Green Solvent: Ethyl Lactate

Ethyl lactate has been attracting increasing attention as a green medium in organic synthesis.This solvent has the unique advantages of being non-toxic, low cost, fully biodegradable, high boiling point and good compatibility with water and most organic compounds, making it ideally suited as a green reaction medium.

Ethyl lactate is a clear, colorless liquid produced by the fermentation of carbohydrates similar to sugar. It has special properties such as rum, Fruit and cream aromas. Soluble with most organic solvents, partially hydrolyzed when miscible with water. It is mainly used as a solvent for interbody synthesis of pharmaceutical pesticides, resin, coatings, etc., and also used as flavoring agent for liquor.

Ethyl lactate has many attractive properties that translate into environmental benefits and performance advantages. It is 100% biodegradable and breaks down to carbon dioxide and water. It is easily recyclable and cost effective. It is non-corrosive, non-carcinogenic, non-ozone depleting, and has no oral or inhalation toxicity issues. It does not contain environmentally harmful ingredients or global warming compounds. It is considered a very low-volatility volatile organic compound because it evaporates slowly.

As a solvent for formulated products such as coatings, ethyl lactate has high solvency capacity, high boiling point, low vapor pressure and low surface tension, and improves the performance of various resins, polymers and dyes. Good wettability for various pigments and good permeability in natural materials are other performance characteristics.

Its high solubility makes it an ideal solubility booster in high solids coatings; provides solubility, pigment wetting and formulation stability in dispersed pigments and concentrated inks; and is used for resin solubility, surface wetting and evaporation rate control in phenolic, polyvinyl phenol, diazo and nitrocellulose resins.

When formulating coatings for polystyrene surfaces, its ability to etch certain types of plastic substrates improves adhesion. For wood, polystyrene and metal coatings, it improves penetration, adhesion, pigment wetting and provides resin solubility; in leather and wood coatings, it has low surface tension and chemical affinity for natural materials, contributing to good penetration.

 

The application of ethyl lactate goes beyond its use in coatings. It has proven to be a very effective paint stripper and graffiti remover. Because it replaces long-accepted solvents such as NMP, toluene, acetone and xylene as the standard, ethyl lactate helps make the workplace safer. It does not require extensive venting or concern about EPA requirements. The combination of low VOC and non-carcinogenic materials means there are no exposure limits.

In pre-production surface treatment, ethyl lactate is an excellent cleaning agent without the hazards and concerns of conventional products. As a wiping solvent, for example, it is particularly suitable for metal surface preparation operations on large objects such as aircraft fuselages or wings. For pre-bonding and pre-coat cleaning of metal surfaces, it can be used directly or mixed with other solvents. It is effective in removing grease, oil, adhesives and solid fuels. Evaporation is particularly suitable for this type of application as it is slow enough to completely penetrate contaminants without adversely affecting the overall operation.