Isopropyl alcohol
- Propanol -2
- Isopropanol
- I- propanol
- Isopropyl alcohol ( IPA)
- Secondary propyl alcohol
- Sec -propanol
- Persprit
- Petrohol
- Petrosol
- Dimethylcarbinol
- β - hydroxypropan
- Propol
- Alcohol isopropylicus
Colorless liquid with an alcohol odor
Liquid
0.78 g · cm -3
-88 ° C
82 ° C
43 hPa ( 20 ° C)
Completely miscible with water, ethanol, acetone, chloroform, benzene,
1.37927 (20 ° C)
Risk
200 ml · m -3 and 500 mg · m-3
Template: Infobox chemical / molecular formula search available
2-propanol, as well as isopropyl alcohol or isopropyl alcohol ( abbreviated as IPA ), is the simplest non- cyclic secondary alcohol.
Representation and extraction
The industrial production of 2-propanol is carried out by hydration of propene to acidic ion exchange resins as the catalyst:
Alternatively, 2-propanol are obtained by catalytic hydrogenation of acetone:
By reversing the second reaction of acetone is produced on a large scale from isopropanol by oxidative dehydrogenation, ie dehydration with simultaneous oxidation of the resulting hydrogen with oxygen to form water.
Properties
Physical Properties
Isopropanol is a colorless, volatile and flammable liquid having a slightly sweet, pungent smell with a stronger inhalation, - this is characteristic and reminiscent of hospitals and medical clinics, because isopropanol is part of many disinfectants. At -88 ° C, the liquid solidifies to a colorless solid. The boiling point under normal pressure at 82 ° C. Isopropanol is homogeneously miscible with water in all proportions and forms a constant boiling ( azeotropic ) mixture at 80.4 ° C and 12.1 % water content. The compound is formed with a number of other solvent azeotropically boiling mixtures. The azeotropic compositions and boiling points are given in the following table. With methanol, ethanol, 1-propanol, n-butanol, iso- butanol, sec-butanol, cyclohexanol, ethanediol, ethylbenzene, acetone, diethyl ether, 1,4-dioxane, methyl acetate and dimethylformamide no azeotropes are formed.
Thermodynamic properties
The vapor pressure function is given by Antoine corresponding log10 (P) = A- ( B / ( T C )) ( P in bar, T in K) with A = 4.57795, B = 1221.423 and C = -87.474 in temperature range from 359.0 to 508.24 K.
The temperature dependence of the enthalpy of vaporization can be determined according to equation ΔVH0 = A · e ( - αTr ) (1- Tr) β ( ΔVH0 in kJ / mol, Tr = (T / Tc) reduced temperature ) with A = 53.38 kJ / mol, α = -0.708, β = 0.6538 and Tc = 508.3 K describe the temperature range between 298 K and 380 K.
Temperature dependence of the heat of evaporation of 2-propanol
Safety characteristics
2- propanol forms flammable vapor - air mixtures. The compound has a flash point of 12 ° C. The explosion range is from 2 vol % (50 g/m3) as the lower explosive limit ( LEL) and 13.4 % by volume (335 g/m3 ) and upper explosive limit (UEL ). A correlation of the explosion limits of the vapor pressure of function results in a lower explosion point of 10 ° C and an upper explosion point of 39 ° C. The explosion limits are temperature and pressure dependent. Increased temperatures lead to an expansion of the explosion range. A decrease in the pressure leads to a reduction of the explosion range. The lower explosive limit changes up to a pressure of 100 mbar little and increases only at pressures less than 100 mbar. The upper explosive limit reduced analogously with decreasing pressure.
The limiting oxygen concentration at 20 ° C with 8.7 vol% at 100 ° C at 8.1 vol%. The marginal gap width was determined to be 0.99 mm. The result is thus a mapping in the explosion group IIA. The ignition temperature is 425 ° C. The fabric falls within the temperature class T2. The electrical conductivity is relatively low, at 5.8 · 10-6 S · m -1. In aqueous solutions, the flash point varies with <20 ° C to a water content of 80 mol % only slightly.
Flash point function of 2-Propanol/Wasser-Gemischen
Chemical Properties (Security)
2- propanol, as also form other secondary alcohols with oxygen in the air explosive peroxides. For example, a peroxide content of 1% was noted in containers in which isopropanol was kept for ten years; Peroxide concentrations of up to 4.2% have been reported. While distilling off 2-propanol to dryness, it is therefore come to some serious accidents. It is therefore advisable to check isopropanol before distilling to peroxides.
Toxicology
The vapors are anesthetic. The contact causes irritation of eyes and mucous membranes. When dealing for adequate ventilation. In animal studies, no evidence was found to sensitizing or mutagenic properties.
Use
- Solvent for fats, resins, paints, ink
- Extraction and purification of natural products
- Solvent for crystallization and purification of organic substances
- Precipitation of nucleic acids
- Cleaner ( degreaser ) in industrial and domestic
- Solvents and diluents used in cosmetic and pharmaceutical preparations
- Addition to antifreeze in the cooling system or the windshield washer system in cars and trucks
- Part of the door lock and Autoscheibenenteisern
- Part of so-called fuel system cleaners that are added to the fuel of motor vehicles in order to solve residues and water in the system
- Additive in offset presses with alcohol dampening to reduce the surface tension of the fountain solution (so-called " mop water additive")
- Manufacture of disinfectants ( 70% IPA for example, in water has a higher effect than appropriately diluted ethanol)
- Defoaming
- Starting material in the Meerwein - Ponndorf -Verley reduction of aldehydes or ketones
- Production of isopropylamine
- For wet play records: 50 % isopropanol mixed with 50 % distilled water
- To remove grease, lubricants and silicone residues in preparation for painting of vehicles. Mixture is diluted with up to 50 percent water
- For cleaning of optical surfaces ( lenses and eyepieces ), especially in microscopy: 15 % isopropanol with 85 % n -hexane ( recommendation of Carl Zeiss MicroImaging GmbH)
- Cleaning of soldered boards, removal of flux residues (only alcohol- based flux )
- Removal of sweating (after curing under UV light) in the nails
- The alcohol component in cloud chambers
According to EU Directive 98/8/EC of 16 February 1998 biocidal products should be only admitted whose active ingredients in Annex (Annex I, IA and IB) of that Directive have been included ( for the defined product ). In accordance with the transitional arrangements (Article 16, paragraph 1 of Directive 98/8/EC ) the placing of biocidal products where these agents with stitch Date 14 Mai was, however, allowed to continue, not containing the active substances listed in the Annex to Directive 98/8/EC, 2000 already on the market were (also " existing active substances " called ).
, Reported in accordance with EU Regulation 1896/2000 of 7 September 2000 had vendors who request that an "old drug " in Annexes I, IA and IB, the active substance concerned until 28 March 2002 on the notification for the relevant product have. This deadline was extended with EU Regulation 1687/2000 of 25 September 2002 to 31 January 2003. The " notified active substances " were allowed to remain on the market following up to the final decision on inclusion or non-inclusion in Annex I, IA and IB EU Directive 98/8/EC.
The active ingredient propan-2 -ol has been following for product types 1 to 6, added to the list of notified active substances 9 to 12 and 18.
By order of 14 August 2007 for the PT 18 (insecticides ), by decision of 14 October 2008 for product types 3 ( veterinary hygiene ), 5 ( drinking water disinfectant) and 6 ( in-can preservatives ) and by decision of 8 February 2010 for the product groups 9-12 (various preservatives) are decisions that include the active substance propan-2 -ol is not in the appropriate list ( Annex I / IA of Directive 98/8/EC ) for the mentioned product types. The release of biocidal products containing the active ingredient propan-2 -ol, is thus in the EU ( Switzerland has adopted this provision ) is no longer allowed for the corresponding product types. For the product groups 1 ( human hygiene ), 2 ( disinfectant for the private sector ) and 4 ( disinfectant for the food and feed area ) of the decision is pending.