Biostatic and biocidal compositions

A process for rendering a substrate biocidal or biostatic, which comprises applying to the substrate a biocidally or biostatically effective amount of a polymer or copolymer having the repeating polymeric unit ##STR9## or the hydrated diol form thereof, the hemiacetal or acetal form thereof from condensation of the diol form with the aldehyde form, the tetrahydropyran or fused tetrahydropyran form thereof from self-condensation of the diol form, the aldol-Michael self-condensation form thereof or mixtures thereof.

A process for rendering a substrate biocidal or biostatic, which comprises polymerizing acrolein alone or with comonomers in the presence of the substrate material to chemically bind to the substrate, or to incorporate within the substrate, a biocidally or biostatically effective amount of an acrolein polymer or copolymer having at least the repeating polymeric unit ##STR10## or the hydrated diol form thereof, the hemiacetal or acetal form thereof from condensation of the diol form with the aldehyde form, the tetrahydropyran or fused tetrahydropyran form thereof from self-condensation of the diol form, the aldol-Michael self-condensation form thereof or mixtures thereof.

A method of inhibiting microbial growth on a substrate comprising:

• applying a biostatic or biocidal agent to the substrate sufficient to inhibit microbial growth in or on the substrate, wherein the biostatic or biocidal agent is a polymer or copolymer having a repeating polymeric unit ##STR11## or the hydrated diol form thereof, the hemiacetal or acetal form thereof from condensation of the diol form with aldehyde form, the tetrahydropyran or fused tetrahydropyran form thereof from self-condensation of the diol form, the aldol-Michael self-condensation form thereof or mixtures thereof.