Work

Thermal fractionation based on Successive Self-Nucleation and Annealing (SSA) and structural analysis of polyaryletherketone copolymers

Year: 2026

Type: article

Abstract: Polyaryletherketones (PAEKs) are high-performance semicrystalline polymers recognised for their remarkable thermal stability, chemical resistance, and mechanical strength. These properties make them suitable for applications across many sectors, including aerospace, automotive, and biomedical. Their crystallisation behaviour throughout the manufacturing process determines the performance of the final product. This work utilises the Self-Nucleation (SN) and Successive Self-Nucleation and Annealing (SSA) protocols to examine a range of polyetheretherketone (PEEK) - poly (ether diphenyl ether ketone) (PEDEK) copolymer variants, the impact of their molecular architecture, particularly comonomer ratios and branching, on the thermal behaviour and thermal domain regions of various polyaryletherketone (PAEKs) grades. The analysis revealed significant differences in self-nucleation region between the linear and branched variants, with a wider temperature spread in the linear PAEK grades including melt memory and self-seeding regions independent of the copolymer ratio. The SSA analysis allowed deconvolution of the fractionated melting peaks to provide semi-quantitative estimates of lamellar thickness distributions. A distinct bimodal thermal fractionation response was observed for the 65:35 composition, independently supported by broad asymmetric melting behaviour visible in standard DSC heating curves, and is discussed in terms of multiple plausible structural origins. A higher PEDEK content promotes the development of thinner lamellae in a greater proportion. These findings highlight the capability of SN and SSA to resolve crystalline heterogeneity in PEEK-PEDEK copolymers and to explain the effects of comonomer composition and molecular architecture on lamellar population distributions beyond the resolution of conventional DSC.

Source: Polymer Testing

DOI: 10.1016/j.polymertesting.2026.109337

Authors: Monis L. Mohammed, Nan Yi, Melany McBean, Ken E. Evans, Adam Chaplin, Oana Ghita

Institutions: University of Exeter, Victrex (United Kingdom)

Language: English

Topic: Polymer crystallization and properties

Subfield: Polymers and Plastics

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,370

Funder: University of Exeter