Thermoplastics polyethersulfone

In the past few years, a whole range of resins and fiber-reinforced composites have been developed based on new, tough high-temperature thermoplastics. Polyethersulfone (PES) is one such polymer which is generating a great deal of interest, especially as a structural material occupying a unique place in the industry [1-9]. 

A number of amorphous thermoplastics are presently employed as matrices in long fiber composites, including polyethersulfone (PES), polysulfone (PSU), and polyetherimide (PEI). AH offer superior resistance to impact loading and higher interlaminar fracture toughnesses than do most epoxies. However, the amorphous nature of such polymers results in a lower solvent resistance, clearly a limitation if composites based on such polymers are to be used in aggressive environments. 

Newer resins include polysulfone, polyethersulfone, polyetherimide, and polyetherketone. Some of these newer materials are high temperature thermoplastic, not thermoset, resins. They are being promoted for the design of injection-molded printed circuit boards in three-dimensional shapes for functional appHcations as an alternative to standard flat printed circuit boards. Only semiadditive or fully additive processing can be used with these devices. 

Amorphous Thermoplastics. Polysulfone, polyethersulfone, and polyarylsulfone are examples of amorphous thermoplastics. These materials have high Ts and can stand temperatures up to 200°C for a long period of time. Amoco and ICI are principal suppHers of this class of material. 

The primary resin of interest is epoxy. Carbon-fiber-epoxy composites represent about 90% of CFRP production. The attractions of epoxy resins are that they polymerize without the generation of condensation products that can cause porosity, they exhibit little volumetric shrinkage during cure which reduces internal stresses, and they are resistant to most chemical environments. Other matrix resins of interest for carbon fibers include the thermosetting phenolics, polyimides, and polybismaleimides, as well as high-temperature thermoplastics such as polyether ether ketone (PEEK), polyethersulfone (PES), and polyphenylene sulfide. 

Among these methods, incorporation of thermoplastics has been highlighted as a new approach to enhance the toughness of thermosets without significantly lowering the desirable properties. Rigid thermoplastics with high Tg, such as polyethersulfone [11-16], polyether-imide [17-19], and polysulfone [20-23], were frequently used in this approach. 

Adhesion studies of epoxy resins modified with high modulus and high glass transition temperature thermoplastics have shown adhesion can reach or even exceed that of the unmodified resin. The use of flexible polyamides or flexible epoxides resulted in shear strength increases in epoxy systems employed by Cunliffe et al. [144],polyethersulfones [18,145],polyetherimides [109,146,147], and polyetherketones [148-150]. 

Polyphthalate carbonate Polyethersulfone Poly-4-methylpentene-l Good thermal properties, autoclavable Excellent thermal stability, resists creep UV/moisture sensitive, high crystalline melting point, lowest density o all thermoplastics... 

Polyarylsulfones are a class of high-use temperature thermoplastics that characteristically exhibit excellent thermal-oxidative resistance, good solvent resistance, hydrolytic stability, and creep resistance (10). In 1965, Union Carbide announced a thermoplastic polysulfone based on dichlorodiphenylsulfone and bisphenol A (11). This polysulfone became commercially available in 1966 and was designated as Udel polysulfone. Since 1966, Imperial Chemical Industry (ICI), Minnesota Mining and Manufacturing (3-M), and Union Carbide have commercialized polyarylsulfones that contain only aromatic moieties in the polymer structure. These materials have been designated Vlctrex polyethersulfone (ICI), Astrel 360 (3-M), and Radel polyphenylsulfone (Union Carbide). 

The two commercially significant polysulfones are (a) the polysulfone derived from bisphenol A, which is simply referred to as polysulfone (PSO Udel , Amoco) and (b) the polyethersulfone (PES Victrex , ICI). The current world-wide consumption of all polysulfones is estimated to be less than 19 kton/y about 70% of which belong to the polysulfone (PSO). The hydrolytic stability of polysulfones appears to be their unique advantage over other high heat, transparent thermoplastics... 

Polyethersulfone Thermoplastic aromatic polymer has good heat and fire resistance, transparency, dielectric properties, dimensional stability, rigidity, and toughness, but poor solvent and stress cracking resistance, processibility, and weatherability. Processed by injection, blow, and compression molding and extrusion. Used in high temperature applications, electrical devices, medical devices, housings, and aircraft and auto parts. Also called PES. 

High performance thermoplastics PEEK polyetherimides certain polyimides polyamide-imide polysulfone polyethersulfone... 

Thermoplastics are sometimes added to epoxy resins. Thermoplastic-modified epoxy resins [43,44] based on tri- and difunctional epoxy resins cured with DDS and blended with polyethersulfone form the basis for the matrix material in a composite used for the Boeing 777 aircraft. The incorporation of the thermoplastic helps the processing characteristics and also improves the mechanical properties, notably the toughness. The thermoplastic is able to phase separate from the epoxy phase and acts as a reinforcement for the epoxy matrix, enhancing its high temperature properties. The maximum use temperatures of all these resins will typically be 30 to 50 degrees lower than the cited Eg, assuming the same cure schedule. 

Mac MacKinnon, A. J., Jenkins, S. D., McGrail, P. T., Pethrick, R. A. Cure and physical properties of thermoplastic modified epoxy resins based on polyethersulfone. J. Appl. Polym. Sci. 58... 

PLCs have been shown to nucleate systems which are hard to crystallize by any other means. Polyethersulfone (PES) is a high temperature thermoplastic which, even when cast from solution, is unable to crystallize [84], as opposed to, for example, PC. However, when solution blended with 30 wt% wholly aromatic longitudinal PLC (structure not reported), spherulites of the PES can be formed and it is suggested that the combined effect of solvent molecules to lubricate the motion of the crystallizing PES molecules and a nucleant (PLC) is required, either condition on its own not being sufficient. Similar attempts to crystallize the blend from the melt failed. 

PES Polyethersulfone PEST Thermoplastic polyester PET Polyethylene terephthalate PETG Polyethyleneterephthalateglycol... 

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