1, different functions

Propylene glycol has incomparable advantages over ethylene glycol in cavitation resistance, toxicity and biodegradability.

2. Different toxicity

Propylene glycol has little toxicity and can be used in combination with glycerol or sorbitol as a wetting agent in cosmetics, toothpaste and soap. Ethylene glycol is toxic to animals, and the lethal dose to humans is about 1.6 g/kg.

3. Different uses

Propylene glycol can be used as raw material of unsaturated polyester resin. It can be used as a wetting agent in cosmetics, toothpaste and soap together with glycerol or sorbitol. It is used as humidity regulator and hair leveler in hair dyes, as well as antifreeze, cellophane, plasticizer and pharmaceutical industry.

Ethylene glycol is soluble in water and acetone, but insoluble in ether. Used as solvent, antifreeze and raw material for synthetic polyester. Polyethylene glycol (PEG) is a polymer of ethylene glycol, a phase transfer catalyst and also used for cell fusion. Its nitrate ester is an explosive.

References:

Baidu encyclopedia-propylene glycol

References:

Baidu encyclopedia-ethylene glycol