PPO/PA blends

PPO/PA blend for passenger cars. A new conductive version of the on-line paintable Triax PA/ABS blend is proposed by Bayer. Heat deflection temperature is in the 180-200°C range ensuring resistance to the temperatures encountered in the drying ovens during cathodic dip coating. 

The PPO-PA blends, which are sold by General Electric under the trade name Noryl GTX, can be baked and painted at 190°C without noticeable warpage or distortion, and have been used for producing automobile fenders. 

The PPO-PA blends shown a mold shrinkage of 0.001 in./in. The molding pressure in 15 X10 Ibf/in. (103 MPa) and the processing temperature 260°C. The heat-deflection temperature of the molded specimen under flexural load of264 Ibf/in. is typically 190°C and the maximum resistance to continuous heat is 175°C. The coefficient of linear expansion is 10 cm/cm °C. The mechanical properties of the PPO-PA blends are shown in Table 4.29. 

Dimensional stability PC/ABS blends for cowl panels PPO/PA blends for wing panels... 

Noryl GTX PPO /PA blends get their unique properties thanks to the true incompatibility of PPO and polyamide. In this case morphology, rheology and properties are mainly controlled through compatibilizatiou and impact modification technology. 

While the water absorbtion of PPO -PA blend is a straight function of the polyamide content (fig.10), the net effect on the mechanical properties shows major synergism as Indicated in the tensile stress-strain diagram (fig. 11) where the dry as molded and 50 % relative humidity conditioned PP0 /PA blends maintains very close properties. A major drop In tensile strength is observed for Its parent polyamide 66. 

T0U6HNESS OF LARGE BODY PARTS AFTER PAINT OPERATION FIG 12. Modified PC/PBT Blends and PPO /PA Blends as Exterior Automotive Thermoplastic Materials. 

Finally, Noryl PPO/PA blends are challenging PC/PBT in bumper fascia applications for mid to top... 

Constant product development has been a feature in the development of the PPO/PPE product family. Higher conductivity, mineral-filled and low odour emission grades are some examples of how the product has been improved to open up new market opportunities. GE Plastics also introduced an improved, conductive version of Noryl GTX (PPO/PA blend), which dispensed with the need to prime plastic parts before painting them. By adding conductive material, it was possible to develop a thermoplastic that makes it easier to paint hard-to-reach places. 

Engineering polymer blends (EPB) can be roughly divided into blends of an engineering plastic or resin (ER) with a commodity plastic, blends of an engineering plastic with another engineering plastic, blends of an engineering plastic with an elastomer and, blends which contain three or more polymers. We can therefore get combinations such as PPO/PS PPO/PA PC/ABS PET/PBT PBT/PC/SAN etc. each of the blends may in turn be filled. When blends are made the objective is to simultaneously optimize blend formulations, in respect of several properties important for a particular application, sacrificing those which are not important. 

Addition of nanoparticles results in less coalescence of particles during the melt processing, causing improved compatibilization. For example, exfoliated clay compatibilization, snch as in a polycarbonate/polymethylmethacrylate (PC/ PMMA) system, polyphenylene oxide/polyamide (PPO/PA), polyamide/ethyl-ene propylene diene elastomer (PA/EPDM) rnbber, polystyrene/polymethyl-methacrylate (PS/PMMA), and polyvinyl fluoride/polyamide-6 (PVF/PA) blends, is affected by lowering the interfacial tension between the two phases that are phase separated. 

Polymer alloys are commercial polymer blends with improvanent in property balance with the use of compatibilizers. Texas A M University [1] has patented a com-patibilizer that can result in a product with high impact resistance as well as scratch resistance. The blend is composed of HIPS or polypropylene (PP) and a compati-bilizer made of a triblock copolymer of styrene-ethylene-propylene. Udipi [2] discovered that polymer blends composed of PC, a copolyester of PETG, and nitrile rubber exhibit a superior balance of properties. Reactive compatibilization of PC/ SAN blends at various AN compositions were conducted by Wildes et al. [3] using a SAN-amine compatibilizer. PC and SAN were found to be miscible over a range of AN composition by Mendelson [5]. Nylon/ABS blends can be compatibilized by use of SAN-maleic acid (Lavengood et al. [6]). Styrene-GMA copolymers can be used as compatibilizers for PS/PA, PS/PBT, PS/PET, and PPO/PBT blends. 

End-functional polymers can also be prepared by modification of existing polymers. For example, PPO was successfully end-capped by epoxide (PPO-E) and anhydride (PPO-A), respectively [36, 37]. Because of the reactivity of the epoxide with the carboxylic acid end groups of PBT, PPO-E was used as a reactive compatibilizer for PPO/PBT blends. Similarly, during melt blending with PA 6,6, the anhydride end-groups of PPO-A were found to react with the amine end-groups of polyamide. As a rule, PPO-b-PBT and PPO-b-PA 6,6 copolymers were formed at the interface their blocks were interconnected by an ester and an imide bond, respectively. 

Electrical components (switches and timers) Require good mechanical properties (to prevent breakage during assembly), electrical properties, heat performance, tracking resistance and flame retardancy. PA, PBT and PPO/PPE blends provide good electrical, chemical and... 

Polyamides are the dominant polymers used for mirror housings, with 3,400 metric tons consumed in vehicle exteriors manufactured in North America in 2000. Polyphenylene oxide/polyamide filled with carbon fibers was recently introduced to provide charge dissipation during the electrostatic painting process of mirror housings. As with PPO/PA body panels, this semiconductive polymer blend ensures high paint-transfer efficiency while eliminating the need to apply a separate conductive primer (Fig. 15). 

The chemical pretreatment methods mentioned are mostly used for TPOs, but in some cases can also be effective when used on polyamide (PA), polybutylene terephthalate (PBT), or other crystalline polymers, as well as some blends like poly(phenylene oxide)/polyamide (PPO/PA), are flamed. As a possible future trend, research is currently underway (plasma polymerization) attempting to combine a pretreatment for adhesion and to provide the surface conductivity on necessary on plastic parts for acceptable electrostatic application (15). 

Engineering polymers are often used as a replacement for wood and metals. Examples include polyamides (PA), often called nylons, polyesters (saturated and unsaturated), aromatic polycarbonates (PCs), polyoxymethylenes (POMs), polyacrylates, polyphenylene oxide (PPO), styrene copolymers, e.g., styrene/ acrylonitrile (SAN) and acrylonitrile/butadiene/styrene (ABS). Many of these polymers are produced as copolymers or used as blends and are each manufactured worldwide on the 1 million tonne scale. 

Modification of Engineering Resins Specific interaction of the phosphonium ionomer from Exxpro elastomer with selected engineering resins such as Polycarbonates(PC), Polyesters(PET), Polyacrylates(PAE), Polyamides(PA), Polyphenylene Oxide(PPO), and Acetals(PAc) can be utilized to compatibilize, impact modify or nucleate the above resin in blends with similar polymers. Typical examples are ... 

Blends of PPO and polyamide (PA, nylon) are incompatible but good properties can be obtained through the use of compatibilizing agents. The PPO is dispersed in a continuous nylon matrix in these blends. Because of the incompatibility of the two phases, the modulus decreases very little at the Tg of PA (71°C) and is maintained up to the Tg of the PPO phase (208°C). 

The reactive methods of compatibili2ation developed subsequently allowed the second generation Noryl (a blend of PPO with PA) to be developed. The compositions claimed usually cover 30-70% of each of the main ingredients, PPO and PA, with additionally up to four parts of such modifier as polycarboxylic acid, trimellitic anhydride acid chloride, quinine, oxidized polyolefin wax, and so on. In most cases, PA forms a matrix with spherical inclusions of PPO acting as compatibilized low-density filler. 

Highly recommended for these polymers PVC, PV c, PS, PMMA, PP, PF, PA, PE, acrylics, nitrocellulose, cellulosic resins, EP, EC, NBR, SBR, natural rubber, PU, phenolic resins, CA, NC, ABS/ PC, PPO blends (wifli HIPS and other polymers). ... 

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