Patent ID: 6156344
Filing Date: 2000-12-05
Classification: A61L,C08G,C08L

Abstract:
A method for improving blood compatibility of an interpenetrating polymer network (IPN) comprising a first macromolecule and a second macromolecule physically interwound together, the method comprising controlling domain size and inhibiting phase separation of a macromolecular mixture while synthesizing an IPN, wherein the first macromolecule is formed by polymerizing and cross-linking a hydrophilic urethane resin represented as the following formula (I) and the second macromolecule is formed by polymerizing and cross-linking a hydrophobic styrene derivative represented as the following formula (II) wherein at least some of the polymerization of one of the macromolecules occurs in the presence of the other macromolecule: ##STR2## wherein R.sub.1 is --[--CHR.sub.3 --CH.sub.2 --).sub.n --O--].sub.m (where, R.sub.3 is hydrogen or methyl; n is an integer of 1 to 3; and m is an integer of 4 to 40);R.sub.2 is --(--CH--).sub.n --(where, n is an integer of 2 to 8); andR.sub.4 is hydrogen or methyl,wherein a mean chain length between cross-linked chains of the first macromolecules is adjusted to be 800-1800, and wherein a mean chain length between cross-linked chains of the second macromolecules is adjusted to be 800-1800, wherein occlusion time is improved in an ex vivo A-A shunt test compared to a reference IPM produced in the same manner, except having a mean chain length less than 800.