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Blood-contacting properties of polypropylene surfaces with different crystalline states at the surface layer were examined in terms of plasma protein adsorption and changes in cytoplasmic free Ca2+ levels in platelets. Though the wettability of polypropylene surfaces was almost constantly independent from the surface layer crystallinity and interlamellar(More)
In this work, the relationship between the unsaturated chain end group content and the thermal oxidative degradation rate was systematically studied with binary polymer blends of isotactic polypropylene (iPP) with and without the unsaturated chain end group. The iPPs with and without the unsaturated chain end group were synthesized by a metallocene catalyst(More)
In propylene polymerization with MgCl(2) -supported Ziegler-Natta catalysts, it is known that the reduction of TiCl(4) with alkylaluminum generates Ti(3+) active species, and at the same time, leads to the growth of TiCl(x) aggregates. In this study, the aggregation states of the Ti species were controlled by altering the Ti content in a TiCl(3) /MgCl(2)(More)
Biodegradable hydrogels consisting of oligopeptide-terminated poly(ethylene glycol) (PEG) and dextran (Dex) with an interpenetrating polymer network (IPN) structure were prepared as models of novel biomaterials exhibiting a double-stimuli-response function. The IPN-structured hydrogels were synthesized by sequential cross-linking reaction of(More)
A TiCl4/ethylbenzoate/MgCl2 Ziegler-Natta catalyst was pretreated with chemically different poisoning compounds to investigate their effects on the catalyst activity and stereospecificity for propylene polymerization. The poisoning power on the activity was in the order of methanol > acetone > ethyl acetate. A kinetic analysis using the stopped-flow method(More)
A series of aliphatic polyamide (nylon) sheets with different draw ratios were prepared and their blood-contacting properties examined in relation to the bulk and surface characteristics. Increases in both the molecular orientation and crystallinity were observed with increasing draw ratio. Their surface wettability slightly decreased with draw ratio,(More)
Polypropylene surfaces with a particular crystalline-amorphous microstructure have been demonstrated to reduce protein adsorption and platelet activation. Such blood-contacting properties may be affected by the crystalline-amorphous microstructure of the surfaces, although wettability such as dynamic contact angles and surface free energy components were(More)
Grafting terminally functionalized polypropylene (PP) to nanofillers provides well-defined PP-based nanocomposites plausibly featured with a physical cross-linkage structure. In this paper, a series of PP-grafted silica nanoparticles (PP-g-SiO 2) were synthesized by varying the number of grafted chains per silica particle, and influences of the number and(More)
Rational catalyst design necessitates fundamental knowledge on the structure-performance relationship, while the synthetic throughput for heterogeneous Ziegler-Natta olefin polymerization catalysts has long prevented the acquisition of a statistical database. In this contribution, an in-house reactor system was developed to realize the parallel synthesis of(More)
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