A series of sulphonated polyurethane ionomers based on poly(tetramethylene oxide) of molecular weight 1000, neutralized with Ca2+, Ni2+, Zn2+, Cd2+, Cs+ and Eu3+ were examined by extended X-ray absorption fine structure (EXAFS) spectroscopy. The degree of local order shown by EXAFS correlates inversely with the strain at which stress crystallization begins, indicating that the cohesiveness of the ionic aggregates controls the large-strain behaviour of the materials by suppressing ion-hopping. Upon hydration, the materials lose their mechanical strength. The local structure in the Ca2+-neutralized material is insensitive to hydration, while that in the Ni2+-neutralized material changes dramatically.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics