Blends/Alloys

The use of stabilisers (antioxidants) may, however, have adverse effects in that they inhibit cross-linking of the rubber. The influence of phenolic antioxidants on polystyrene-SBR alloys blended in an internal mixer at 180°C has been studied. It was found that alloys containing 1% of certain phenolic antioxidants were gel-deficient in the rubber phase.The gel-deficient blends were blotchy in appearance, and had lower flow rates compared with the normal materials, and mouldings were somewhat brittle. Substantial improvements in the impact properties were achieved when the antioxidant was added later in the mixing cycle after the rubber had reached a moderate degree of cross-linking. 

L. A. Utracki et al.. Polymer Alloys, Blends and lono-mers An overview in Multiphase Polymers Blends and lonomers (L. A. Utracki and R. A. Weiss, cds.), ACS Symposium Series No. 395, 1-35 (1989). 

Polyarylates are offered in several glass-reinforced versions with loading available up to 40%. Tile glass fibeis piovide liighei stiffness, improved tensile strength, and higher heat deflection temperatures. Polyarylates may also he mineral-filled and reinforced with other fibers, such as carbon. Alloys/blends with other polymers are also available. 

Alloyed blends consisting of epoxy-phenolic, epoxy-nylon, and epoxy-polysulfide adhesives... 

The first group, resins that are used primarily to toughen epoxy adhesive systems, is described in Chap. 8. This chapter focuses on the resinous modifiers that are used as alloy blends. Characteristics of commercially available epoxy alloy adhesives are presented in Table 7.1. Tensile shear and peel strengths that are typical of these hybrid adhesives are compared in Table 7.2. 

This section focuses on the modification of epoxy resins by blending with acrylonitrile butadiene (nitrile) resins. These are true alloyed blends since the nitrile rubber usually contains no groups that are normally reactive with epoxy groups. The nitrile molecules and the epoxy molecules intermingle as a blend to provide a single-phase alloy. If a large elastomer concentration is used, no phase separation will occur to form precipitates. 

Krause, S., Iskandar, M., Polymer Alloys, Blends, Blocks, Grafts, and... 

D. Klempner, K. C. Frisch, Eds., Polymer Alloys Blends, Blocks, Grafts,... 

ABS foam provides properties that include impact, heat, and chemical resistance low mold shrinkage rates good long-term dimensional stability and platability. Improved flammability characteristics are possible either by alloying (blending) with PVC or polycarbonate, or by... 

UTRACKI ETAL. Polymer Alloys, Blends, and Ionomers... 

Polymer Alloys—Blends, Blocks, Grafts, and Interpenetrating Networks" Klempner, D. Frisch, K. C, Eds. Plenum New York, 1977. 

Chromium oxide-containing catalysts are promising for partial oxidation of methane to synthesis gas (POM). TTie known preparation procedure of the foam monoliths from chromium oxide includes the use of gels prepared from alkoxides of metals forming matrix for the monolith catalysts [1]. In the present work, the preparation procedure of ceramometal monoliths from the metallic chromium and aluminum alloy blend has been described. The main stages of the preparation procedure and properties of the porous monolith have been studied. The catalysts performmce in the POM has been tested. 

Block polymers, owing to the tendency for formation of regular strucmres tailored by molecular design, are ideal models for compatibilized, two-phase polymer blends or alloys. Blends do show similar rheological behavior, e.g., yield, pseudoplasticity, thixotropy, structural rearrangements, but since the morphology is more difficult to control, the interpretation of data could present serious difficulties. 

The automotive industry started to use plastics in 1946. Since then, its content steadily increases (see Figure 16.4). Today, the plastics for automotive apphcations are dominated by polymer alloys, blends, and composites. The reason for it is the need for automotive parts to show a wide range of performance characteristics that are virtually impossible to meet using a single-component polymer. Thus, for example, in Saturn, front fenders and rear quarter panels are from PA/PPE, door outer skins are from PC/ABS, the bumper fascias are TPO, etc. 

Polymer alloying/blending see Allo5dng blends. Blending. .. 

At present, polymer alloys, blends, and composites consume over 80 wt% of all plastics. 

There are many alloys, blends and modifications of the basic materials, as well as new polymers that are constantly being Introduced. Time and testing of the various candidates will Identify those materials that will perform best. 

Table 9.9 Major Properties and Applications of Some Commercially Available Alloy/Blends... 

Alloy/Blends Trade Name/ Manufacturer Major Properties Applications... 

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