Polymer synthesis by direct polycondensation, ordered

UEDA OKADA Ordered Polymer Synthesis by Direct Polycondensation 445... 

Our group has initiated a synthesis of ordered polymer from nonsymmetric monomers by direct polycondensation. In the previous papers, we reported a successful synthesis of ordered polyamides (head-to-head or tail-to-tail) from a synunetric monomer and a nonsynunetric monomer, (7,2), and ordered polyamides (head-to-tail) from a synunetric monomer and a nonsynunetric monomer or a pair of two synunetric monomers (3). 

On the basis of the above findings, we initiated the synthesis of ordered (-abedef-) polymer from three nonsymmetric monomers, XabX, YcdY and ZefZ by direct polycondensation. 

Recently, we succeeded on the synthesis of ordered(-abcd-) poly(amide-thioether) by poly(addition-direct condensation) of a pair of two nonsynunetric monomers, 4-(actyloxy)benzoic acid (XabX) and 4-aminobenzenethiol (YcdY), where a polyaddtion was combined with a polycondensation to prepare the ordered polymer (4). Because, the selective amidation of carboxylic acids would be difficult using condensing agents due to the small difference of pKa values between carboxylic acids. An active ester is also useful as a substitute for a carboxylic acid component. 

---