Preparation and characterization of polymeric materials from Tanzanian cashewnut shell liquid.

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Date
2001
Journal Title
Journal ISSN
Volume Title
Publisher
University of Dar es Salaam
Abstract
Polymeric materials are now becoming inseparable from human beings. These materials are increasingly being made for use in various industrial and domestic activities. In this study Micron-Sized Polymeric Particles (MSPP) were prepared by a condensation reaction between Cashew Nut Shell Liquid (CNSL) and formaldehyde in an aqueous medium at 60°C through an emulsion polycondensation method. Sodium Lauryl Sulfate (NaLS) was used as a stabilizer and an emulsifier. Polymerization rate and yield were both found to increase as pH of the reaction mixture increases or as emulsifier concentration increases. The MSPP were found to have sizes ranging from 0.1 to 4.4 um. The sizes were found to decrease as the emulsifier concentration increase or increase as NaOH concentration increase. The latter reduced the effective concentration of the emulsifier. These particles appeared to be physically stable in alkalis, mineral acids and organic solvents. The surfaces of MSPP were chemically modified by reaction with monochloroacetic acid to produce an Ion Exchange Resin (IER). Cation Exchange Capacity (CEC) of IER was found to vary from 3.8 to 5.4 meq/g depending on both the method used to determine CEC and the size of the particles. Cation exchange of both modified (IER) and unmodified MSPP were investigated and the former was found to exchange up to 86.36 mg of calcium ion per gram of the polymer, whereas the latter could exchange up to about 6.57 mg of calcium ion per gram of the polymer at 30°C. On the other hand the pKa of the IER prepared was found to be 6.2. Generally, these results showed that the IER prepared are useful and suitable for ion exchange applications.
Description
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF QD281.P6I58)
Keywords
Cashnut shell liquid, Polymerization, Tanzania
Citation
lomo, O. O. (2001). Preparation and characterization of polymeric materials from Tanzanian cashewnut shell liquid. Master dissertation, University of Dar es Salaam.