Thermal and rheological behaviours of some random aromatic amino-ended polyethersulfone/polyetherethersulfone copolymers

• Published in: Polymer degradation and stability 2006-12, Vol.91 (12), p.3230-3236
• Main Authors: Abate, Lorenzo, Blanco, Ignazio, Cicala, Gianluca, Recca, Antonino, Restuccia, Carmelo Luca
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical reactions and properties; Copolymers; Exact sciences and technology; Gelation; Kinetics of degradation; Organic polymers; Physicochemistry of polymers; Properties and characterization; Rheological behaviour; Rheology and viscoelasticity; Thermal stability
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2006.07.012

The thermal and rheological characterizations of seven random, low molecular weight ( M n ≅ 9500 g mol −1), H 2N-ended polyethersulfone/polyetherethersulfone (PES/PEES) copolymers, at various PES/PEES ratios, were performed. The glass transition temperatures ( T g) were determined by DSC. Degradations were carried out in a thermobalance, under flowing nitrogen, in dynamic heating conditions from 35 °C to 650 °C. The initial decomposition temperatures ( T i) and the half decomposition temperatures ( T 1/2) were directly determined by TG curves, while the apparent activation energies of degradation ( E a) were obtained by the Kissinger method. In addition, the complex viscosities ( η ∗) of the molten polymers were determined in experimental conditions of linear viscoelasticity. T g, E a and η ∗ values increased linearly with PES% content, while T i and T 1/2 values showed opposite behaviour. In every case both PES and PEES homopolymers felt outside linearity. The results obtained are discussed and interpreted, and compared with those of corresponding Cl-ended copolymers previously studied.