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Polyethylene interfacial tension

A zero or near-zero contact angle is necessary otherwise results will be low. This was found to be the case with surfactant solutions where adsorption on the ring changed its wetting characteristics, and where liquid-liquid interfacial tensions were measured. In such cases a Teflon or polyethylene ring may be used [47]. When used to study monolayers, it may be necessary to know the increase in area at detachment, and some calculations of this are available [48]. Finally, an alternative method obtains y from the slope of the plot of W versus z, the elevation of the ring above the liquid surface [49]. [Pg.23]

Compatibility and various other properties such as morphology, crystalline behavior, structure, mechanical properties of natural rubber-polyethylene blends were investigated by Qin et al. [39]. Polyethylene-b-polyiso-prene acts as a successful compatibilizer here. Mechanical properties of the blends were improved upon the addition of the block copolymer (Table 12). The copolymer locates at the interface, and, thus, reduces the interfacial tension that is reflected in the mechanical properties. As the amount of graft copolymer increases, tensile strength and elongation at break increase and reach a leveling off. [Pg.644]

ATBN - amine terminated nitrile rubber X - Flory Huggins interaction parameter CPE - carboxylated polyethylene d - width at half height of the copolymer profile given by Kuhn statistical segment length DMAE - dimethyl amino ethanol r - interfacial tension reduction d - particle size reduction DSC - differential scanning calorimetry EMA - ethylene methyl acrylate copolymer ENR - epoxidized natural rubber EOR - ethylene olefin rubber EPDM - ethylene propylene diene monomer EPM - ethylene propylene monomer rubber EPR - ethylene propylene rubber EPR-g-SA - succinic anhydride grafted ethylene propylene rubber... [Pg.682]

The surface rigidity and lowering of interfacial tension of a drop-soluble surfactant will cause a smaller drop to be formed from a specific size of nozzle. The terminal velocity is lowered in a manner independent of drop size. Figure 17 shows the results of experiments with drops of chlorobenzene in water. Formed from a nozzle made of a piece of f-in. brass pipe, the drop of high-purity chlorobenzene fell at 13.1 cm./sec. Ten cm. of TMN (trimethyl nonyl ether of polyethylene glycol supplied by... [Pg.82]

Abbreviations y x AFM AIBN BuMA Ca DCP DMA DMS DSC EGDMA EMA EPDM FT-IR HDPE HTV IPN LDPE LLDPE MA MAA MDI MMA PA PAC PB PBT PBuMA PDMS PDMS-NH2 interfacial tension viscosity ratio atomic force microscopy 2,2 -azobis(isobutyronitrile) butyl methacrylate capillary number dicumyl peroxide dynamic mechanical analysis dynamic mechanical spectroscopy differential scanning calorimetry ethylene glycol dimethacrylate ethyl methacrylate ethylene-propylene-diene rubber Fourier transform-infra-red high density polyethylene high temperature vulcanization interpenetrating polymer network low density polyethylene linear low density polyethylene maleic anhydride methacrylic acid 4,4 -diphenylmethanediisocyanate methyl methacrylate poly( amide) poly( acrylate) poly(butadiene) poly(butylene terephtalate) poly(butyl methacrylate) poly(dimethylsiloxane) amino-terminated poly(dimethylsiloxane)... [Pg.112]

JorzikU, Wolf BA (1997) Reduction of the interfacial tension between poly(di-methylsiloxane) and polyethylene oxide) by block copolymers Effects of molecular architecture and chemical composition. Macromolecules 30(16) 4713-4718... [Pg.142]

A number of water-soluble polymers will cause phase separation when present together at concentrations of a few percent. The most widely used polymers are polyethylene glycol (PEG) and dextran. Proteins, other macromolecules, and cell components such as mitochondria distribute in the phases or collect at the interface. Proteins are destabilized at organic solvent/water interfaces, but when each solvent is water, the interfacial tension is negligible. Some salts such as potassium phosphate will also induce phase separation when a polymer is present, but the salt concentration must be high. Two-phase aqueous systems provide a mild method for purification of proteins, and scale-up to large volumes presents no engineering problems. The polymers... [Pg.1900]

The cross-axis CPC produces a unique mode of planetary motion, such that the column holder rotates about its horizontal axis while revolving around the vertical axis of the centrifuge.This motion provides satisfactory retention of the stationary phase for viscous, low-interfacial tension, two-phase solvent systems, such as aqueous-aqueous polymer phase systems. Our previous studies demonstrated that the cross-axis CPC equipped with a pair of multiplayer coils or eccentric coil assemblies in the off-center position was very useful for the separation of proteins with polyethylene glycol-potassium phosphate solvent systems.The apparatus is also useful for the separation of highly polar compounds such as sugars,hippuric acid, and related compounds, which require the use of polar two-phase solvent systems. [Pg.239]

The method, however, fails to retain viscous, low interfacial tension polymer phase systems such as polyethylene glycol (PEG)-dextran systems due to its intensive mixing effect which tends to produce emulsification, resulting in carryover of the stationary phase. This problem is largely eliminated by the crossaxis CPC described below. [Pg.408]

Harrison KL, Johnston KP, Sanchez IC. Effect of surfactants on the interfacial tension between supercritical carbon dioxide and polyethylene glycol. Langmuir 1996 12 2637-2644. [Pg.242]

Blending within the family of PO has, however, been more common [Plochocki, 1978]. Although they are usually immiscible with each other, there exists some degree of mutual compatibihty between them. The similarity of their hydrocarbon backbones and the closeness of their solubility parameters, although not adequate for miscibility, accounts for a relatively low degree of interfacial tension. Eor example, the solubility parameters of polyethylene, polyisobutylene, ethylene-propylene rubber and polypropylene are estimated to be 16.0, 15.4,... [Pg.1032]

In addition to w/c microemulsions, o/c microemulsions may be formed for systems with strong surfactant adsorption. The area occupied by PFPE-C00 NH4 at the interface between 600 molecular weight polyethylene glycol (PEG) md CO2 is 440 per molecule based upon measurement of the interfacial tension versus surfactant concentration [21]. This surface coverage is sufficient for microemulsion formation as was verified with phase behavior measurements. Only 0.55 wt% of 600 molecular weight polyethylene glycol is soluble in CO2 at 45 °C and 300 bar. With the addition of 4wt% PFPE-C00 NH4 surfactant, up to 1.8 wt% is solubilized. The additional PEG resides in the core of the microemulsion droplets, consistent with the prediction from the adsorption measurement. [Pg.135]

Harrison, K. L. Johnston, K. P. Sanchez, I. C. Effect of Surfactants on the Interfacial Tension between Supercritical Carbon Dioxide and Polyethylene Glycol. Langmuir 1996, 12(11), 2637-2644. [Pg.442]

Yet another interesting conclusion may be derived from the two-liquid adhesion tension data of Bascom and Singleterry [11] which are recorded in Table III. If Equation 17 is applied to each of two different hydrocarbon liquids, the difference between the two solid-liquid interfacial tensions is just the (negative) difference between the respective two-liquid adhesion tensions. Thus, from the values given in Table III, the solid-liquid tension for isopropyl biphenyl is 8 dynes per cm. greater than that for n-decane. This difference is the same for both oolytetra-fluoroethylene and polyethylene. [Pg.173]

Reaction with vinyl acetate [81], hydroxypropylation [82], reactions with styrene [83], with ethylene glycol and other glycols giving rise to glucosides [63,84] or with acrylamide monomer [85,86] have also been described. Reactive extrusion is also used to decrease the melt viscosity and decrease the interfacial tension of TPS-based blends [76]. Ning et al. [74] studied the effect of adding citric acid on TPS and LLDPE, via a single-step reactive extrusion. The authors showed improvements in the compatibilization and the mechanical properties and shifts of polyethylene peaks observed by FTIR. [Pg.93]

Hydrophilic coatings have also been popular because of their low interfacial tension in biological environments [Hoffman, 1981]. Hydrogels as well as various combinations of hydrophilic and hydrophobic monomers have been studied on the premise that there will be an optimum polar-dispersion force ratio which could be matched on the surfaces of the most passivating proteins. The passive surface may induce less clot formation. Polyethylene oxide coated surfaces have been found to resist protein adsorption and cell adhesion and have therefore been proposed as potential blood compatible coatings [Lee et al., 1990a]. General physical and chemical methods to modify the surfaces of polymeric biomaterials are listed in Table 40.7 [Ratner et al., 1996]. [Pg.645]

Wu, S., Surface and interfacial tensions of polymer melts I. Polyethylene, polyisobutylene, and polyvinyl acetate, J. Colloid Interface ScL, 31, 153 (1969). [Pg.356]


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See also in sourсe #XX -- [ Pg.617 ]




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Interfacial tension

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