Description
2-Methyl-2,4-pentanediol (MPD) is a diol organic compound with a chiral carbon atom. It is a colorless liquid at room temperature and can be Diacetone alcohol is hydrogenated. The appearance is colorless liquid with mild sweetness. It is miscible with water, soluble in ethanol, and soluble in most organic solvents.
Uses
2-Methyl-2,4-pentanediol (MPD) is a fine chemical product with a wide range of uses, which can be used in pesticides, biochemical engineering, photosensitive materials, synthetic fragrances and other fields. 2-Methyl-2,4-pentanediol is a highly soluble high-grade organic solvent. It can be used as an additive in the production of metal surface treatment agents for rust and oil removal. It can also be used as a textile auxiliaries, as well as coatings and latex paints. It can also be used in cosmetics, as a pesticide stabilizer, but also as a daily chemical moisturizer, flavor and fragrance raw materials, hydraulic oil, high-temperature lubricating oil, brake oil, dry cleaning agent, printing ink, pigment dispersant, wood preservative etc. As penetrant, emulsifier and antifreeze.
Preparation
Using 2000 L of diacetone alcohol as a raw material to synthesize isohexanediol by hydrogenation reduction, the specific process steps are:Step 1: Start the vacuum pump to vacuum the raw material metering tank. When the vacuum is greater than -0.06Mpa, close the exhaust valve, open the feed valve, mix 2000 L of diacetone alcohol raw material and 200ppm sodium bicarbonate and pump it in Raw material metering tank.Step 2: Open the vacuum valve on the reduction pot and pump the reduction pot to a vacuum of -0.1Mpa, then open the feed valve on the reduction pot, and add 2000 L of diacetone alcohol raw material and 200ppm sodium bicarbonate from the metering tank To the reduction pot, start the mixer to stir at the same time, add 95Kg of Raney nickel catalyst.Step 3: Close the vacuum valve, open the nitrogen inlet valve, and inject nitrogen into the reduction pot. After the pressure in the pot is increased to 0.6Mpa within 3 to 5 minutes, close the hydrogen inlet valve, open the vent valve, and reduce the pressure in the pot. Reduce to normal pressure, repeat the above steps, re-inject nitrogen for replacement, and repeat this five times.Step 4: When the nitrogen replacement in the third step is completed, close the vent valve, open the hydrogen inlet valve, and inject hydrogen into the reduction pot within 10-15 minutes. When the pressure in the pot reaches 0.6Mpa, close the hydrogen inlet valve. Open the vent valve, after the pressure in the pot drops to normal pressure, close the vent valve, repeat the above steps, re-inject hydrogen for replacement, and repeat this five times.Step 5: After the hydrogen replacement, close the vent valve, open the hydrogen gas inlet valve, and inject hydrogen into the reduction pot. Use hydrogen to make the pressure in the pot reach 1.9Mpa within 15 to 30 minutes, then close the hydrogen gas inlet valve and open it. Jacketed steam valve, raise the temperature in the pot to 150°C, and adjust the stirring speed to 310r/min. At this time, open the hydrogen gas inlet valve and control the temperature in the pot at 150°C. On the basis of the stable temperature in the pot, Keep the hydrogen vapor pressure at 1.9Mpa for 4 hours, then close the hydrogen gas inlet valve and accurately record the current pressure in the boiler. After 30 minutes, take a sample for gas chromatographic testing. If the raw material content is less than 1% in the test result, it is qualified. At this time, Close the jacketed steam valve and open the jacketed cooling water to reduce the temperature in the pot to normal temperature. Then, open the vent valve to reduce the pressure in the pot to normal pressure.Step 6: Stop the mixer and let it stand for 50 minutes, close the vent valve, open the nitrogen inlet valve, use nitrogen to increase the pressure in the pot to 0.6Mpa, close the nitrogen valve, open the empty valve, and slowly reduce the pressure in the pot to normal pressure , And then repeat this step 5 times.Step 7: Open the nitrogen valve and the feed valve of the distillation pot at the same time. Use 0.8Mpa nitrogen to send the qualified materials to the filter for filtration. The filtered materials are pumped into the crude isohexanediol storage tank, and then pressed to the distillation Distillation is carried out in the kettle, and the filtered catalyst is recycled; the finished product from the rectification is isohexanediol. After the raw material of 2000 L diacetone alcohol is hydrogenated and reduced to synthesize, 1865Kg of isohexanediol product is obtained with a purity of 99.5%. The mass yield is 99%. After cooling, it is placed in the isohexanediol product storage tank. The remaining by-products are mainly 29kg of 98% acetone, which can be sold as industrial acetone.
Description
Hexylene glycol is a colorless liquid with amild, sweet odor. The odor threshold is 50 ppm. Molecularweight= 1 18.20; Specific gravity (H20:1) = 0.92; Boilingpoint = 197.8℃; FreezingMelting point= - 50℃ (sets toglass); Vapor pressure = 0.05 mmHg at 20℃;Flashpoint = 98.3℃; Autoignition temperature = 260℃; 306℃.Explosive limits: LEL= 1.3%; UEL= 7.4%.. HazardIdentification (basedon NFPA-704 M Rating System):Health 2, Flammability 1, Reactivity 0. Soluble in water.
Chemical Properties
Hexylene Glycol is an oily colorless liquid with a mild sweet odor. It is an oxygenated solvent derived from acetone which has two alcohol functions. It has a low evaporation rate and it is completely miscible with water.
Uses
hexylene glycol could be considered a solubilizer.
Uses
- Hexylene Glycol is used as a reagent in the synthesis of functionalized boronic esters. it is used in laboratory studies as a precipitant and cryoprotectant in protein crystallography.
- Also used in the preparation of vinylboronates.
- It is mainly used as a coupling agent and an additive to hydraulic fluids, inks and cement. Further, it is used as a solvent for cleaning and colorant products.
- It is a potential substitute for glycol ethers.
- It is an effective shrinkage reduction admixture or SRA for concrete and mortar.
- It can also be used as a building block in chemical synthesis.
- Hexylene glycol is a key solvent in many markets such as paints & coatings, metal working fluids, detergency, cosmetics & fragrances, textiles & leather.It is used to control the flow properties of industrial products such as paints, coatings, cleansers, solvents, and hydraulic fluids. It acts as a thickening agent in cosmetic products.
- It is also employed as a blood volume expander.
Uses
Fuel and lubricant additive; solvent in
cosmetics; solvent in petroleum refining; coupling
agent in hydraulic brake fluid and printing
inks; gasoline anti-icer additive
Uses
(^+)-2-Methyl-2,4-pentanediol is used to control the flow properties of industrial products such as paints, coatings, cleansers, solvents, and hydraulic fluids. It acts as a thickening agent in cosmetic products. It serves as a coupling agent and an additive to hydraulic fluids, inks and cement. It is also employed as a blood volume expander. Further, it is used as a solvent for cleaning and colorant products. In addition to this, it is used in laboratory studies as a precipitant and cryoprotectant in protein crystallography.
Production Methods
2-Methyl-2,4-pentanediol is prepared commercially by the
catalytic hydrogenation of diacetone alcohol . It is used
as a chemical intermediate, a selective solvent in petroleum
refining, a component of hydraulic fluids, a solvent for inks,
and as an additive for cement .
Industrial exposure is likely to be from direct contact or
from inhalation, particularly if the material is heated.
Definition
ChEBI: A glycol in which the two hydroxy groups are at positions 2 and 4 of 2-methylpentane (isopentane).
General Description
Oily colorless liquid with a mild sweet odor. Floats and mixes slowly with water.
Air & Water Reactions
Hygroscopic. Water soluble [Hawley]
Reactivity Profile
2-Methyl-2,4-pentanediol is incompatible with the following: Strong oxidizers, strong acids [Note: Hygroscopic (i.e., absorbs moisture from the air).] .
Hazard
Toxic by ingestion and inhalation; irritant to
skin, eyes, and mucous membranes. Combustible.
Health Hazard
Irritation of eyes, nose and throat; headache, dizziness, and nausea.
Chemical Reactivity
Reactivity with Water No reaction; Reactivity with Common Materials: Can catch fire when in contact with porous materials such as wood, asbestos, cloth, soil, or rusty metals; Stability During Transport: Stable at ordinary temperatures, however when heated this material can decompose to nitrogen and ammonia gases. The decomposition is not generally hazardous unless it occurs in confined spaces; Neutralizing Agents for Acids and Caustics: Flush with water and neutralize the resulting solution with calcium hypochlorite; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
Potential Exposure
”Human Data;Primary Irritant. Hexylene glycol is used in metal workingfluids; the formulation of hydraulic brake fluids; in makingprinting inks. It is used as a fuel and lubricant additive; asan emulsifying agent; and as a cement additive.
First aid
If this chemical gets into the eyes, remove anycontact lenses at once and irri gate immediately for at least15 min, occasionally lifting upper and lower lids. Seek med-ical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, includ-ing resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medi-cal attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.
storage
Color Code- Green: General storage may be used.Prior to working with this chemical you should be trainedon its proper handling and storage. Before entering confinedspace where this chemical may be present, check to makesure that an explosive concentration does not exist. Store in tightly closed containlers; in a cool, well-ventilated areaaway from oxidizers (such as perox ides, perchlorates, chlo-rates, permanganates, and nitrates). Where possible, auto-matically pump liquidfrom drums orotherstoragecontainers to process containers.
Shipping
HexyleneglycolisnotcitedinDOT'SPerformance-Oriented Packaging Standards.'
Purification Methods
Dry the diol with Na2SO4, then CaH2 and fractionally distil it under reduced pressure through a packed column, taking precautions to avoid absorption of water. [Beilstein 1 IV 2565.]
Incompatibilities
Incompatible with strong acids, caustics,aliphatic amines, isoc yanates, strong oxidizers. Hygroscopic(i.e., absorbs moisture from the air). .
Toxics Screening Level
The initial threshold screening level (ITSL) for he xylene glycol (2-methyl-2,4-pentanediol) is 1,210 μg/m3 based on a 1-hour averaging time.
