Aliphatic dibasic acid ester plasticizers mainly include esters of adipic acid, azelaic acid, and sebacic acid. They are formed by the direct esterification of these dibasic acids with monohydric alcohols. For example, dioctyl sebacate is synthesized by direct esterification of sebacic acid and 2-ethylhexanol.
Aliphatic dibasic acid ester plasticizers are characterized by excellent low-temperature performance. Adding them to polymer materials can increase the embrittlement temperature of materials or products. It can reach -30~-70℃, and sebacate is the most prominent in the application, especially di(2-ethyl)hexyl sebacate (DOS) is the most widely used. Their disadvantage is poor compatibility, so they are generally used as auxiliary plasticizers.
Sebacic acid, the main raw material for the manufacture of sebacic acid ester, is currently mainly cracked from castor oil and is relatively expensive. Therefore, sebacic acid is synthesized from petrochemical raw materials Diacids are still a problem to be solved in the industrial production of plastic plasticizers. In recent years, some synthetic methods have appeared, one of which is to synthesize sebacic acid by electrolytic coupling using monomethyl adipate as raw material. There are already industrial production abroad.
The cold resistance of azelaic acid ester is also good. However, the source of azelaic acid is relatively difficult and the price is relatively expensive. The cold resistance of adipate is also good, but it is similar to DOA (dioctyl adipate): the molecular weight is small, the volatility is also high, and the use is limited. The cold resistance of straight-chain alcohol esters of adipate is better than DOA , and less volatile.
In recent years, a dodecane dicarboxylate has appeared, which has good cold resistance. The raw material of the cold-resistant plasticizer is dodecanedicarboxylic acid, which is based on butadiene. Prepared by cyclotrimerization, hydrogenation, oxidation.
The esterification of dodecanedicarboxylic acid and alcohol can produce dodecanedicarboxylate.
This kind of plasticizer is a promising cold-resistant plasticizer due to its rich source of raw materials and good low-temperature performance.
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