Thermoplastics polyether sulfones

The two aluminum alkoxide primers on mild steel showed improved adhesion and better resistance to crack propagation with both the thermoplastic polyether-sulfone (PES) and the FM 300U thermoset epoxy adhesive. The titanium alkoxide exhibited the poorest resistance to crack growth, while tetrabutyl orthosilicate showed intermediate behavior between the two aluminum alkoxides and the titanium alkoxide. 

The study considered here employed materials obtained from McDonnell Aircraft Co., through Dexter Hysol, under the Air Force program Development of Ultra Lightweight Materials . They contained the Courtaulds Research Apollo 45-850, consisting of 5 pm diameter carbon fibers in Dexter Hysol s HC 9106-3 di-, tri- and tetrafunctional epoxy resin, toughened by addition of the thermoplastic polyether sulfone (PES). The thermoplastic PEIS toughening agent, present in this epoxy matrix, is presumed to phase separate out once it has cured. These panels were fabricated in an autoclave by Dexter Hysol. 

Polyether sulfones (PES) are another class of engineering thermoplastics generally used for objects that require continuous use of temperatures around 200°C. They can also be used at low temperatures with no change in their physical properties. 

In general, properties of polyether sulfones are similar to those of polycarbonates, but they can be used at higher temperatures. Figure 12-6 shows the maximum use temperature for several thermoplastics. Aromatic polyether sulfones can be extruded into thin films and foil and injection molded into various objects that need high-temperature stability. 

Thermoplastics for aircraft interiors have been evaluated by this technique (10b) in accordance with the FAA specification (peak rate of heat release of 65 kilowatts per meter squared (Kw/m 2) or less). In these tests (10b) Polyether sulfone demonstrated marginal compliance. For Polyether imide (PHI) and PEI/Polydimethyl siloxane copolymers peak heat-release rates were well below the specified value. The overall trend suggested a possible correlation of peak heat release values with aromatic carbon content in the polymers evaluated. 

PC PE PES PET PF PFA PI PMMA PP PPO PS PSO PTFE PTMT PU PVA PVAC PVC PVDC PVDF PVF TFE SAN SI TP TPX UF UHMWPE UPVC Polycarbonate Polyethylene Polyether sulfone Polyethylene terephthalate Phenol-formaldehyde Polyfluoro alkoxy Polyimide Polymethyl methacrylate Polypropylene Polyphenylene oxide Polystyrene Polysulfone Polytetrafluoroethylene Polytetramethylene terephthalate (thermoplastic polyester) Polyurethane Polyvinyl alcohol Polyvinyl acetate Polyvinyl chloride Polyvinyl idene chloride Polyvinylidene fluoride Polyvinyl fluoride Polytelrafluoroethylene Styrene-acrylonitrile Silicone Thermoplastic Elastomers Polymethylpentene Urea formaldehyde Ultrahigh-molecular-weight polyethylene Unplasticized polyvinyl chloride... 

Because the components must initially form miscible solutions or swollen networks a degree of affinity between the reacting components is needed. Therefore, most of the investigations into epoxy IPNs have involved the use of partially miscible components such as thermoplastic urethanes (TPU) with polystyrenes [57], acrylates [58-61] or esters which form loose hydrogen-bound mixtures during fabrication [62-71 ]. Epoxy has also been modified with polyetherketones [72],polyether sulfones [5] and even polyetherimides [66] to help improve fracture behavior. These systems, due to immiscibility, tend to be polymer blends with distinct macromolecular phase morphologies and not molecularly mixed compounds. 

Various kinds of engineering thermoplastics such as polyether sulfone, polyether imide, polyaryl ether ketone, and polyphenylene oxide have been studied as toughening agents for... 

An alternative approach to using a rubber such as CTBN as the disperse phase is to use an engineering thermoplastic such as polyether sulfone or a polyimide in which the mechanical properties and Tg are more closely matched to those of the resin. These systems exhibit LCST behaviour, so the cure tempemture is located below the initial miscibility gap... 

More recently, thermoplastics such as polyphenylene sulfide (PPS), polyether sulfone, and polyether ether ketone (PEEK) have entered the primary structures market in competition with thermosets. 

The term HT-thermoplastics is used for polymers, which in the absence of fillers, have a continuous-use temperature above approx. 200 °C. In contrast, standard plastics, such as PVC, polyethylene or polystyrene, have continuous-use temperatures of the order of 100 °C. In addition to their high temperature stability, HT-thermoplastics, in general, possess good resistance to chemicals and usually also low flammability. Among the most important HT-thermoplastics are polyphenylene sulfides (PPS), polysul-fones (PSU), polyether sulfones (PES), polyether imides (PEI), polyetherether ketones (PEEK) and polyarylates (PAR). 

Polyether sulfone is a high-temperature engineering thermoplastic with the combined characteristics of high thermal stability and mechanical strength. It is a linear polymer with the following structure ... 

Polyether sulfone, polycarbonate (glass), nylon (glass), polypropylene (glass), thermoplastic polyester, polyetherimide, vinyl ester, polyetheretherketone, epoxy, pol5dmide... 

Polyethylene, silicone, PVC, thermoplastic elastomer, polyurethane, ethylene vinyl acetate Epoxy, nylon (glass or carbon fiber), polyurethane, thermoplastic polyester (glass), polyphthalamide, polyetheretherketone, polycarbonate (carbon fiber), polyetherimide, polyether-sulfone Nylon (glass or carbon fiber), polyurethane, thermoplastic polyester (glass), polyetheretherketone, polyetherimide, polyphthalamide, polyphenylene sulfide (glass or carbon fiber)... 

Polypropylene is generally used as oriented polypropylene. Polyvinyl chloride film is commonly used in plasticized form. Polyvinylidene chloride is often known as Saran and is generally used in copolymer form with acrylonitrile. Polyethylene terephthalate is a thermoplastic polyester. Polystyrene is sometimes used in biaxially oriented form. Polycarbonates, polysulfones, polyether sulfones, poly-imides, polyetherimides, and several fluoropolymers are also used for specialty applications. 

Fig. 19.1 The plastics pyramid according to thermal literature data of common polymers preferred materials for HT-PEM applications are in the upper right region TPI thermoplastic polyimide, PES polyether sulfone, P P)SU poly(phenylene)sulfone, PE E)K polyether(ether) ketone, LCP liquid crystal polymer, e.g., Vectra, PPS polyphenylene sulfide, PTEE polytetrafluoroethylene.

High performance engineering thermoplastics have recently assumed increasing importance due to their exceptional properties at elevated temperatures. A number of such specialty polymers have been introduced into the market for high temperature applications and examples of some of the outstanding ones are polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polyether sulfone (PES), polyaryl sulfone (PAS), polyether ketone (PEEK), polyether imide (PEI) and polyarylate (PAr). 

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