Fractal polymers and graft copolymers formed from same

A star copolymer comprising:

• a) a porous, three-dimensional, branched fractal polymer core comprising:
• i.) one to four aromatic nuclei of the formula:
• --(A.sub.1).sub.a --R.sub.1 --(B.sub.1).sub.b --
• ii.) a branched polymeric moiety bonded to and projecting away from said nuclei having branching recurring monomeric units of the formula:
• --(B.sub.2).sub.c --R.sub.2 --(A.sub.2).sub.d --
• which branching recurring monomeric units may be optionally linked by
• iii.) linear aromatic polymer segments comprised of one or more recurring extension monomeric units of the formula:
• --B.sub.3 --R.sub.3 --A.sub.3 --
• in a ratio of between about 0.25 to about 1 moles branching recurring units to between about 0 to 1 mole extension monomeric units, said aromatic polymer segments, a portion of said branching moieties, or a combination thereof having one or more terminating groups of the formula selected from the group consisting of (B.sub.2).sub.c --R.sub.2 --(Z.sub.1).sub.d, --(A.sub.2).sub.d --R.sub.2 --(Z.sub.2).sub.c, --B.sub.3 --R.sub.3 --Z.sub.1, --A.sub.3 R.sub.3 --Z.sub.2, and combinations thereof;
• and
• b.) an average of nine or less graft linear polymeric moieties selected from the group consisting of linear polyamide and linear polyester, which may be the same or different, covalently bonded to the exterior of said core by way of divalent exterior linking moieties of the formula:
• --Z.sub.1 --
• when c is greater than d, and of the formula:
• --Z.sub.2 --
• when d is greater than c, wherein:
• --Z-- is selected from the group consisting of --C(O)OH, --N.dbd.C.dbd.O, and --C(O)Cl and is the residue formed by reaction of an exterior --Z.sub.1 group of said core and a --Z.sub.2 group substituted to a linear polymer precursor of said linear polymeric moieties;
• --Z.sub.2 -- is selected from the group consisting of --NH.sub.2 and --OH and is the residue formed by reaction of an exterior --Z.sub.2 group of said core and a --Z.sub.1 moiety substituted to a linear polymer precursor of said linear or substantially linear polymeric moieties;
• a and b are different and are integers equal to 0, or equal to or greater than 3, with the proviso that a or b is 0;
• R.sub.1 is a polyvalent aromatic group selected from the group consisting of phenyl, biphenyl, and naphthyl, or is an aromatic moiety comprising two or more aromatic groups linked together by a linking moiety selected from the group consisting of ester, urethane and amide linkage;
• R.sub.2 and R.sub.3 are the same or different at each occurrence and are a polyvalent aromatic group selected from the group consisting of phenyl, naphthyl, and biphenyl;
• --Z.sub.2 is the same or different at each occurrence and is a nucleophilic group which is capable of reaction with a --Z.sub.1 group to form a covalent bond or a derivative thereof;
• --Z.sub.1 is the same or different at each occurrence and is electrophilic group which is capable of reaction with --Z.sub.2 group to form a covalent bond or a derivative thereof;
• A.sub.1, A.sub.2 and A.sub.3 are the same or different at each occurrence the residue of a nucleophilic group formed by a reaction between a nucleophilic group Z.sub.2 and an electrophilic group Z.sub.1 ;
• B.sub.1, B.sub.2 and B.sub.3 are the same or different at each occurrence and is the residue of an electrophilic group formed by reaction between a nucleophilic group --Z.sub.2 and an electrophilic group --Z.sub.1 ;
• and
• c and d are different and are integers equal to or greater than 1, with the proviso that the sum of c and d is equal to or greater than 3, and with the further proviso that when a is equal to 0 then d is greater than c and that when b is equal to 0 then c is greater than d.