starch
It comes from plants such as rice, wheat, millet, sweet potato and water chestnut. White, slightly shiny, tasteless, containing some water. When heated to 100℃, water will escape, but if it is still exposed to the air, it can gradually absorb the water in the air for a long time and return to its original state. It is insoluble in water, alcohol and ether, but if heated to about 50 degrees with water, its cell membrane will rupture and expand into a transparent paste. If heated to above 160 degrees, it will become dextrin. Wheat starch and rice starch are the best starches for paste making, because their adhesion is stronger than other starches.
Liquid carbolic acid
That is, 9 parts of solid carbolic acid is heated in a water bath to melt it completely, and then 1 part of distilled water is added and mixed with it until it is completely uniform. Carbonic acid is a colorless slender needle-like crystal with a special smell. If exposed to the air, it will absorb water for a long time, and Beijing opera will turn rosy, which is extremely corrosive and will turn white when exposed to skin. Put four parts of water into the container, and then slowly drop one part of concentrated sulfuric acid. When preparing dilute sulfuric acid or using sulfuric acid, we must pay strict attention to it, and we must slowly inject sulfuric acid into water, otherwise, if water is injected into sulfuric acid, it will produce huge heat energy, which will produce an explosion sound, which will often splash on the skin, and sometimes even cause an explosion because the container cannot be heated. Pure sulfuric acid is a colorless oily liquid, which is distilled from green alum, so it is called alum oil. Completely anhydrous sulfuric acid is impure after cooling. Generally, it contains 5-7% moisture and various impurities, such as hydroxide, arsenic and lead, so it is dark brown, not colorless. Sulfuric acid has strong water absorption capacity, and when it is mixed with water, it will generate huge heat, so it must not be dropped into concentrated sulfuric acid to cause bursting. Sulfuric acid is widely used, ranking first among all acids. It is not only an important reagent in the laboratory, but also a raw material for chemical industry, such as manufacturing nitric acid, hydrochloric acid, explosives and pigments, and refining petroleum.
Glycerol is a trivalent essence.
Often mixed with difficult fatty acids, it exists in the animal kingdom. Glycerol is a by-product of making soap. After extracting this by-product, it was distilled to thicken it, and then bone charcoal was added to decolorize it, thus obtaining glycerol on the market. Pure glycerol is a colorless, clear and viscous liquid, odorless and sweet. It can be mixed with water and essence at will, but insoluble in ether, chloroform and carbon dioxide. It can absorb moisture in the air without any chemical change or evaporation. If heated, it will fly away in the form of yellow-brown smoke, leaving no solid matter behind. Glycerol can dissolve skin color, so it is used to make cosmetics to protect skin, and it is used to make preservatives, medicines, inks and explosives in industry.
dextrin
It is the decomposition product of starch, which can be obtained by heating starch to above 160℃, but it has always been prepared by the thermal method of adding acid to starch in industry. The method is to take 10 portion of starch, add 1 portion 10% dilute nitric acid, mix well, dry in the sun, and then heat to 140℃ in oil bath. The white dextrin made at this temperature is white. If heating is continued or the time is prolonged or the temperature is raised, it will turn yellow and become yellow dextrin. Dextrin is a white or yellow amorphous dry powder, which can be dissolved in the same amount of water and has strong adhesion.
Chemical slurry manufacturing formula:
Flour 100, clear water 100, concentrated sulfuric acid 2, glycerol 1-5, salicylic acid 3, and a little alcohol. First, pay concentrated sulfuric acid and slowly inject water into it to turn it into dilute sulfuric acid, then slowly add flour, stir with a bamboo stick until it is dissolved evenly, if there are small pieces, knead them into a thin paste with your fingers, then slowly heat them on fire, and when they are continuously stirred to a transparent liquid, add glycerol and salicylic acid dissolved in wine, cool them and bottle them.
20 parts of white dextrin, 30 parts of alum, 30 parts of water, 2 parts of glycerol and liquid carbolic acid 1 part.
Starch 1, water 7, alum 0.3, a little antiseptic (such as carbolic acid) and perfume. All the above methods are made by thermal method, and about 30 boxes of 160 g paste can be made per kilogram of starch, which has remarkable economic benefits.