Krickl, Sebastian and Touraud, Didier and Kunz, Werner (2017) Investigation of ethanolamine stabilized natural rubber latex from Taraxacum kok-saghyz and from Hevea brasiliensis using zeta-potential and dynamic light scattering measurements. INDUSTRIAL CROPS AND PRODUCTS, 103. pp. 169-174. ISSN 0926-6690, 1872-633X
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For pH adjustment and long-term preservation of natural rubber (NW) latex, the usage of ammonia or KOH is still state of the art. Unfortunately, ammonia has a bad odor, it is volatile and toxic and thus does not provide safe and comfortable handling during the processing of latex. KOH preserved latices on the other hand have a significant tendency to form potassium carbonate when getting in contact with air, which rapidly leads to a decrease of the pH value. To overcome these drawbacks, ethanolamine (ETA(2)) is suggested as a substitutional stabilizer for latex from Hevea brasiliensis (HB3) and for latex from Russian dandelion, Taraxacum kok-saghyz (TKS4), a promising crop for an alternative and renewable source of NR latex. However, little is known about the colloidal stability of ETA stabilized latices. To this purpose, zeta-potential measurements were performed to evaluate and compare the electrostatic stability of ETA, ammonia, and KOH preserved latices. In addition, dynamic light scattering was used to determine the particle size distribution of the latex dispersions. The results suggest a comparable stabilizing efficiency of the three chosen preservatives. Zeta-potentials of HB latex were in the range between -93 mV and -102 mV. For TKS latex taken directly from dandelion roots, lower absolute values were obtained (-84 mV to 93 mV) as well as for TKS latex gained by extraction (61 mV to 65 mV). However, all obtained zeta-potentials are in a range that guarantees sufficient colloidal stability. As a result, we found that ETA seems to be as suitable as ammonia or KOH for pH adjustment of TKS and HB latex, leading to comparable latex dispersion stability.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | INTEGRAL-EQUATIONS; FILM FORMATION; PHOSPHOLIPIDS; EXTRACTION; PARTICLES; PROTEINS; Hevea brasiliensis; Russian dandelion; Stability; Extraction |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry VI - Physical Chemistry (Solution Chemistry) > Prof. Dr. Werner Kunz |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 14 Dec 2018 13:15 |
| Last Modified: | 15 Feb 2019 13:56 |
| URI: | https://pred.uni-regensburg.de/id/eprint/1353 |
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