• Elastomers and Composites
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• v.31 no.5
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• pp.341-346
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• 1996

The fracture mechanics investigation of the thermoplastic vulcanizates(TPV) from EPDM and PP/Ionomer ternary blends was performed in terms of the J-integral by measuring fracture energy via the locus method. The TPV from ternary blends consisting of EPDM, PP and ionomer were prepared in a laboratory integral mixer by blending and vulcanizing simultaneously. Vulcanization was performed with dicumyl peroxide (DCP) and the composition of EPDM and PP was fixed at 50/50 by weight. Two kinds of poly(ethylene-co-methacrylic acid) (EMA) lonomers were used. The J-integral values at crack initiation, Jc, of the dynamically vulcanized EPDM and PP/EMA Ionomer ternary blends were affected by the cation types $(Na^+\;or\;Zn^{2+})$ and contents(5-20wt%) of the added EMA Ionomers. The ternary blend containing 20wt% zinc-neutralized EMA Ionomer and 1.0phr DCP showed the highest Jc values of the blends.

• Polymer(Korea)
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• v.25 no.6
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• pp.840-847
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• 2001

The crystallization characteristics of metallocene linear low density polyethylene (m-LLDPE)/linear low density polyethylene (LLDPE) blends were investigated. The effect of blending on the induction time for crystallization, spherulites growth rate, and maximum size of spherulites was mainly considered in this study. The formation of separate crystal which is well known crystallization behavior in LLDPE/LDPE blend was not found in m-LLDPE/LLDPE blends. The blending m-LLDPE to LLDPE caused the dramatic decrease in the induction time of m-LLDPE/LLDPE blends but it seems that the blend composition shows less effect on the induction time. Lower branching number in m-LLDPE resulted in the increasing of spherulites growth rate and the maximum size of spherulites is depend upon both the induction time and spherulites growth rate of LLDPE component affected by m-LLDPE.

• Macromolecular Research
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• v.10 no.2
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• pp.91-96
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• 2002

To explore the effects of intramolecular interactions within the copolymer on the phase separation behavior of polymer blends, copolymers having two different types of intramolecular interactions, i.e., intramolecular repulsion and intramolecular attraction were prepared . In this study, poly(styrene-co-methylmethacrylate) (P(S-MMA)) having intramolecular repulsion caused by positive interaction between styrene and MMA and poly(styrene-co-ethyl-methacrylate) (P(S-EMA)) and poly(styrene-co-cyclohexylmethacrylate) (P(S-CHMA)) having intramolecular attraction caused by negative interaction between styrene and methacrylate were blended with tetramethyl poly-carbonate (TMPC). The phase behavior of blends was examined as a function of copolymer composition and blend composition. TMPC formed miscible blends with styrenic copolymers containing less than certain amount of methacrylate. The phase separation temperature of TMPC blends with copolymer such as P(S-MMA) and P(S-EMA), first increases with methacrylate content, goes through a maximum and then decreases just prior to the limiting content of methacrylate for miscibility, while that of TMPC blends with P(S-CHMA) always decreases. The calculated interaction energy for TMPC-P(S-EMA) pair is negative and monotonically increases with EMA content of the copolymer. Such behavior contradicted the general notion that systems with more favorable energetic interactions have higher LCST, The detailed inspection of the lattice-fluid theory related to the phase behavior was performed to explain such behavior.

• Fibers and Polymers
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• v.1 no.1
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• pp.32-36
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• 2000

An alternative strategy to .educe the percolation threshold of carbon black (CB) in polymer blends was investigated using random copolymer ternary blends of polystyrene (PS), poly(methyl methacrylate)(PMMA), and a styrene-methyl methacrylate random copolymer (SMMA). The target morphology was to selectively locate CB particles in the encapsulating layer of SMMA during melt mixing. The CB used in this study is BP-2000 from Cabot and has a strong selective affinity to PS. Even when the CB was premixed with SMMA, it moves to the PS phase during the melt mixing. However, we also observed the CB particles located at the interface between SMMA and PS phases. Through this study it is found that the interaction between polymers and CB particles is critical for selectively localizing CB particles in multi-component polymer blends. Although appropriate processing condition may retard the movement of CB particles to the polymer phase with affinity, it cannot prevent it completely and locate them to the SMMA phase, which is not thermodynamically favored. To locate CB particles in an encapsulating layer of ternary polymer blends, first of all, polymers forming it should have selective affinity to CB.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.343-348
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• 2018

Each of the two polycarbonates (PC) of different molecular weights was blended with acrylonitrile-butadiene-styrene (ABS) under high-shear rate processing to afford PC/ABS. Sizes of ABS dispersed phases and mechanical properties of PC/ABS blends were investigated and high-shear rate processing of PC/ABS was carried out by changing screw speed and processing time. Prepared specimens were examined by scanning electron microscope (SEM) to observe morphology changes. Sizes of ABS dispersed phases in PC/ABS blends were observed to decrease gradually as screw speeds increased. Tensile strengths and elongations of specimens were investigated by universal testing method (UTM) to study the influence of molecular weight of PC exerting on PC/ABS blends. As a result, PC1/ABS blends (PC1: higher molecular weight PC) exhibited more strengthened properties than PC2/ABS (PC2: lower molecular weight PC). The tensile strength of PC1/ABS showed an increasing tendency when the screw speed increased, and the elongation did not show a significant decrease, but increased slightly with increasing shear time at a constant screw speed of 1000 rpm.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.78-83
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• 2006

A simplex-lattice mixture design was applied to blend three varieties of rice; Ilpum (IP), Goami2 (G2) and Baegjinju (BJJ) all of which have very different physicochemical properties from one another. G2 and BJJ are mutant rice developed from IP. Increasing G2 portions in a rice blend increases indigestible carbohydrate contents. Blending at least 33.3% of G2 to either IP or BJJ increased indigestible carbohydrates, which were approximately $3.55{\pm}1.31\;to\;4.57{\pm}0.37$(g/100 g), respectively. Consumers rated higher than 6.0 (=like slightly) for the IP alone and binary blends of IP and BJJ, whereas less than 5.0 (=dislike moderately) for the blends containing G2 rice, indicating that consumers would not accept rice blends containing higher G2 portions. However, although blends with G2 were given lower consumer ratings, a rice blend with G2 could have health benefits in terms of nutritional and functional properties due to the higher indigestible carbohydrate contents.

• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.361-366
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• 2016

The physicochemical characteristics of fresh noodles made with blends of low-protein wheat flour and barley byproduct (BBP, $250{\mu}m$) were investigated. The crude protein contents (PC) of flour from Goso and Backjoong cultivars were 7.91% and 7.67%, respectively. PC and ${\beta}$-glucan contents from the BBP were 14.10% and 3.11%, respectively, which were higher than those in wheat flour. The water-holding capacity (WHC) of various blends was increased as a function of BBP but not gluten contents. Goso flour had the highest starch content (78.68%), with peak and final viscosities of 3,099 and 3,563 cp, respectively. Peak and final viscosities, trough, breakdown, and setback of the blends were decreased with the addition of BBP. Noodles made with Backjoong had the highest thickness score, while the hardness of noodles made with blends of Goso or Backjoong and 20% BBP were similar to those made from wheat flour only. The WHC of the samples was strongly correlated with PC, crude fiber, and ${\beta}$-glucan. The PC was not correlated with final viscosity, setback, thickness, hardness, gumminess, or chewiness.

• Polymer(Korea)
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• v.24 no.1
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• pp.113-123
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• 2000

Poly(p-hydroxybenzoate) (PHB)/poly(ethylene terephthalate) (PET) 8/2 thermotropic liquid crystalline copolyester, poly(ethylene 2,6-naphthalate) (PEN) and PET were mechanically blended to obtain the pseudo liquid crystalline (LC) phase of ternary blends. The torque values of blends with increasing PHB content were abruptly decreased above 40 wt% of PHB content, because the melt viscosity of ternary blends decreased. Tensile strength and initial modulus of blends containing above 30 wt% PHB were improved with increasing PHB content. Tensile strength and modulus of fiber were increased with PHB contents and take-up speed. Degree of transesterification and randomness of blends were increased with blending time. The blend of 40 wt% PHB was shown pseudo LC phase in the polarized optical photographs. Crystallinity of PHB/PEN/PET ternary blend were increased with PHB content.

• Korea-Australia Rheology Journal
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• v.13 no.4
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• pp.189-196
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• 2001

The phase morphology is an important factor in the rheology of immiscible polymer blends. Through its size and shape, the interface between the two phases determines how the components and the interface itself will contribute to the global stresses. Rheological measurements have been used successfully in the past to probe the morphological changes in model blends, particularly for dilute systems. For more concentrated blends only a limited amount of systematic rheological data is available. Here, viscosities and first normal stress differences are presented for a system with nearly Newtonian components, the whole concentration range is covered. The constituent polymers are PDMS and PIB, their viscosity ratio can be changed by varying the temperature. The data reported here have been obtained at 287 K where the viscosities of the two components are identical. By means of relaxation experiments the measured stresses are decomposed into component and interfacial contributions. The concentration dependence is quite different for the two types of contribution. Except for the component contributions to the shear stresses there is no clear indication of the phase inversion. Plotting either the interfacial shear or normal stresses as a function of composition produces in some cases two maxima. The relaxation times of these stresses display a similar concentration dependence. Although the components have the same viscosity, the stress-component curves are not symmetrical with respect to the 50/50 blend. A slight elasticity of one of the components seems to be the cause of this effect. The data for the more concentrated blends at higher shear rates are associated with a fibrillar morphology.

• 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.