Alcoholysis method of waste recycled plastics

Alcoholysis is the process of alcoholizing some of the polymers and recovering the raw materials using the hydroxyl groups of the alcohols. This method can be used for polyurethane, polyester and other plastics.

Hydrogenated esters: Polyurethanes produce a mixture of amines and glycols after hydrolysis, and they need to be separated before they can be recycled. The alcoholysis process does not require this process and the process is quite simple.

The spent polyhydric ester foam (both soft and hard) can be alcoholized at 185 to 200°C in the presence of ethylene glycol. The alcoholysis process also includes carbonate groups in the polyurethane foam. Ester transfer with glycol solvent. This reaction produces only one product, a polyol mixture. This recovered mixed polyol can be reused without separation. Foams produced using glycol recovered glycols are virtually indistinguishable from those produced using neat glycols. Alcoholysis also applies to the decomposition and recycling of isocyanate foam waste.

Industrially, the alcoholysis process is also very simple. The pre-shredded or ground waste polyurethane foam is sent to a reactor equipped with ethylene glycol and reacted in a nitrogen atmosphere at 185 to 200°C. The rate of waste into the reactor depends on the agitation method, material type, and heat transfer mode. Stir well and mix well so that the foam does not float on the glycol surface. In the alcoholysis recovery of polyurethane foam waste, it is also possible to add organic metal compounds and tertiary amine catalysts.