Time for our next experiment, and this is a fun one.
>Nitrocellulose, or NC
Nitrocellulose is a very simple explosive that is actually pretty unfriendly to make. The process isn't hard, but getting the material pure enough and neutralized enough to keep it from spontaneously exploding makes it one of the hardest explosives to make. Easy to do, but a bitch to do right. NC is a very old explosive, and the main ingredient in several very useful explosive compositions, including one that is a neat piece of history.
>Nitrocellulose (also: cellulose nitrate, flash paper, flash cotton, flash string) is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it was originally known as guncotton. Nitrocellulose plasticized by camphor was used by Kodak, and other suppliers, from the late 1880s as a film base in photograph, X-ray films and motion picture films; and was known as nitrate film. After numerous fires caused by unstable nitrate films, safety film started to be used from the 1930s in the case of X-ray stock and from 1948 for motion picture film.
>Henri Braconnot discovered in 1832 that nitric acid, when combined with starch or wood fibers, would produce a lightweight combustible explosive material, which he named xyloïdine. A few years later in 1838 another French chemist Théophile-Jules Pelouze (teacher of Ascanio Sobrero and Alfred Nobel) treated paper and cardboard in the same way. He obtained a similar material he called nitramidine. Both of these substances were highly unstable, and were not practical explosives. However, around 1846 Christian Friedrich Schönbein, a German-Swiss chemist, discovered a more practical solution. As he was working in the kitchen of his home in Basel, he spilled a bottle of concentrated nitric acid on the kitchen table. He reached for the nearest cloth, a cotton apron, and wiped it up. He hung the apron on the stove door to dry, and, as soon as it was dry, there was a flash as the apron exploded. His preparation method was the first to be widely imitated—one part of fine cotton wool to be immersed in fifteen parts of an equal blend of sulfuric and nitric acids. After two minutes, the cotton was removed and washed in cold water to set the esterification level and remove all acid residue. It was then slowly dried at a temperature below 100 °F (about 38 °C). Schönbein collaborated with the Frankfurt professor Rudolf Christian Böttger, who had discovered the process independently in the same year. By coincidence, a third chemist, the Brunswick professor F. J. Otto had also produced guncotton in 1846 and was the first to publish the process, much to the disappointment of Schönbein and Böttger.
This preparation is sourced from "The Chemistry of Powder and Explosives", which you can find in the thread in /z/ with some modifications made by me.
>Detonation velocity: ~7300m/s
>Sensitivity: Mild to shock and vibration. Severe to flame, spark, and heat.
>Volatility: Low, stores easily for long periods if pure.
>Brisance: Low to moderate.
>VERY spark and flame sensitive. The slightest zap will send it up in a roaring whoosh of flame. Explodes with modest power when confined.
>Concentrated nitric acid
>Concentrated sulfuric acid
>Pure white cotton balls, free of perfumes, dies, and chemicals
>Four medium to large beakers
>Lots of distilled water
>An ordinary oven
First start by cleaning and drying the cotton.
>Boil a few cotton balls in a beaker of distilled water for ten minutes, stirring gently, let the mixture cool and carefully remove the cotton balls to a clean ceramic plate. Let them air dry in a clean spot for a day or until totally dry, and then place the plate of cotton in the oven at 100 degrees and dry them for 2 hours. DO NOT SKIP THIS STEP! Impurities in the cotton are the most frequent cause of failed synths and accidents when making NC, and the cotton must be absolutely dry.
>In another beaker, pour 75ml of sulfuric acid. Then, VERY CAREFULLY, add an equal volume (75ml) of nitric acid to it and stir them together well with a glass stirring rod. What you are making is a VERY powerful, concentrated nitrating solution commonly called "mixed acid."
>Measure out five grams of the clean, dry cotton and drop it into the beaker of mixed acid, and immediately stir it into the acid with a glass stirring rod. BEWARE OF TOXIC FUMES! Use good ventilation!
>Allow the cotton to sit in the acid for 30 minutes, stirring it every 3 to 5 minutes for 30 seconds at a time. Temperature control is less critical in this reaction than some others. During breaks in the stirring, prepare a 500ml beaker of cold distilled water, and bring another 500ml beaker of distilled water to a boil and set them nearby.
>After 30 minutes, the cotton ball should be removed from the beaker. As you take it out, press it up against the side of the beaker with your stirring rod and squeeze as much acid as possible out of it. IMMEDIATELY DROP IT INTO THE BEAKER OF COLD WATER.
>Stir the cotton ball in the water vigorously, to try and get as much acid as possible out of it. After a minute or two of stirring, transfer the cotton to a funnel lined with filter paper, and wash it under cold running (distilled) water, prodding at it gently with a glass stirring rod, to remove more acid.
>After washing it this way, place it in a large beaker of gently boiling distilled water and boil the cotton for one hour. Then transfer the cotton to a new, clean beaker of distilled water and boil it again for a half hour. THEN remove it, place it in ANOTHER clean beaker, and boil for a half hour more! DO NOT SKIP THESE STEPS IF YOU LIKE YOUR HANDS AND FACE. You cannot neutralize NC, because the baking soda will form an impurity that can cause detonation. The only way to de-acidify the stuff is by washing the shit out of it - boiling it, in clean water several times.
>After the third boiling, test some of the residue water with litmus paper. ANY TRACE OF ACIDITY MEANS YOU MUST BOIL IT AGAIN.
Once the boilings leave the NC with a completely neutral ph, all that is left is to dry it. Place the cotton balls on a clean plate held at an angle and press out as much water as you can without pressing too hard. Set the plate in a warm, dry spot away from any source of spark or flame and let it air dry for a day. The result is pure nitrocellulose.
Pic related - the exact same process, but done on a haybale-scale!