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)y (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 monomers other than the acetal-containing or aldehyde-containing monomer; x is at least 2 and y and z are at least 1; 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
-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 monomers.
多糖接枝聚合物由接枝到
多糖基上的含
缩醛或含醛均聚物或共聚物组成,已制备出 Sacch-g-(M')x 或 Sacch-g-(M)y (M')z 和 Sacch-g-(M")x 或 Sacch-g-(M)y-(M")z。M' 和 M "分别代表由一种或多种含
缩醛基团或醛基团的
乙烯基或烯丙基不饱和单体衍生的重复单元;M 代表由一种或多种含
缩醛基团或醛基团单体以外的
乙烯基或烯丙基不饱和单体衍生的重复单元;x 至少为 2,y 和 z 至少为 1; A 和 A'独立地为低级烷基,或 A 和 A'共同形成至少 5 元环状
缩醛;但接枝聚合物在含醛单体时不含有-基团。
当存在醛基时,接枝聚合物不包含-基团。含醛接枝聚合物可用于提高纸张的湿强度。此外,还制备出了各种新型的含
缩醛和醛单体,它们可以接枝聚合到
多糖基材上,或通过传统的乳液聚合技术与
乙烯基可聚合单体聚合。