The fruits of some wild plants were examined for their contents of mineral elements and ascorbic acid. High levels of ascorbic acid were found in fruits of Sclerocarya birrea (403.3 mg/100 g) and Adansonia digitata (337 mg/100 g). In nine of the fruits examined, the mineral contents (Ca, P) were comparable with average values found in common fruits. The iron contents were however 2-5 times higher than the values for common fruits.

Alcoholysis-polyesterification method was used in the investigation of utilization of Ximenia americana seed oil in the formulation of alkyd resins. The extracted oilseed gave an oil yield of 45.7% (w/w) and the physicochemical characterization indicated it is semi-drying in nature with iodine value of 152.3 g I 2 100 g -1. The fatty acid analysis of the oil carried out earlier revealed oleic and linolenic as dominant fatty acids, having values of 72.1 and 10.3% respectively. Four grades of alkyds were formulated at 40% (I), 50% (II), 60% (III) and 70% (IV) oil lengths. The reaction progression was followed by determining the acid value of the aliquots for the reaction mixture at various time intervals beside the volume of water evolved. Kinetic studies showed that the reaction was second-order with values of 3.12 x 10 -4 , 2.44 x 10 -4 , 2. The 40 and 50% oil length alkyd films were resistant to acid, brine and water with little resistance to alkali. Characterization of paint based on two alkyd resin derivatives, 40 and 50% oil lengths, gave values for surface drying and tack-free property of less than 2 and 5 hours respectively in respect of the 40% oil length.

SYNOPSISPreliminary investigations have been conducted on the graft copolymerization of methylmethacrylate onto Caesarweed fiber, initiated by potassium permanganate and the toluene redox system. The percentage graft yield increased with permanganate up to 132% in the concentration range, 1.0 X lo-* to 5.0 X lo-' M at 4OoC. The effects of varying concentrations of toluene, acids, and monomer on graft yield were also investigated. Graft yield increased initially and then decreased on varying the concentrations of toluene from 2 X lo-' to 20 X lo-* M. The graft yield increased with temperature between 20 and 5OOC.At 60°C, the graft yield decreased considerably by up to 60% of the value at 50°C. The calculated activation energies for the overall reaction, and for the initiation process, are 9.15 and 9.30 Kcal mol-' , respectively. 0 1993 John Wiley & Sons, Inc. I NTRO DUCT10 NGrafting of synthetic polymers onto cellulosic and protein fibers has received considerable attention because, in some cases, grafting yields copolymers with improved physicochemical properties with industrial and commercial value. Specifically, grafting of acrylonitrile onto jute fibers13 resulted in the fibers' improved extensibility and light fastness. Similarly, grafting of methylmethacrylate onto jute fibers l4 yielded a copolymer with an enhanced thermal property. However, for cellulosic fibers, different morphological features of the polymer matrices are known to account for varying grafting characterist i c~. '~,~~ Caesarweed, Urenu lobatu I, is of the mallow family, Malvacea, which is one of the most important of all fiber plant families. The plant is cultivated in warm regions of several countries, including West Africa, and it often grows wild in abundance. The bast fibers are cellulosic materials, closely resembling jute, but somewhat shorter and coarser. The * To whom correspondence should be addressed. fibers are used as substitutes for jute and find local application in the production of twines and sacks. Information about the chemical composition and morphological properties of the fibers is sparse; neither is there any report on the grafting of synthetic polymer onto the fibers. This article presents the results of a preliminary study of the graft copolymerization of methylmethacrylate ( MMA) onto Caesarweed fibers, initiated by acidified potassium permanganate and the toluene redox system. EXPERIMENTALToluene (BDH) was treated with sulfuric acid and was washed copiously with distilled water to neutral pH. It was dried over anhydrous calcium chloride and was fractionally distilled before use.Methylmethacrylate ( Aldrich Corp.) was washed with 5% aqueous sodium hydroxide and sodium chloride solutions, was dried over anhydrous calcium chloride, and was then fractionally distilled. The middle fraction of the monomer was collected and was stored under refrigerated conditions. All other reagents, that is, potassium permanganate, glacial acetic acid, and sulfuric acid (-18 645

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The Seeds of the fruits of some wild plants were analysed to establish their proximate compositions and the physico-chemical characteristics of the oils. The iodine values of the oils were not greater than 88 but the saponification values were in the range 157-261 mg KOH. Proximate values of the protein, oil and carbohydrate contents of the seeds suggest that they may be adequate for the formulation of animal feeds, subject to a knowledge of the levels of possible toxic substances. The Storage property of the oil from Lophira lanceolata seed were studied over a period of four weeks under conditions of light (ambient), darkness (ambient) and refrigeration. The iodine value of the oil decreased in all cases but much more so on exposure to light. In contrast, the peroxide value of the oil showed very little change under conditions of darkness and refrigeration over the same period but increased by seven fold for the photo-exposed oil.