POLYSACCHARIDE GRAFT POLYMERS CONTAINING ACETAL GROUPS AND THEIR CONVERSION TO ALDEHYDE GROUPS

Polysaccharide graft polymers which comprise an acetal-containing or aldehyde-containing homopolymer or copolymer grafted to a polysaccharide base, represented as Sacch-g-(M')x or Sacch-g-(M')z and Sacch-g-(M")x or Sacch-g-(M)y-(M")z' have been prepared. M' and M" respectively represent repeating units derived from one or more ethylenically or allylically unsaturated monomers containing an acetal group or aldehyde group; M represents a repeating unit derived from one or more ethylenically or allylically unsaturated monamers other than the acetal-containing or aldehyde-containing monomer; x is at least 2 and y and z are at least l; A and A' are independently a lower alkyl or A and A' together form at least a 5-membered cyclic acetal; with the proviso that the graft polymer contain no -?-NH-?- groups when the aldehyde groups are present. The aldehyde-containing graft polymers are useful for imparting wet strength to paper. Various novel acetal- and aldehyde-containing monomers have also been prepared; they can be graft polymerized to polysaccharide substrates or polymerized by conventional emulsion polymerization techniques with vinyl polymerizable monamers.