The rheological properties of weak gels of poly(vinyl alcohol) and sodium borate

✍ Scribed by I.D. Robb; J.B.A.F. Smeulders

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 426 KB
• Volume: 38
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/s0032-3861(96)00755-0

✦ Synopsis

The aim of this work was to establish whether the lifetime of the junction zones in the poly(vinyl alcohol)/ borate gels depended on the chemical composition or concentration of the constituents. It was found that the maximum in the distribution of lifetimes was about 0.3 s and independent of the polymer, borate concentrations and of the degree of hydrolysis of the polymer. The gels changed their non-linear rheological behaviour with age, being strain softening when freshly prepared but strain hardening after a few days. This change in behaviour was attributed to a redistribution of borate ions with time.