×

Polyarylates containing derivatives of the natural amino acid l-tyrosine

  • US 5,317,077 A
  • Filed: 03/29/1993
  • Issued: 05/31/1994
  • Est. Priority Date: 06/12/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for the polymerization of polyarylates comprising:

  • mixing equimolar quantities of;

    (a) a diphenol having a structure represented by the formula;

    ##STR12## wherein X is selected from the group consisting of --H, --NHL1, --NL1 L2,;

    ##STR13## Y is selected from the group consisting of hydrogen and ester groups having the structure;

    ##STR14## wherein L1, L2 and L3 are independently selected from the group consisting of straight or branched alkyl and alkylaryl groups containing up to 18 carbon atoms; and

    (b) a dicarboxylic acid having a structure represented by the formula;

    ##STR15## wherein R is selected from the group consisting of saturated and unsaturated, substituted and unsubstituted alkyl, aryl and alkylaryl groups containing up to 18 carbon atoms;

    together with a catalytic amount of 4-(dimethylamino)pyridinium-p-toluene sulfonate (DPTS) in a solvent for said polyarylate; and

    adding at least one molar equivalent per mole of carboxylic acid groups present of a carbodiimide, so that a polyarylate is formed comprised of recurring structural units represented by the formula;

    ##STR16## .

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×