• Polymer(Korea)
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• v.24 no.1
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• pp.82-89
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• 2000

The blood compatibilities of PU/PVA polymer blends with different mixing ratios were evaluated using various methods, such as fibrinogen adsorption, plasma recalcification time, platelet adhesion, whole blood clotting time, and complement activation. In addition, PVA on the surface of the polymer blends was crosslinked by glutaraldehyde to restrain the mobility of PVA molecules for characterizing the effect of PVA in the polymer blends on blood compatibility. The fibrinogen adsorption on the polymer blends decreased with the increase of PVA amount in the polymer blends. The plasma recalcification times of the polymer blends with 10-50 wt% PVA were longer than those of PU, PVA, and polymer blends with higher amount of PVA. The morphological changes and adhesion of platelets on the polymer blends with 30-50 wt% PVA were less than those on the other materials. The blood clotting times and complement activation on the polymer blends with 30-50 wt% PVA were reduced, compared to the other materials. On the other hand, the blood compatibility of the crosslinked polymer blends was relatively decreased, compared to the non-crosslinked ones. According to these experimental results, the blood compatibility of the polymer blends with 30-50 wt% PVA was better than that of the other materials and such a blood compatibility of the polymer blends might be related to the mobility of PVA molecules on the surface.

• Macromolecular Research
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• v.14 no.3
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• pp.261-266
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• 2006

Blends of silicone rubber (VMQ) and liquid crystalline polymer (LCP) were prepared using a melt blending technique in the presence and absence of glass fiber and coupling agents. The effect of glass fiber and coupling agents on the thermal, dynamic mechanical, morphological pro-perties and cure characteristics of VMQ/LCP blends were studied. The vinyl silane coupling agent showed a significant effect on the above mentioned properties of VMQ/LCP blends by reacting at the interface between VMQ and LCP. The viscosity of the VMQ/LCP blends decreased with the addition of a coupling agent. A substantial improvement in storage modulus of VMQ/LCP blends was observed in the presence of glass fiber and coupling agents. However, as a coupling agent vinyl silane proved to be better than amine for the VMQ/LCP-glass-containing blends. The thermal stability of the pure silicone rubber was higher than those of the blends. This high thermal stability of silicone rubber was attributed to the Si-O-Si bonds. However, the thermal stability of the blends decreased further in the presence of a coupling agent, possibly due to a decrease in blend crystallinity.

• Korea-Australia Rheology Journal
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• v.14 no.3
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• pp.121-128
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• 2002

A series of thermoplastic polymers and their blends were melt-processed with high intensity ultrasonic wave in an intensive mixer. For the effective transfer of ultrasonic energy, an experimental apparatus was specially designed so that polymer melt can directly contact with ultrasonic horn. It was observed that significant variations in the rheological properties of polymers occur due to the unique action of ultrasonic wave without any aid of chemical additives. It was also found that the direct sonication on immiscible polymer blends in melt state reduces the domain sizes considerably and stabilizes the phase morphology of the blends. The degree of compatibilization was strongly affected by viscosity ratio of the components and the morphology was stable after annealing in properly compatibilized blends. It is suggested that ultrasound assisted melt mixing can lead to in-situ copolymer formation between the components and consequently provide an effective route to compatibilize immiscible polymer blends.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1023-1026
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• 2010

In this paper, rheological property of polymer blends in a confined geometry was investigated. The shear viscosity was measured in a capillary rheometer incorporated with a specially designed piston and three slit dies having 0.1, 0.2 and 0.5 mm in thickness. It was observed that the viscosity of polymer blends does not depend on the die size when the phase of polymer blends is a sea-island structure. However, when the phase of polymer blends is a co-continuous structure, the viscosity of the blends was dependent on the die size. By additional investigations, this result is attributed to the slip phenomenon between polymer phases in the blends.

• Macromolecular Research
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• v.11 no.5
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• pp.303-310
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• 2003

The phase behavior of binary blends of dimethylpolycarbonate-tetramethyl polycarbonate (DMPCTMPC) copolycarbonates and styrene-acrylonitrile (SAN) copolymers has been examined and then compared with that of DMPC/TMPC/SAN ternary blends having the same chemical components and compositions except that the DMPC and TMPC were present in the form of homopolymers. Both binary and ternary blends were miscible at certain blends compositions, and the miscible blends showed the LCST-type phase behavior or did not phase separated until thermal degradation temperature. The miscible region of binary blends is wider than that of the corresponding ternary blends. Furthermore, the phase-separation temperatures of miscible binary blends are higher than those of miscible ternary blends at the same chemical compositions. To explain the destabilization of polymer mixture with the increase of the number of component, interaction energies of binary pairs involved in these blends were calculated from the phase separation temperatures using lattice-fluid theory and then the phase stability conditions for the polymer mixture was analyzed with volume fluctuation thermodynamics.

• Elastomers and Composites
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• v.25 no.3
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• pp.203-210
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• 1990

The structure and properties of blends of ethylene-propylene-diene terpolymer(EPDM) and polyolefin blends have been investigated. The rheology and tensile properties of the EPDM/HDPE(high density polyethylene), EPDM/PP(polypropylene) binary and EPDM/PP/HDPE ternary blends were studied along with morphological analyses. Those properties were affected by preferential interaction of EPDM on HDPE, compared to that of EPDM on PP, for the binary blends. The preferetial interaction may stem from the molecular characteristics of EPDM to possess more ethylene units than propylene units in the elastomer. The EPDM played a role as compatibilizer for HDPE and PP in the EPDM/PP/HDPE ternary blends.

• Fibers and Polymers
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• v.1 no.2
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• pp.83-91
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• 2000

Thermotropic liquid crystalline polymer made up of poly(p-hydroxybenzoate) (PHB)-poly(ethylene terephthalate)(PET) 8/2 copolyester, poly(ethylene 2,6-naphthalate) (PEN) and PET were mechanically blended to pursue the liquid crystalline phase of ternary blends. Complex viscosities of blends decreased with increasing temperature and PHB content. DSC thermal analysis indicated that glass transition temperature (Tg) and melting temperature (Tm) of blends increased with increasing PHB content. Both tensile strength and initial modulus increased with raising PHB content and take-up speed of monofilaments. In the WAXS diagram, only PEN crystal reflection at 2Θ=$15.5^{\circ}C$ appeared but PET crystal reflection was not shown in all compositions. The degree of transesterification and randomness of blends increased with blending time but sequential length of both PEN and PET segment decreased.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.51-56
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• 2004

Conductive polymer blends and composites are widely used for different safety application such as electrostatic charge dissipation(ESD), electromagnetic interference(EMI) shielding, electrostatic prevention and safety chemical sensor. In order to prepare a impedance-type humidity sensor that is durable at high humidities and high temperature, electically conductive polymer blends based on diallyldimethylammonium chloride(DADMAC) and epoxy were prepared in this study. The polymer blends type conductive ionomer exhibits reaction each other DADMAC and epoxy in FT-IR and DSC analysis. The blends material was traced by new peak at 1600cm-1 and appeard improvement of thermal resistance by melting point shift. Alumina substrate was deposited a pair of gold electrodes by screen printing. The blend material were spin-coated with a thin film type on the surface of alumina substrate. The polymer bleld type sensor exhibits a linear impedance increasing better than DADMAC coated humidity sensor. Also it shows good sensitivity, low hysteresis and durability against high humidity.

• Elastomers and Composites
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• v.6 no.2
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• pp.73-79
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• 1971

As a series of the studies of EPDM-Polymer blends, the experiments are concentrated to the investigation of the physical properties of the EPDM-SBR blends. The results are shown as follows: 1. Tensile strength decreased with increase in EPDM contents and the decreasing value was good results than NR blending. 2. It was found that the aging were much improved after blending and experiments data was good results than NR blending.

• Polymer(Korea)
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• v.24 no.5
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• pp.682-689
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• 2000

The information related to the interaction energy between repeat units is essential for the production of useful polymer blends via molecular structure design. Based on the interaction energies obtained here, a method for the fabrication of miscible blend was suggested. An investigation related to the equilibrium phase behavior of polymer blends of various polycarbonates with various polymethacrylates was performed and then based on the obtained interaction information miscible polymer blends were produced by controling molecular structure of polymer. Binary interaction energies between repeat units were calculated from the lower critical solution temperature-type phase boundary using an equation of state combined with binary interaction model.