Polycationic block copolymer

Claim 1

Block copolymer of the formula: [Q.sub.w L(AL).sub.x (BL).sub.y Q.sub.w ].sup.2(x+y)+ 2(x+y)D.sup.- wherein A is ##STR14## and B is ##STR15## wherein: R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are the same or different and are selected from the group consisting of C 1 -C 3 alkyl, C 1 -C 3 hydroxyalkyl, or hydroxy polyoxyalkylene; D is a halide ion; L is a linkage derived from a dihalide after removal of the halogen atoms, x and y are integers ranging from 1-100 and Q is (BL) y where the bonds between L and A or B are carbon-nitrogen bonds formed by quaternization of the tertiary amine functions of A or B by the organic dihalides from which L is derived and W is 0 or 1 which are obtained by first forming a block of units by reacting a monomer of the formula II ##STR16## wherein each of R 5 , R 6 , R 7 and R 8 are the same or different and is selected from the group consisting of C 1-3 alkyl, C 1-3 hydroxy alkyl hydroxy polyoxyalkylene, m is an integer from 0 to 34 and r and s are the same or different and are integers from 1 to 6, with a molar excess of a dihalide of the formula Hal--L--Hal wherein Hal represents a halogen atom and L is selected from --CH 2 CH 2 --O--CH 2 CH 2 --, --CH 2 CH 2 --O--CH 2 CH 2 --O--CH 2 CH 2 --, --(CH 2 ) t -- or --CH 2 CHOHCH 2 -- where t is an integer from 2 to 6 and thereafter reacting the product so formed with a compound of the formula III ##STR17## wherein R 1 , R 2 , R 3 and R 4 are each individually selected from the group consisting of C 1-3 alkyl, C 1-3 hydroxyalkyl and polyoxyalkylene and p, and q are each individually integers of from 1 to 6 and, if the amount of compound of the formula Hal--L--Hal used in the first reaction was not sufficient to ensure a total molar ratio of compounds of Formulae II and III to those of the formula Hal--L--Hal of 1:1, reacting the product with further compound of the formula Hal--L--Hal.