Key relationships between molecular structure and final properties are reported for standard flow and high flow grades of commercially-available polyetheretherketone (PEEK) resins that differ primarily in molecular weight and molecular weight distribution. Despite similar chemistry and composition, the molecular size-dependent structural differences associated with the PEEK resins in this study are shown to influence the crystallization rate, final crystallinity, and melt rheology during processing, which subsequently affects mechanical properties, including strength, ductility, and impact resistance. These structure-property relationships provide fundamental understanding to aid in the design and manufacturing of industrial and medical devices that leverage both the advantages common to all PEEK resins, including chemical and thermal resistance, mechanical strength, and biocompatibility, as well as more subtle differences in crystallization kinetics, melt rheology, ductility, and impact resistance. POLYM. ENG. SCI.,

Aromatic polysulfones are a family of polymers produced from the condensation polymerization of 4,4′‐dichlorodiphenylsulfone with one or more dihydric phenols. The three must commercially important polysulfones are bisphenol A based polysulfone (PSF), 4,4′‐dihydroxydiphenylsulfone‐based polyethersulfone (PES), and 4,4′‐dihydroxydiphenyl‐based polyphenylsulfone (PPSF). Polymers in this family are completely amorphous, exhibit high glass‐transition temperatures, and offer high strength and stiffness properties even at high temperatures, making them useful for demanding engineering applications. The polymers also possess good ductility and toughness and are transparent in their natural state by virtue of their fully amorphous nature. Additional key attributes include resistance to hydrolysis by hot water/steam and excellent resistance to acids and bases. The polysulfones are fully thermoplastic, allowing fabrication by most standard methods such as injection molding, extrusion, and thermoforming. They also enjoy a broad range of high temperature engineering uses. Some typical areas and industries where these polymers are used as materials of construction include hot food and beverage service, sterilizable medical components, hot water plumbing components, electrical/electronics, and a host of transportation uses in the automotive, rail, and aerospace industries.