of the contents.
   • Aerosol propellants contain flammable and nerve-damaging ingredients as well as tiny particles that can lodge in your lungs.
   • They have uses as propellants in aerosol spray cans, refrigerant gases, and foaming agents for blown plastics.
   • In automobiles, for example, the thermal decomposition of sodium azide produces a large amount of nitrogen gas that acts as a propellant that causes air bags to open on impact.
   • This gas has long been used as a propellant in aerosol sprays and in refrigerators.
   • For example, chlorofluorocarbons have been used in the second half of the 20th century as nonflammable refrigerants, industrial solvents, foaming agents, and aerosol propellants.
   • He explained that deodorants and other aerosols contain propellants, like butane, to dry the particles.
   • They include ether, chloroform and halothane; the ones that commonly cause addiction are ethyl alcohol, propellants in spray cans and petrol.
   • These inhalers don't use a chemical propellant to push the medication out of the inhaler.
   • Chlorofluorocarbons were developed and used as refrigerants, blowing agents for polyurethane foam, and propellants in spray cans.
   • Carbon dioxide is used to make carbonated beverages, in fire extinguishers, and as a propellant in aerosol products.
   • In the 1970s, the United States, along with several other countries, banned the use of CFCs as aerosol propellants.
   • The data on whether the majority of cancers, neurological problems, and other health problems are associated with exposure to fuels, propellants, or combustion products were inadequate to draw conclusions.
   • Today, almost all aerosol cans contain alternative propellants, such as liquefied petroleum gas, which do not pose as serious a threat to the environment.
   • By the mid-1970s, the United States government banned the use of CFCs as aerosol propellants but it resisted a total ban for all industries.
   • These substances, also known as freons, were once used extensively as coolant fluids in refrigerators and air conditioners, and as propellants in aerosol cans.
2. 1.2 An explosive that fires bullets from a firearm.
   the common gun propellants are either nitrocellulose or a mixture of nitrocellulose and nitroglycerine

   mass noun the company produced all sizes of propellant for weapons

   Example sentencesExamples

   • Many of the wars in this century were fought with TNT as the main explosive and with gunpowder as the main propellant of bullets and artillery shells.
   • However, the use of this explosive mixture of saltpetre, charcoal, and sulphur as a propellant for bullets from firearms, and thus gun powder, is a western development and one which took place gradually from the 13th century.
   • Smokeless propellants are expensive and not often used in making fireworks.
   • Liquid propellants clearly have the edge over gunpowder for military applications such as this.
   • It is necessary that all Field Artillery officers understand the different types of propellants, projectiles, fuzes, and their proper use, so that we can supervise our subordinates.
   • When the firing pin strikes the primer, it ignites the propellant.
   • The rapidly expanding gases from the burning propellant force the projectile through the cannon tube.
   • And we'll be doing some testing, including small-scale weapons testing, just to see how these propellants react in a gun environment.
   • In low explosives, such as the propellant in a bullet cartridge, the reaction occurs relatively slowly and the pressure isn't as damaging.
   • The parent companies are aiming to create a leading propellants and explosives company in Europe, drawing on advanced technologies and in-depth knowledge of this business.
   • The finding would be consistent with the plant's stated production capabilities in the field of basic raw materials for explosives and propellants.
   • Pyrotechnics came to Europe in the thirteenth century, where they quickly revolutionized warfare with their use as propellants in cannons and rockets, and in 1677, miners applied the science to blasting rock for the first time.
   • Of course, the scanner could only detect metals, energy sources and chemical compounds that could be combined into propellants and explosives.
   • Many centuries ago the Chinese first employed crude rockets using solidified propellants to scare their enemies with the resulting loud noises and flashing overhead lights.
   • When smokeless propellants were safely ensconced in society, what did they do with the .45 Colt?
   • To fire the weapon a projectile containing the propellant and explosive is dropped into the muzzle.
   • Black powder loading, though simple, requires different techniques than those used with smokeless propellants.
   • The rapid expansion of gases caused by the burning propellant propels the projectile from the tube toward the target.
   • By definition, explosive ordnance is any munitions, weapon delivery system, or ordnance item that contains explosives, propellants, and chemical agents.
3. 1.3 A substance used as a reagent in a rocket engine to provide thrust.
   rocket propellants

   Example sentencesExamples

   • When the propellants combine within the engine, they produce thrust.
   • To get to the Moon she expended only about 60 kilograms of xenon propellant.
   • A fixed amount of propellant is contained in the rocket motor.
   • The end result is a total of 108 tonnes of methane/oxygen rocket propellant.
   • The first rockets used solid propellants, such as black powder, but they were very inefficient.
   • Most NASA spacecraft rely on some form of chemical propellant to push themselves through space.
   • The maneuver is necessary, since onboard propellant is nearly depleted.
   • A pedant or two might ask if you really mean rocket propellants when you say rocket fuel.
   • Most launch vehicles use liquid propellants, but some use motors with solid fuels.
   • More like rocket engines, jets produce thrust by burning propellant (jet fuel mixed with air) and forcing the rapidly expanding gases rearward.
   • Rocket propellants come in two parts, fuel and oxidizer, which work together to keep an engine burning.
   • Perchlorate is a waterborne contaminant left over from propellants and rocket fuels.
   • Slower burning powders tend to deliver better accuracy than faster burning propellants, even when velocities are identical.
   • They therefore deliver about ten times as much thrust per kilogram of propellant used, making them very ‘fuel-efficient’.
   • He also theorized that liquid propellant made for a far more powerful and efficient fuel for rockets than solid propellant.
   • The long-planned impact is necessary now that the onboard propellant is nearly depleted.
   • The extra propellant provides an additional 50 tonnes of thrust in the first 20 seconds following liftoff.
   • My husband was a research chemist working on propellants - a real rocket scientist.
   • Perchlorate is the primary ingredient of solid rocket propellant that is increasingly found in soil and water.
   • The exhaust from an ion engine travels up to 10 times faster than does the exhaust from a chemical engine, generating far more thrust per pound of propellant.

   Synonyms

   power source, heat source, combustible

Capable of propelling something.