Micron-sized polymer particles from tanzanian cashew nut shell liquid. Part I: Preparation, functionalization with chloroacetic acid and utilization as cation exchange resin

Micron-sized polymer particles (MSPP) were prepared by formaldehyde condensation polymerization of cashew nut shell liquid (CNSL) previously emulsified with sodium lauryl sulphate. The sizes of the MSPP were found to range from 0.1 to 4.4 mm. Increasing the emulsifier concentration had the effect of increasing the average particle size as well as the rate of polymerization. On the other hand, the polymerization rate decreased as the amount of the catalyst (sodium hydroxide) increased. The MSPP were also found to be insoluble and stable in many organic solvents and in some inorganic reagents. The average number of surface OH groups was found to be 2.29 x 1018 per milligram of polymer particles. Micron-sized carboxylated cation exchange resins (MCCER) were obtained by treating MSPP with monochloroacetic acid in an alkaline medium. The MCCER were found to exchange up to about 86 mg of calcium ion per gram of polymer at 30 ºC while the MSPP could exchange up to only about 6 mg of calcium ion per gram of polymer, at the same temperature. Compared to MSPP, the MCCER showed more than a thirteen-fold improvement in cation exchange capacity. KEY WORDS: Micron-sized polymer particles, Cashew nut shell liquid, Polymer functionalization, Cation exchange resinsBull. Chem. Soc. Ethiop. 2004, 18(1), 81-90

Adsorption of gold on activated carbons prepared from some Tanzanian carbonaceous agrow astes and bituminous coal

Bull. Chem. Soc. Ethiop. 1996, 10(1), 21-3

Preparation and characterization of activated carbons form some Tanzanian carbonaceous agrowastes

Bull. Chem. Soc. Ethiop. 1994, 8(1) 25-33

Preparation and characterization of activated carbons form some Tanzanian carbonaceous agrowastes

Bull. Chem. Soc. Ethiop. 1994, 8(1) 25-33

Preventing termite attack: environmentally friendly chemical combinations of cashew nut shell liquid, sulfited wattle tannin and copper(II) chloride

In this study, a combination of three chemicals (cashew nut shell liquid, sulfited wattle tannin and copper(ii) chloride) has been used to develop an environmentally friendly termite preservative. Cashew nut shell liquid (CNSL) is a by-product of cashew nut kernel processing factories and its use in the preservative formu- lations minimises the wastes from the factory as well as the amount of conventional hazardous preservatives from entering the environment. The formulated preservatives were tested for their ability to preserve wood blocks from a soft wood, ponderosa pine (Pinus ponderosa) and a hard wood, trembling aspen (Populus tremuloide). Sulfonated wattle tannins alone or com- bined with copper chloride at different concentrations, and cashew nut shell liquid (CNSL) without or with copper chloride were used in treating the 14 3 14 3 14 mm wooden blocks from the two wood species. The samples were exposed to termite attack in the surveyed fields in Arusha and Moshi, Tanzania. After 108 days exposure, evaluation of termite attack by measur- ing the weight losses and damage showed that the test wood treated with the combinations 40% CNSL + 1% CuCl2 and 40% CNSL + 2% CuCl2 were among the least damaged