How to make diethyl phthalate?
1.Diethyl phthalate is industrially produced by the reaction of phthalic anhydride with ethanol in the presence of a concentrated sulfuric acid catalyst. O-phthalic anhydride is formed by an oxidation reaction or an oxidation reaction in the oxidation reaction of ethanol with naphthalene or o-xylene.
2. The phthalic anhydride and anhydrous ethanol are subjected to esterification reaction under the action of concentrated sulfuric acid, and the esterified solution is neutralized, dehydrated and fractionated to obtain a finished product. Traditional industrial production methods.
3. p-toluenesulfonic acid as a catalyst, cyclohexane as a water-carrying agent, phthalic anhydride and anhydrous ethanol as raw materials, esterification reaction to synthesize DEP, the yield was 49.5%. Laboratory production methods.
4. Phthalic anhydride and anhydrous ethanol are ethyl acetate, extracted with diethyl ether, washed with ammonium chloride, water, sodium hydrogencarbonate and water, dried over anhydrous sodium sulfate, and evaporated with diethyl ether. Hydrolysis of % NaOH, and then acid adjustment can obtain cinnamic acid. When the post-treatment is carried out according to this method, the layering is not clear when extracted with diethyl ether, the extraction effect is not good, the yield is not high, and the operation of the method is cumbersome.
5. The ratio of monoethyl malonate potassium salt to benzaldehyde is 1.5:1. The combination of DMAP and diethylamine is used to synthesize cinnamic acid from anhydrous ethanol, which can obtain better products and yield. The method has the advantages of low raw material price, low toxicity, convenient operation and the like, and is advantageous for industrialization.
How to use alpha arbutin powder?
Use a small bag at a time, mix it with a mask powder with about 50 ml of water and apply it to the paste. Spread evenly on the face, avoiding the eye and lip position. After about 15 minutes, peel off from the face from top to bottom and wash with water.
Method of operation
Stir with a small spoon, then apply it to the face like a smear of lime. To form a certain thickness, if it is too thin, the skin will feel tight and uncomfortable when dry. If the thickness is right, it will form a soft film after drying. It can be peeled off after 15 minutes, but it is usually not cleaned by pure rubbing. It should be cleaned with water. Naturally, when you finish the mask, your face is Fresh and moist.
Pay attention to the following when preparing skin care products:
Recommended usage: 0.2%-5%
Arbutin is easy to decompose in acidic environment, pay attention to the pH of the system such as cream emulsion is controlled at 5-7;
The arbutin is dissolved in a small amount of water at 50 ° C, and is added at 50 ° C after the emulsification of the cream is completed;
Adding an appropriate amount of antioxidants to the cosmetic system to prevent discoloration;
After the emulsification of the cream is completed, NaHSO3 and Na2SO3 which have been dissolved with a small amount of water are added at 50 ° C (the recommended addition amount is 0.3-0.4%);
Adding vegetable oil containing oleic acid and linoleic acid can promote the synergistic effect of arbutin;
Adding 0.8 -1.0% azone to the cosmetic system can promote the absorption of arbutin and prevent the precipitation of arbutin on the skin.
Where can i buy edta?
1. If you buy a lot of edta
2. If you buy a small amount of edta
Our website: http://cosmeticchem.com
Where to buy alpha arbutin?
Alpha arbutin inhibits the production and deposition of melanin, removes spots and freckles, and has a whitening effect.
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