Synergistic antimicrobial compositions containing an ionene polymer and a salt of dodecylamine and methods of using the same

A method of controlling the growth of at least one microorganism in or on a material or medium susceptible to attack by microorganism comprising the step of adding to the material or medium a composition comprising (a) an ionene polymer and (b) a salt of dodecylamine in a synergistically microbicidally effective combined amount to control the growth of at least one microorganism, wherein the ionene polymer comprises the repeating unit of formula I:

• ##STR5## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are identical or different, and are selected from hydrogen, C.sub.1 -C.sub.20 alkyl optionally substituted with at least one hydroxyl group, or benzyl optionally substituted on the benzene moiety with at least one C.sub.1 -C.sub.20 alkyl group;
• A is a divalent radical selected from C.sub.1 -C.sub.10 alkylene, C.sub.2 -C.sub.10 alkenylene, C.sub.2 -C.sub.10 alkynylene, C.sub.1 -C.sub.10 hydroxyalkylene, symmetric or asymmetric di-C.sub.1 -C.sub.10 -alkylenether, arylene, arylene-C.sub.1 -C.sub.10 -alkylene, or C.sub.1 -C.sub.10 -alkylenearyl-C.sub.1 -C.sub.10 alkylene;
• B is a divalent radical selected from C.sub.1 -C.sub.10 alkylene, C.sub.2 -C.sub.10 alkenylene, C.sub.2 -C.sub.10 alkynylene, C.sub.1 -C.sub.10 hydroxyalkylene, arylene, arylene-C.sub.1 -C.sub.10 -alkylene, or C.sub.1 -C.sub.10 -alkylarylene-C.sub.1 -C.sub.10 -alkylene;
• and
• X.sup.2- is a divalent counter ion, two monovalent counter ions or a fraction of a polyvalent counter ion sufficient to balance the cationic charge in the repeating unit which forms the ionene polymer backbone.

A method for preventing spoilage of a material or medium caused by bacteria or fungi or algae comprising the step of adding to the material or medium a composition comprising (a) an ionene polymer and (b) a salt of dodecylamine in a synergistically microbicidally effective combined amount to prevent spoilage, wherein the ionene polymer comprises the repeating unit of formula I:

• ##STR6## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are identical or different, and are selected from hydrogen, C.sub.1 -C.sub.20 alkyl optionally substituted with at least one hydroxyl group, or benzyl optionally substituted on the benzene moiety with at least one C.sub.1 -C.sub.20 alkyl group;
• A is a divalent radical selected from C.sub.1 -C.sub.10 alkylene, C.sub.2 -C.sub.10 alkenylene, C.sub.2 -C.sub.10 alkynylene, C.sub.1 -C.sub.10 hydroxyalkylene, symmetric or asymmetric di-C.sub.1 -C.sub.10 -alkylenether, arylene, arylene-C.sub.1 -C.sub.10 -alkylene, or C.sub.1 -C.sub.10 -alkylenearyl-C.sub.1 -C.sub.10 -alkylene;
• B is a divalent radical selected from C.sub.1 -C.sub.10 alkylene, C.sub.2 -C.sub.10 alkenylene, C.sub.2 -C.sub.10 alkynylene, C.sub.1 -C.sub.10 hydroxyalkylene, arylene, arylene-C.sub.1 -C.sub.10 -alkylene, or C.sub.1 -C.sub.10 -alkylarylene-C.sub.1 -C.sub.10 -alkylene;
• and
• X.sup.2- is a divalent counter ion, two monovalent counter ions, or a fraction of a polyvalent counter ion sufficient to balance the cationic charge in the repeating unit which forms the ionene polymer backbone.