POLY(O-ACYL HYDROXY L-PROLINE) .2. WETTING CHARACTERISTICS AND BLOOD-CLOTTING ON SURFACES OF POLY O-ACETYL, BUTYRYL, HEXANOYL, DODECANOYL, AND BENZOYL HYDROXY L-PROLINE

Poly O-acetyl, butyryl, hexanoyl, dodecanoyl, and benzoyl hydroxy L-proline (poly left bracket O-acyl Hyp right bracket s) were evaluated as materials for blood contact by means of contact angle and blood clotting time measurements. Critical surface tensions obtained from Zisman plots for all materials were 22-29 dyn/cm, suggesting that these materials may exhibit good blood compatibility. The materials showed remarkable wetting differences that were dependent on the type of acyl group attached to Hyp. The values of the dispersion and non-dispersion components of the surface tension for poly(O-hexanoyl Hyp) and poly(O-dodecanoyl hyp) were very close to those obtained for glutaraldehyde-treated umbilical cord vessels. The blood clotting times on the respective polymer surfaces, obtained by using the kinetic method, were normalized to those of control glass and siliconized glass surfaces. All the poly(O-acyl Hyp)s surfaces showed longer clotting times than those of the poly(L-proline) and glass surfaces.