Characterization of Polyetheretherketone and Other Engineering Thermoplastics,
Abstract
Three engineering thermoplastic materials were characterized by thermal/spectroscopic means to assess their suitability in fiberglass-filled molding resins for Mound applications. The three resins examined were: polyetheretherketone (PEEK) from ICI, Ltd., polyetherimide (PEI) from General Electric, and polyethersulfone (PES) from ICI. Thermogravimetric analysis of the three thermoplastics in N2 showed that all had a decomposition onset temperature > or = 525 deg C with PEEK >PEI >PES. Melt thermal stability analyses of glass-filled PEEK and of PEI showed <1% weight loss after 2 hr (N2). Thermomechanical analysis (TMA) of glass-filled PEEK revealed a low temperature (approx. 60-70 deg C) transition below Tg (approx. 150 deg C). This transition disappeared on subsequent TMA runs and did not reappear on aging at room temperature, which suggests it was the result of molding stresses. "Extra" transitions below Tg were also noted for PES and PEI. Direct probe/mass spectroscopy reconstructed ion chromatograms showed water and phenyl sulfone ions to be present in both PES and PEEK (and volatilized below 200 deg C in vacuum). Water only was observed in PEI. The presence of phenyl sulfone in PEEK was confirmed by FT-IR, and sulfur was found in amounts up to 0.23% by weight in 30% glass-filled molding compounds. A polymerization solvent, such as diphenyl sulfone, is a probable source. Fluoride (from a monomer used in the PEEK polymerization) was also detected in amounts up to 0.17% by weight in the 30% fiberglass molding compounds. jg p6
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 13, 1984
- Accession Number
- ADA305275
Entities
People
- Allan B. Nease
- Richard O. Yelton
- Ruth B. Whitaker