Physical aging of poly(ether sulfone) from enthalpy relaxation measurements

✍ Scribed by Shi Ru Jong; Jun Sheng Lee; Tzyy Lung Yu

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 570 KB
• Volume: 198
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1997.021980802

✦ Synopsis

Abstract

Enthalpy relaxation due to physical aging of hydroxyl‐terminated poly(ether sulfone)s (PES) with various molecular weights was studied by DSC at three aging temperatures between T~g~ − 45°C and T~g~ − 10°C. The experimental results revealed that both the average enthalpy relaxation time 〈τ〉 and limiting enthalpy relaxation Δ__H__~∞~ decrease slightly with increasing molecular weight for PESs aged at the same temperature intervals T~g~ − T~a~ (where T~a~ < T~g~). This behavior is not quite consistent with the enthalpy relaxation process of polystyrene. Agrawal reported that the relaxation spectra for polystyrenes with different molecular weights could be superimposed when T~g~ − T~a~ was the same. The experimental results of the present work suggest that the motion of segments is affected by intermolecular hydrogen bonding through the OH groups of the PES chain ends.