Dialkyl Succinates and Adipates as Alternative Plasticizers-Even More Efficient Synthesis

Area of Science:

• Green Chemistry
• Organic Synthesis
• Materials Science

Background:

• Phthalate plasticizers face strict regulations, driving demand for safer alternatives.
• Dialkyl succinates and adipates are emerging as viable non-phthalate plasticizer options.

Purpose of the Study:

• To develop an efficient and sustainable synthetic method for dialkyl succinates and adipates.
• To utilize ionic liquids as recyclable catalysts and solvents for esterification.

Main Methods:

• Esterification of succinic and adipic acids with butan-1-ol and 2-ethylhexan-1-ol.
• Synthesis of acidic ionic liquids from triethylamine and sulfuric acid.
• Utilizing a two-phase liquid-liquid system to drive the reaction equilibrium.

Main Results:

• High yields (99%) and selectivities (>99%) for dialkyl succinates and adipates were achieved.
• Mild reaction conditions (70-80 °C) and efficient catalyst recycling (10 times) were demonstrated.
• A simple product isolation procedure and high ester purity were obtained.

Conclusions:

• The developed method is highly efficient, sustainable, and promising for industrial production of non-phthalate plasticizers.
• The use of recyclable ionic liquid catalysts offers significant environmental and economic benefits.
• This approach provides a competitive alternative to traditional plasticizer synthesis.