Hydroxy Terminated Polybutadiene

Propellant is a Rocket Feul, Propellant is chemicals for energy and pressurize production of gas, it used to produce vehicle propulsion orcreate fluid motions. Common propellants are energetic materials and consist of fuel, such as gasoline, jet fuel, rocket fuel, and oxidizing agents. Propellant decomposed to produce gas. Generally the propellant is an energetic material and consists of fuel of oxidizing agents.

An explanation of chemical, the combustion reaction occur if there was a fuel , oxidizer and ignitor (fire ignition). a material called as propellant if it consists of fuel and oxidizer. Chemically, propellant divided to three groups, solid, liquid and hybrid propellant.

The composite of solid propellant prepared from result polymerization reaction of Hydroxy Terminated Polybutadiene prepolymers and Isophorone Diisocyanate which form liquid (ful-binders). Then both materials mixed with Ammonium Perchlorate Oxide and Aluminum Additive Powder. The performance of propellant shown by specific impul and result of combustion speed.

Liquid propellant is a rocket engine in liquid form. High density of propellant allows the relatively of low tank volume, and possible to use of mild centrifugal turbopumps to pump propellant from the tank to combustion chamber, which means the propellant can be kept under low pressure then it allows to use of low propellant tank mass and produce high ratio.

The solid propellant fire generally whitish of color and accompanied by lot of concentrated smoke and the fire of liquid propellant rocket usually look light blue such as a fire on gas stove and doesno't produce much smoke.

The fuel of solid propellants is aluminum, it is not harmful for human health directly, but the smoke produced by rocket contains Hydrogen Chloride which capable of triggering acid rain that can cause crops and environment be damaged. The relationship between alumnium and acid rain we can see from this reaction.

2Al₂O₃  + 2OH^- -> AlO_2- + H₂O

but we will continue about "Acid Rain" in other post"

Rocket and Baking Soda

source

The rocket engine have a similar work with jet engines, the principal both rely on propulsion system (thrust) caused by propeller or propulsion. The propulsion system is a direct burning of rocket fuel results. Jet engines are categorized into several type, turbofan,turboshaft, and turbo jet. Those all called also turbine gas.

The working principle is simple, the air is in compress, then burned, and the result is expansed by the turbine. Furthermore, this turbine will produce a thrust force, it can also be connected to the turbofan and turbofan gearbox and then gearbox is connected to the propeller (turboprop), for the shaft is not much different from the turboprop.

The tendency of turbofan thrust force is greater than turbine expansion. The thrust force of turboprop expansion is less than propellant thrust, and the turbojet thrust is pure force of turbine expansion. Rocket engine hasn't turbine/blades that commonly found in turbine engines. The use of rocket propellant fuel generally a hydroxy terminated polybutadiene composite with ammonium perchlorate oxide, hydrogen peroxide, hydrogen gas and conventional fuel.

The simple science experiments for propellant materials using existing materials and simple equipment around us, by utilizing a bottles made from propellant from baking soda and vinegar.

People known the baking soda is a developer of bread dough or chemically called sodium bicarbonate (NaHCO₃). NaHCO₃ is produced from byproducts of Solvay process. we can write Solvay reaction equation as follow :

CO₂ + 2NaOH → Na₂CO₃ + H₂O

The addition of carbon dioxide to produce sodium bicarbonate, at high concentrations will be speed up the results.

Na₂CO₃ + CO₂ + H₂O → 2NaHCO₃ (s)

In this reaction sodium bicarbonate precipitates as a solid of this method. It also can be made from ammonia solution, the reaction of kitchen salt and carbon dioxide will produce ammonium chloride and sodium bicarbonate as byproducts.

Using Ammonia

NH₃ + CO₂ + NaCl + H₂O → NH₄Cl + NaHCO₃

Using Kitchen Salt.

2NaCl + CaCO₃ → Na₂CO₃  + CaCl₂

This reaction redoks mix both kichen salt and ammonia.

2NaCl + CO₃ + NH₃ + H₂O → NaHCO₃ + NH₄Cl (1)

CaCO₃ → CO₂ + CaO (2)

2NH₄Cl + CaO → 2NH₃ + CaCl₃ + H₂O (3)

2NaHCO₃ → Na₂CO₃ + H₂O + CO₂ (4)

Sodium bicarbonate is a rather alkaline amphoteric compound,

HCO_3-+ H₂O → H₂CO₂ + OH^-

The reaction of sodium bicarbonate and acids derivates salt and carbonic acid, which readily decompose into carbon dioxide and water.

NaHCO₃ + HCl → NaCl + H₂CO₃ (1)

H₂CO3₃ → H₂O + CO₂ (2)

Generally, above 60°C temperature, it will gradually break down to sodium soda, water and carbon dioxide. At 200°C most of bicarbonates go though dehydration reactions. The continue of heating temperature will turn sodium to oxide, it may about 1000°C at thermal decomposition.

2NaHCO₃ → Na₂CO₃ + H₂O + CO₂

Bellow is reaction of sodium bicarbonate and vinegar.

NaHCO₃ + CH₃COOH → CH₃COONa + H₂O + CO₂ (gas)

Vinegar is corrosive for many metals such as iron, magnesium, and zinc, the raction form hydrogen gases and acetate salts and also calleda as cetic metals. The acetic metal may be obtained by acetic acid reaction with a suitable base. A famous example of baking soda (Sodium bicarbonate) reaction with vinegar. Almost acetic salts dissolve well in water.

Conclusion

The reaction between baking soda and vinegar will produce acetate salt, water and carbon dioxide gas, it can be utilized in various science projects. One of them is making a simple rocket. Vinegar (Acetic acid) is used as a chemical reagent to produce various chemical compounds. Most of acetic acid is used as material to produce vinyl acetate monomers. In addition acetic acid is also use to product acetic anhydride and esters.