Some Properties of Polyvinylformal

Acetic acld is a good solvent for pOlyvinylformal. There wa円a parallel rdation between the soluble property and the acid concentration. Acetic acid did not attack pulyvinyl formal at room temperature，b ut at boiling point some acetal percentage was lowered，and the solution viscosity was dropped. Dilute hydrochloric acid attacked acetal radical but solution viscosity was littlelowered