Nylon blend properties

In a partially crystalline homopolymer, nylon 6, property enhancement has been achieved by blending with a poly(ethylene-co-acrylic acid) or its salt form ionomer [24]. Both additives proved to be effective impact modifiers for nylon 6. For the blends of the acid copolymer with nylon 6, maximum impact performance was obtained by addition of about 10 wt% of the modifier and the impact strength was further enhanced by increasing the acrylic acid content from 3.5 to 6%. However, blends prepared using the salt form ionomer (Sur-lyn 9950-Zn salt) instead of the acid, led to the highest impact strength, with the least reduction in tensile... 

Cellulose triesters, moisture properties of selected, 5 416t Cellulose trinitrate, 5 396 Cellulose valerate(s), 5 419 moisture properties, 5 416t Cellulose x, 5 373, 378-379 8 21 Cellulose xanthate, 4 716 5 383 20 559 Cellulosic-acrylic fibers, dyeing, 9 201-202 Cellulosic fiber blends, dyeing, 9 199-202 Cellulosic fiber—nylon blends, dyeing, 9 202 Cellulosic fibers, 18 96... 

Polyester Fiber-Nylon Blends. This fiber blend is used in apparel fabrics as well as in earpels. Disperse dyes dye both fibers, however they possess only marginal fastness properties on nylon. Therefore it is important to select those disperse dyes that dye nylon least under the given circumstances. The nylon is dyed with acid dyes, selected according to the fastness requirements. 

Insect resist finishes are most commonly applied during dyeing. The best light fastness and wet fasmess properties are obtained when the finish is able to fully penetrate the fibres. When applying insect resist finishes to wool/nylon blends, care must be taken in the choice of the particular finish used. Chlorphenylid derivatives exhaust preferentially to nylon, leaving the wool fibres unprotected, whereas permethrin-based products distribute themselves more uniformly between the two fibre types. 

Blending of polymers provides a simple and inexpensive method of nylon modification. The mechanical and thermal properties of nylons may be improved by blending with other polymers. However, it is not easy to obtain synergism in the meehanical properties of the blend components. Usually, incompatibility causes the mechanical properties of a nylon blend to fall far below the values predicted by the additivity rule for mixtures. 

Papazoglou and Rosenthal[71] produced nylon blends having improved low-temperature properties. Moldable nylon-6 blends with improved low-temperature impact strength and reduced brittleness were prepared by melt blending nylon-6, maleic anhydride-g-ethylene-propylene-diene terpolymer, and rubber modified styrene-maleic anhydride copolymer. The impact property of the rubber-modified nylon composition is given in Table 5. The blend components were melt blended at temperatures between 260 and 310 °C. As a standard, all three components of the blend were simultaneously melt blended (A). Nylon-6 was melted first and then the functionalized terpolymer was melt blended prior to downstream introduction of the rubber modified copolymer (B). Nylon-6 and the functionalized terpolymer were first melt blended and then the rubber modified copolymer was added to the melted mixture at a downstream feed port (C). 

Table 4. Effect of blend composition on the impact property of the nylon blends...

Nylon-6 and the functionalized terpolymer were first melt blended in a twin- screw extruder and then the extruded preblend was melt blended with the rubber modified copolymer using another twin- screw extruder (D). As shown in Table 5, the impact property of the nylon blend was affected by blending procedure as well as blend... 

Important nylon blends commercially available and their advantageous properties are given in Table 9. 

Table 9. Commercially available nylon blends and properties improved...

Abacha, N. and Fellahi, S. 2005. Synthesis of polypropylene-gr( -maleic anhydride com-patibilizer and evaluation of nylon 6/polypropylene blend properties. Polymer International 54 909-916. 

Polyamides such as PA6 are engineering thermoplastics with high heat and solvent resistance properties and hence make ideal thermoplastic matrix candidates of choice to make high-performance TPVs with dynamically vulcanized mbber blends. Although nylon blends with low rubber content have been known for a long time as impact-modified nylons, as discussed under Sect. 19.7.1, elastomeric TPV blends of polyamide with high rubber content (>60 %) have not been commercially available until recently. Because of their higher thermal and chemical resistance performance, the polyamide-based TPVs have often been called super-TPVs (Leaversuch 2004). 

Current micro-mechanical understanding of functional elastomer-nylon blends presumes a continuum behaviour of the nylon matrix and rubber particle inclusions, i.e. that the properties of the matrix are unaffected by the inclusion of rubber toughening particles and that the rubber particles do not contain subinclusions (2-7). Results... 

Organophilic clays have also been blended with PLA. Ogata et al. [133] modified MMT with distearyldimethylam-monium chloride and that was solvent-cast blended with PLLA (Af = 2 x 10 ) using chloroform. Results showed that the tactoids (several stacked sificate monolayers) lay almost parallel to the film surface and were stacked with insertion of PLLA lamellae in the thickness direction of the film. Such preferred orientation of the tactoids is assumed to give excellent water barrier properties to the blends, as reported for nylon 6-clay hybrids (NCH) by Kojima et al. [134] In this nylon blend, the absence of clay delamination gave relatively poor tensile improvements compared to true nanocomposites. 

Exterior door handles are another application that has turned to plastics to balance chemical resistance and mechanical properties. Many filled thermoplastics such as blends of PC and polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and nylon have been tried or used in this application, with nylon as the clear wirmer. Exterior mirror housings likewise use many thermoplastic solutions such as ABS, PC/ABS, blends of polyphenylene oxide (PPO) and polystyrene (PS), nylon, blends of PP and ethylene propylene diene monomer (EPDM), and weatherable ABS. Again, nylon clearly dominates this application in terms of volume. Many other exterior parts continue to adopt thermoplastic solutions. Figure 14 shows an impingement shield constructed from LGF PP. 

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. 

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... 

Figure 16.2 Dry-as-molded (DAM) versus moisture-conditioned room temperature tensile properties for 30% glass fiber-reinforced SPS/nylon blends and 30% glass fiber-reinforced PBT. (Moisture-conditioned samples were conditioned at 40°C and 50% r.h. for 1 week.).

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. 

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. 

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... 

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