Polypropylene Glycol, Polyglycol P-4000 is a linear polymer produced by controlled, catalysed reaction between propylene oxide and water. The letter P and the number 4000 indicate that the polymer is propylene oxide based and that the approximate average molecular weight is 4000.
PPG P-4000, as this product is also known, is a clear, viscous liquid at room temperature. It has a higher pour point and unlike the lower molecular weight PPGs, is partially soluble in water at 77F (25C). It loses its water solubility at higher temperatures.
Like all polypropylene glycols, Polyglycol P-4000 is soluble in all proportions with any organic solids and liquids, the main exception being long chain aliphatic hydrocarbons. Polyglycol P-4000 possesses excellent lubricity and has a low vapor pressure. Underextreme heating conditions it does not form coke nor does it form a varnish. Decomposition products are low boiling products that are either lost as volatiles or soluble in the polypropylene glycol.
