The copolymerizable ethylenically unsaturated monomers substantially free of alkoxyacrylamide functionality used in the polymerizable composition include vinyl aromatic monomers such as styrene, alpha-methyl styrene, and tertiary butyl styrene; (meth)acrylamidobutyraldehyde dialkyl acetal monomers such as acrylamidobutyraldehyde diethyl acetal (ABDA), methacrylamidobutyraldehyde diethyl acetal (MA