Controlling the morphology of polyurethane/polystyrene interpenetrating polymer networks for enhanced blood compatibility

Abstract

Polyurethane (PU)/polystyrene (PS) IPNs were simultaneously synthesized at 80°C, controlling the reaction kinetics to change the morphology. Polymerization kinetics of styrene was controlled by the content of initiator, and that of polyurethane by the catalyst concentration. The effect of the initiator and the catalyst on the polymerization rate was analyzed by NMR spectroscopy and FTIR. Gelation time was also measured by using the advanced rheometric expansion system (ARES). Samples with sea-and-island morphology were obtained, when the polymerization rate of PS was relatively slow, and the phase separation time was long. When the polymerization rate of PS was relatively fast, and the phase separation time was short, cocontinuous morphology was obtained. The degree of phase separation and surface roughness decreased, as the rate of PU network formation was increased, and the phase-continuity was increased. The in vitro blood-compatibility tests showed that the surface roughness was an important factor on the adsorption of fibrinogens and platelets. A large amount of fibrinogens and platelets were adsorbed on the relatively rough surface of samples showing sea-island morphology.

Effect of PEO Grafts on the Surface Properties of PEO-Grafted PU/PS IPNs: AFM Study

“…The IPN surfaces developed microphase-separated structure with the same likelihood as the amphiphilic diblock copolymers did previously, but the hydrophilic phase and hydrophobic phase interlocked, and thus structural stability and insensitivity to environmental change would be expected. Recently, we introduced mobile hydrophilic pendant PEO chains on the IPNs to enhance the blood compatibility under conventional physiological conditions, and we reported that the grafting of mobile pendant PEO chains on the IPN suppressed platelet adhesion and protein adhesion on the IPN due to the “molecular cilia effect” of the pendant chains. − In this study, surface compositional mapping was attempted with AFM images of PEO-grafted PU/PS IPNs by using recently developed AFM techniques. We also investigated the effect of hydrophilic PEO pendant chains on the local elasticity and surface energy of the IPN by using the “force−distance analysis” of AFM.…”

Development of Styrene-Grafted Polyurethane by Radiation-Based Techniques

“…The surface morphologies of unmodified PU were almost smooth but became rougher with increasing styrene content and radiation dose [5,6]. The surface morphology of the SPU composites were dependent on the styrene content and radiation dose [18,19].…”

“…PU has been used in the production of flexible foams for beds, automobiles and sofas, rigid foams used as an insulating material of refrigerators and buildings, paints, adhesives, spandex fibers, and thermoplastic polyurethane [5,6,7]. PU is the fifth most commonly used polymer in consumer markets, following PP, PE, PVC, and PS, and is the most commonly used polymer in thermosetting resins.…”

Exfoliated Poly (styrene-co-urethane) Grafted - Polymethylmethacrylate /Layered Double Hydroxide Nanocomposite Synthesized by Metal Catalyzed Living Radical Polymerization and Solvent Blending Method

“…On the other hand, polyurethane (PU) has unique affect resistance, hydrolytic, thermal stability, excellent mechanical strength, chemical and physical resistance. Polyurethane has been used in automobiles, coating, variable foams for floors, composites, and stiff foams used as an insulating polymeric material of refrigerators, reaction molding fibers, plastics, paints, sticky, buildings, and thermoplastic elastomer [5][6][7].…”