Properties of SPS/Nylon blends

The vast majority of SPS/nylon blends to date have been formulated using nylon 6 and nylon 6,6. nylon 6 and nylon 6,6 have essentially the same properties the difference is in the way these nylons are synthesized. Nylon 6 is made by ring opening polymerization of the monomer caprolactam, while nylon 6,6 is made from two monomers adipoyl chloride and hexamethylene diamine. The synthesis, properties, and applications of nylons are described in [1],... 

The possibility of a synergistic combination of properties for SPS/nylon blends has been recognized, and, therefore, the structural and physical properties [46] as well as the morphology and mechanical properties [47] of PA 6,6 (nylon 6,6)/SPS blends have been the subject of two research articles. Below is a suimnary of the mechanical properties, rheological properties, moisture response, dimensional stability, USCAR test results, and solvent resistance of SPS/nylon blends that make these blends attractive for some applications, such... 

The combination of properties for SPS/nylon blends described above has led to substantial amounts of these blends being used in under-the-hood connectors in the automotive industry. These blends have also received much interest in the carpet fiber industry. There are a great number of patents where SPS/ nylon blends are a candidate material for the application being patented. In some patents, SPS/nylon is the required material. These applications are described in more detail below. 

Blends of two immiscible polymers are created to yield a material with properties that could not be obtained otherwise. Each component of the blend overcomes the property deficiencies of the other component of the blend. In the case of syndiotactic polystyrene (SPS)/polyamide (PA nylon) blends, the blends have improved strength, ductility, and creep versus SPS formulations, and the blends have improved dimensional stability and flow versus nylon compounds. Other attributes of the SPS/nylon blends are low specific gravity (lower weight parts), high thermal diffusivity (low cycle time), excellent electrical properties, good chemical resistance, and excellent United States Council for Automotive Research (USCAR) electric wiring components test performance. In this chapter, the composition, properties, and applications for SPS/ nylon blends will be reviewed. 

It is well known that nylon-based materials absorb water and that this affects properties and results in moisture growth. In this section, the amount of moisture absorbed and resultant moisture growth for glass fiber-reinforced SPS/ nylon blends is compared with glass fiber-reinforced nylon. 

SPS/nylon blends have found wide acceptance in automotive under-the-hood connectors for aU of the technical reasons described above. In addition, the SPS/nylon blends have the required electrical insulation properties for the... 

The nonpolar nature of the chemical structure of the SPS polymer is the source of many of the most important performance attributes, including its electrical properties as well as moisture and chemical resistance, resulting in a tradeoff in which SPS s creep resistance is diminished due to the lack of the hydrogen bonding that would otherwise occur with a polar chemical structure. Blending SPS with Nylon 66 improves creep resistance significantly (Fig. 15.2), with some tradeoff in moisture resistance. 

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