Novel blood-compatible waterborne polyurethane using chitosan as an extender

A series of novel block polymers of polyur- ethane (PU) and chitosan have been prepared in two steps. The first step is the preparation of PU prepolymer, obtained from polytetramethylene oxide glycol (PTMO, Mn 5 1000), isophrone diisocyanate (IPDI), and 2,2 0 -dimethylol propionic acid (DMPA), followed by ionizing PU prepoly- mer with triethylamine (TEA). The second step involves PU chain-extended by water-soluble chitosan of low mo- lecular weight (Mn 5 5000) by self-emulsion polymeriza- tion method. The sizes of the latex particles, morphology, and copolymer architecture have been characterized by dynamic light scattering (DLS), general tensile test, infra- red spectroscopy (IR), surface contact angle measurement, and transmission electron microscopy (TEM). Furthermore, it shows that the addition of chitosan remarkably increases anticoagulative property of PU elastomers confirmed by the recalcification time. 2008 Wiley Periodicals, Inc. J Appl Polym Sci 109: 240-246, 2008