An Investigation into Anionic Polymerization of Styrene Sulfonic Acid Derivatives and Blood Platelet Reactivity with Two-Phased Polymers Containing Polypropyl-p-styrene Sulfonate

Abstract

<p>This thesis reports on the synthesis, purification and anionic polymerization of several derivatives of styrene sulfonic acid and on the block copolymerization of propyl-p-styrene sulfonate with isoprene and styrene. The domain morphology of polyisoprene:polypropyl-p-styrene sulfonate block copolymers and a one to one blend of the corresponding homopolymers are defined, and blood platelet reactivity with the block copolymers, the respective homopolymers and the blend is investigated.</p> <p>p-Styrene sulfonamide terminates the anionic initiator (sodium naphthalene) probably by amidolysis. Methyl- and isopropyl-p-styrene sulfonates polymerize but proper purification is extremely difficult. Propyl-p-styrene sulfonate polymerizes, but propagation is halted without termination of the anions after only a relatively low molecular weight polymer is formed. Possible reasons for the formation of these apparently dormant anions is considered in some detail.</p> <p>The sulfonate-styrene-sulfonate and a broad range of sulfonate-isoprene-sulfonate triblock copolymers were prepared with a range of phase morphology features with dimensions of the order of 100Å. They and the respective homopolymers are all found to induce moderate and indistinguishable in vitro platelet responses as determined by radioactive labeling of platelets and by electron microscopy. In contrast, however, the blend of homopolymers which has phase morphology features with dimensions of the order of magnitude of platelet dimensions is shown to induce nonrandom clustering of adherent platelets. It is possible that morphologies with these dimensions may influence platelet thrombus propagation over the surface.</p>