Наш форум практически полностью посвящён ракетам на твёрдом топливе, поэтому тем для жидкостных ракет не хватает.
Не нашёл куда вот это поместить
- а информация может быть полезной. Так что начну тему...
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Dear Mr. V....
Thank you for contacting the Canadian Centre for Occupational Health and Safety with your recent inquiry. Isopropyl alcohol does form peroxides on standing. It can form peroxides when the anhydrous (no water) material is stored for long periods in contact with air and light. The peroxides are not hazardous unless concentrated by distillation. A number of explosions have been reported, which occurred during distillation of isopropyl alcohol following prolonged storage (4 years and longer). The explosions were caused by the presence of peroxides which had become concentrated in the distillation residue. Storage of the alcohol for over-long periods, often under poor conditions, is a common feature of the incidents. Also, the presence of 0.36M peroxide has been reported in a 99.5% pure sample of isopropyl alcohol stored for several months in a partially full clear glass bottle in strong daylight. The reformation of peroxides in de-peroxided isopropyl alcohol within a few days was reported.
The question is where was the bottle stored? Was it stored in the dark and how much air was in the bottle? What type of cap was on the bottle? Screw caps can cause a problem if some of the alcohol with peroxide collected on the cap. If the peroxide was dry, the opening of the screw cap can cause some friction and the peroxide can explode. It will probably be fine to open it bearing in mind what I just wrote, and dilute with water. It is also advisable to open the bottle in a fume hood, preferably behind a glass screen.
However, for safety reasons, if the bottle is 3-4 years old, with unknown amounts of peroxide present, it would be prudent not to use it, but to dispose of it unopened as hazardous waste. The rule is not to open and use bottles containing unknown amounts of peroxides that that have been standing around for more than 1 year. I don’t know what the regulations are in your country concerning disposal of hazardous waste. Certainly not to pour down the drain. If isopropyl alcohol is needed for an experiment, it is better to acquire a fresh bottle of the alcohol and store it in the dark.
If the bottle of isopropyl alcohol has been stored in the dark for the long period in the absence of air then it should be safe to open it. However, the bottle had been opened once and so there was air in the bottle. Under no circumstances should the alcohol be heated or distilled.
The alcohol can be tested for peroxides. Also there are procedures to remove the peroxides. The alcohol can be purified by passage through alumina. When peroxides are removed from solvents by chromatographic adsorption on alumina columns, the concentrated band of strongly adsorbed peroxides at the top of the column may become hazardous if the solvent evaporates. Alternative methods of removing peroxides are to use acidified aqueous ferrous sulfate or aqueous potassium iodide.
I trust you will find this information helpful. If you have additional questions after you read this material or if you require more information, please don’t hesitate to contact the Inquiries Service at 1-800-668-4284.
Occupational Health and Safety Specialist | Spécialiste de santé et sécurité au travail
Inquiries and Client Services | Demandes de renseignements et services à la clientèle
Canadian Centre for Occupational Health and Safety | Centre canadien d'hygiène et de sécurité au travail
135 Hunter St E | 135 rue Hunter est
Hamilton, ON Canada L8N 1M5
Telephone |Téléphone 905-572-2981 x4487 Facsimile |Télécopieur 905-572-4500 Canadian Centre for Occupational Health and Safety
| Centre canadien d'hygiène et de sécurité au travail
Government of Canada | Gouvernement du Canada