Extensional flow behavior of aqueous guar gum derivative solutions by capillary breakup elongational rheometry (CaBER). (20th January 2016)

• Record Type: Journal Article
• Authors: Szopinski, Daniel; Handge, Ulrich A.; Kulicke, Werner-Michael; Abetz, Volker; Luinstra, Gerrit A.
• Is Part Of: Carbohydrate polymers. Volume 136(2016)
• Page Start: 834
• Page End: 840
• Publication Date: 2016-01-20
• Subjects: Extensional flow -- Capillary breakup elongational rheometry (CaBER) -- Guar gum derivatives -- Relaxation times; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2015.09.067
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Capillary breakup elongational rheometry (CaBER) of industrial relevant guar gum derivatives. Comparison of elongational and shear relaxation times shows the different influence of superstructures to the shear and elongational flow properties. Carboxymethylated guar gum derivative shows an instable filament formation in deionized water (polyelectrolyte effect). Abstract: The extensional rheological properties of aqueous ionic carboxymethyl hydroxypropyl guar gum (CMHPG) and non-ionic hydroxypropyl guar gum (HPG) solutions between the semi-dilute solution state and the concentrated network solution state were investigated by capillary breakup elongational rheometry (CaBER). Carboxymethylated guar gum derivatives show an instable filament formation in deionized water. The ratio of elongational relaxation time λ E over the shear relaxation time λ S follows a power law of λ E / λ S ∼ ( c · [ η ]) −2 . The difference of the relaxation times in shear and elongation can be related to the loss of entanglements and superstructures in elongational flows at higher strains.