Formula: Mixture of compounds.
Description: Colophonium is an alcohol soluble resin which is sometimes used as a binder. It is not used very often since it is expensive and doesn't have much adhesion capacity.
Hazards: Colophonium is not particularly toxic or dangerous.
Sources: Artist paint stores often sell colophonium. It is also used by violin players and in the paper industry.
Copper acetoarsenite, Paris green
Formula: Cu3As2O3Cu(C2H3O2) 2
Description: Copper acetoarsenite is a green powder which is used in blue color compositions. It can produce great blues but it is also very poisonous and is used less and less for that reason. Today alternatives are available that will produce deep blues with less poisonous and cheaper compounds.
Hazards: Copper acetoarsenite is very poisonous and should only be handled wearing a dust mask. Smoke from compositions containing this compound should not be inhaled. It is best to avoid the use of this compound altogether as several safer alternatives have become available in the past decades.
Sources: Copper acetoarsenite was used in the past as a pigment known as emerald green, kings green or vienna green. Nowadays it is no longer used and it is very hard to find a paint supplier that still has it. It can be prepared at home but extreme caution must be excercised since arsenic compounds are very poisonous. The following preparation originates from Shimizu: "300 g of copper sulphate is dissolved in 1000 ml water, to which 250 g of glacial acetic acid is added; This solution is named 'A'. Then 200 g of sodium carbonate and 200 g of ersenious acid are added to 1000 ml water and boiled to form a solution, this is named 'B'. B is added little by little to A with constant stirring. Carbon dioxide gas is generated with active bubbling. When all the solution B has been added, it is boiled for about 30 minutes, when copper acetoarsenite appears gradually as green particles in the solution. The mother liquor is removed by vacuum filtration, and then green substance, copper acetoarsenite, is washed with water untill the sulphate ion dissapears; it is then dried. The yield is about 180 g."
Copper benzoate
Formula: Cu(C6H5COO)2
Description: Copper benzoate is a fuel which is used in some blue color compositions. It is not used very often as it is more expensive than most alternatives.
Hazards: Copper benzoate is poisonous and should be handled wearing a dust mask
Sources: Copper benzoate is easily prepared at home from a solution of sodium or potassium benzoate and a soluble copper salt. When these solutions are added together a green precipitate of copper benzoate forms. This is filtered, thoroughly rinsed with hot water and left to dry.
Copper chromite
Formula: ?
Description: Copper chromite is employed as a catalyst is certain rocket propellants. It is typically added in 1 to 5% quantities to whistle or composite rocket fuels which increases the burn rate. A range of other catalysts exist which can often be substituted for copper chromite. Examples are Fe2O3 and MnO2
Hazards: Copper chromite is poisonous and should be handled wearing a dust mask.
Sources: Copper chromite is very hard to make or obtain other than from dedicated pyro chemicals suppliers.
Copper(II)oxide
Formula: CuO
Description: Copper oxide is a black powder employed in blue color compositions in combination with chlorine donors.
Hazards: Copper(II)oxide is poisonous and should be handled wearing a dust mask.
Sources: Copper(II)oxide is usually available from ceramic suppy stores. It is also easily prepared at home as follows: Add a solution of sodium or potassium hydroxide to a solution of a soluble copper(II) compound (copper sulfate for example). This will yield a blue gel-like precipitate of copper(II)hydroxide. Then bring to solution to a boil. The precipitate will turn black and powdery. Boil for a minute or two to complete the reaction and allow the black copper(II)oxide precipitate to settle. Then decant the liquid. Add some boiling hot water to the precipite, stir and allow to settle again. Then decant and repeat 5 more times. This will remove all soluble impurities from the copper(II)oxide. Then the precipitate is filtered and allowed to dry.
Dextrine
Formula: mixture of polysacharides
Description: Dextrine is one of the most commonly used binders in pyrotechincs as it is very cheap and readily available. It is water soluble and can produce rock hard stars.
Hazards: Colophonium is not particularly toxic or dangerous.
Sources: Dextrine is easily prepared from starch. Potatoe and corn starch will both work fine. The starch is spread out on a sheet in a layer about 1 cm thick and placed in the oven. The oven is then heated to 220�C for several hours. The dextrine will turn slightly yellowish brown. One way to check if all the starch has been converted is to dissolve a small sample in boiling hot water and add a drop of KI3 solution. A blue color indicates presence of starch, which means the conversion hasn't completed yet. KI3 solution is conveniently prepared by dissolving a crystal of elemental iodine in a potassium iodide solution.