Synergistic improvement

Poly(ethyl methacrylate) (PEMA) yields truly compatible blends with poly(vinyl acetate) up to 20% PEMA concentration (133). Synergistic improvement in material properties was observed. Poly(ethylene oxide) forms compatible homogeneous blends with poly(vinyl acetate) (134). The T of the blends and the crystaUizabiUty of the PEO depend on the composition. The miscibility window of poly(vinyl acetate) and its copolymers with alkyl acrylates can be broadened through the incorporation of acryUc acid as a third component (135). A description of compatible and incompatible blends of poly(vinyl acetate) and other copolymers has been compiled (136). Blends of poly(vinyl acetate) copolymers with urethanes can provide improved heat resistance to the product providing reduced creep rates in adhesives used for vinyl laminating (137). 

When two antioxidants are used together, a synergistic improvement in activity usually results. Synergism can arise from three combinations (1) homosynergism — two chemically similar antioxidants (for instance, two hindered phenols) (2) autosynergism — two different antioxidants functions that are present in the same molecule (3) heterosynergism — the cooperative effect between mechanistically different classes of antioxidants, such as the combined effect of primary and secondary antioxidants. Thus, combinations of phenols and phosphites are widely used to stabilize synthetic rubbers. 

Synergistic Improvement in Modulus, Tear Strength, and Hardness of Blends... 

Thus the integrated application of structure-based design and combinatorial chemical technologies can produce synergistic improvements in the effi-... 

Fundamental studies of blends of polycarbonate with aciyloni-trile-buladiene-styrene (ABS) indicate that the presence of ABS greatly decreases the melt viscosity in the blend, enhancing processibility. A synergistic improvement of the notched impact strength at low temperature is also seen for polycarbonate-ABS blends. 

Titanium or beryllium oxide also provides a degree of improvement in thermal conductivity to epoxy systems. Magnesium oxide and aluminum oxide have also been commonly used for this purpose, although the degree of improvement is not as great as with the fillers discussed above. The effect of various fillers on the thermal conductivity of cured adhesive is shown in Fig. 9.6. The incorporation of metal fibers with metal powders has been shown to provide synergistic improvement to the thermal conductivity of adhesive systems,... 

Lead oxide in conjunction with antimony trioxide showed a synergistic improvement in performance , as shown in Table 7.2. Bartz showed a marked improvement in wear life for a three-component mixture of molybdenum disulphide, graphite and antimony tetrasulphide. Like those of Centers , his tests were carried out with unburnished/non-run-in films, against an uncoated block, and may not be representative of practical engineering situations. 

Isotropic liquid detergents containing a soil release polymer and an antiredeposition enhancer (PVP, PVPNO) delivering a synergistic improvement in soil antiredeposition... 

Regarding the catalytic essays, the total oxidation of methane has been studied. The light-off temperatures associated to 50% conversion of methane on the C-LS, CT-80/20-LS and T-LS were found to be 778 K, 667 K and 692 K, respectively. This result, also in agreement with those reported above, gives us a further indication of the synergistic improvement of performance achieved in the mixed oxide with reference to that exhibited by the ceria and terbia mixed oxides. 

Polymer blends can fill the cost-performance gaps in the existing commercial polymers. Several properties can be uniquely combined in a blend that a single resin often cannot provide. In some cases, synergistic improvements in properties such as toughness and heat resistance are achievable. 

Despite some environmental concerns, halogenated flame retardants still play an important role. With the exception of a few chlorinated products (e.g., chlorinated paraffins), these flame retardants contain usually molecules with several bromo groups (Fig. 11.18). Bromo compounds are active during combustion in the gas phase, whereas HBr reacts with OH and H radicals under formation of less reactive halogen radicals. The flame retardancy of bromo compounds is often synergistically improved by the addition of antimony oxide Sb203. 

T. Yang, N. Zhou, Y. Zhang, W. Zhang, K. Jiao, and G. Li, Synergistically improved sensitivity for the detection of specific DNA sequences using polyaniline nanofibers and multi-walled carbon nanotubes composites. Biosens. Bioelectron., 24, 2165—2170 (2009). 

Risse, S., Kussmaul, B., Kr Ger, H., Kofod, G., 2012. Synergistic improvement of actuation properties with compatibilized high permittivity filler. Adv. Eunct. Mater. 22,3958-3962. 

An AO combined with a metal deactivator or chelator provides critical synergistic Improvements against oxidation In LTHA. 

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