Impact Modified Blends

PC/PEST/elastomer/P/ienoxy impact modified blends Liu Giles, 1986... 

Poly(styrene-co-maleic anhydride) (SMA) is frequently mixed with SAN before the reactive blending with PA [Takeda and Paul, 1992]. Much attention has been paid to morphology control during the reactive processing [Serpe et al, 1990 Campbell et al., 1990 Willis and Favis, 1990]. Frequently, a third polymer is added as a com-patibilizer for binary systems, e.g., MA-grafted SEES to compatibilize (and impact-modify) blends of PE with PET [Carte and Moet, 1993]. 

For impact-modified blends (Xenoy 1200 and 5720, Stapron E), screw speed should be set at minimum, as low as possible (less than 50 rpm), just sufficient to assure a reasonable cycle time. Melt temperature should be kept as low as possible, without binding the screw. When temperature control is critical, as is the case here, the acmal melt temperature should be checked with a pyrometer or digital thermometer, rather than relying on barrel set points. The material runs best in thick parts with oversized gates. Injection speed of 25 mm/sec is suggested. When running a large shot (>70% of machine capacity), a flat or reverse barrel heat profile may help to convey the melt. 

Table 15.11. Commercial acrylic/impact modifier blends vs. acrylic...

Figure 15.6. Morphology of typical Polyamide/impact modifier blends — TEM., Phosphotungstic acid stain, top — PA-6/ethylene copolymer/ionomer blend (21,000X) bottom — PA-6/maleated EPR (3 1) blend (30,000X).

Nylon 6,6. Nylon 6,6 appears in automotive applications mostly in impact-modified, blended, and filled (mostly glass reinforced, with or with out impact modifiers) form. Impact modification of nylon 6,6 is of significant commercial importance, especially for automotive uses. Typical applications include fasteners for interior and exterior components, a host of connectors, holding fixtures, and radiator end caps, and a fairly common application is for air intake manifolds (Fig. 9.4). These applications rely on the ductility and toughness of impact-modified nylon 6,6 as a mechanism to connect assemblies or join components. 

PC/PES T /slsistomsr/phenoxy Impact-modified blends Liu and Giles 1986... 

Table 19.31 Properties of some ctnnmercial polyoxymethylene/impact modifier blends ...

FiberfilTN Polyamide-6, 12 impact modified blends containing PO GF reinforced or not Akzo/DSM... 

The evolution of technology of these impact modified blends has led to the current Xenoy PC/PBT blends with izod notched impact strength, high ductility down to minus 30 mainly used for off-line painted bumper applications (fig 6). 

PPE/PA/impact modifier blends are reactively compounded, frequently with glass fiber reinforcements. They offer a unique combination of HDT, impact strength, dimensional stabihty and chemical resistance. These alloys find applications in the automotive industry (e.g., fenders, panels, wheel covers), industrial uses, garden tools, etc. 

Impact modified blends UP resin laminates VE resin laminates... 

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