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Improve Product Water Resistance, Flexibility
Jan 09, 2018

Diethyl phthalate (DEP), also known as diethyl phthalate or ethyl phthalate, is a non-toxic, colorless, transparent, oily liquid that can be used in the plasticization of plastics and fiber resins. Its low temperature Flexibility and durability superior to dimethyl phthalate, often with dimethyl phthalate and used in cellulose acetate, to improve product water resistance, flexibility, light resistance and hardness; for the nitro-fiber Su-, access to high strength, light resistance, odor-free products . DEP can be used as a tackifier for polyvinylacetate emulsions, as a solvent and lubricant in the manufacture of pharmaceuticals, as a perfume fragrance, as a non-toxic adhesive for food packaging films, as a foaming agent for flotation of colored or non-ferrous metal mines , GC stationary liquid, alcohol denaturants, spray insecticides, rocket propellant stabilizers, etc.Although DEP is somewhat limited in its development due to its high volatility, DEP still has a very large market in other fields such as the production of cellulose acetate and butyrate. The usual method for the synthesis of DEP is the use of alkyd direct esterification. At present, the traditional synthesis method commonly used in China is the esterification reaction of phthalic anhydride and anhydrous ethanol under the action of concentrated sulfuric acid. The esterified liquid is neutralized, dehydrated and fractionated to obtain the finished product. Sulfuric acid has the advantages of strong acidity, strong water absorption and low cost. However, it also has oxidative properties and may cause side reactions such as sulfonation, carbonization or polymerization, resulting in poor selectivity and low reaction yield and corrosion of equipment, produce a lot of waste, causing environmental pollution. The solid acid as a catalyst can avoid the disadvantages of the traditional method, has the advantages of high reactivity, fast reaction rate, short reaction time and good selectivity, and the process is relatively simple and is easy to be industrialized. Not only can overcome the disadvantage of sulfuric acid as catalyst corrosion equipment, pollution of the environment, but also the catalyst can be reused, the utilization rate can be improved. Solid acid catalyst mainly includes molecular sieve type, functional polymer type, heteropoly acid type and solid superacid.