In our continuous effort to develop a paint binder from amino resins, amino resins from different aldehydic groups were synthesized to produce urea, formaldehyde (UF), urea acetaldehyde (UA), urea proparaldehyde (UP) and urea butaldehyde (UB) at different degree of substitution (Mono -tetra). Some physical properties of these resins were evaluated. The viscosity, gel time, density and refractive index of the resins (except UB) were found to increase with increase in alkyl length of the aldehydic group while turbidity (except UF) increased with increase in alkyl length of the aldehydic group. On the other hand, melting point and moisture uptake decreases with increase in alkyl length of the aldehydic group. In the case of the degree of substitution the viscosity, turbidity, melting point and moisture uptake increases with increase in the degree of substitution while the gel time and refractive index were found to decrease with increase in the degree of substitution. However, an initial rise followed by a gradual fall was recorded for density for the different degree of substitution for all the resins. Samples for UF and UA with the exception of monoethylol urea were too hard brittle and has low water resistance while those of UP and UB resins were too soft and remained as semi solid in the cured state at room temperature (30 o C). This result indicates that these resins cannot be used alone as paint binder. However, monoethylol urea seems to have sieved itself out as a compromise candidate who is neither brittle nor too soft. A comparison of monoethylol urea with some physical properties of some convectional paint binders present it as a potential binder which may be used in the coating industry.

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This work reports the extraction and application of tannins as wood-adhesives from Anogeissus leiocarpus plant using water, acetone or a mixture of these as solvent. In terms of the quantity of extracts from polyphenolic extract of Anogeissus leiocarpus bark, water was the most effective solvent, followed sequentially by acetone and solvent mixture (90% acetone and 10% water). The use of solvent mixture in tannin extraction yielded high tannin content. The poly condensation reaction of Anogeissus leiocarpus bark extract is influenced significantly by amount of formaldehyde (9.0 ml), tannin (2.5 g), glycerol (0.6 ml), cure temperature 80 O C, types and pH 7.5 of the adhesive medium. Adhesive joint of significant bond strength were obtained from Anogeissus leiocarpus tannin adhesive. Prolonged cure periods particularly at elevated temperature have adverse effect on the strength properties of these joints, especially with wood-panels as substrates. Joint prepared with adhesive derived from these extracts were tested for strength properties.

Graft copolymerization of polyacrylamide onto gum arabic was carried out in aqueous medium at room temperature (30 o C) using previously optimized concentrations of initiator (ceric ion) and the monomer (acrylamide). The percentage graft yield was high (70%) due to optimization of reaction conditions. Reactive blends of Moringa oleifera (MO) and the graft copolymer (GA-g-PAAM) were also synthesized in different ratios of MO to GAg -PAAM. The blended and unblended graft copolymers and Moringa oleifera were characterized by infrared (IR) spectroscopy. Flocculation capabilities of GAg -PAAM, the reactive blends (RB), the physical blends (PB) and Moringa oleifera were studied on turbid river water using UV-Visible spectrophotometry at three different wavelengths (λ=400, λ=600 and λ=800 nm) in order to observe the effect of wavelength on flocculation efficiency. The results generally showed that the flocculation efficiency was a function of both flocculation time allowed and the wavelength of UV-radiation used. Hence, the flocculation efficiency was higher for longer flocculation times and longer wavelengths of UV-radiation and vice versa. The flocculation efficiencies obtained after 24 hours at λ=800 nm followed the order below: MO (99.61%) > GAg -PAAM (94.30%) > MO & GAg -PAAM 3:1 RB (91.16%) > 1:3 RB (89.58%) > 1:1 PB (87.07%) > 1:1 RB (82.35%). The sludge produced by the above water treatment chemicals was small in volume, biodegradable and consequently did not promote environmental degradation. Through chemical derivatization, gum arabic was transformed into a water treatment chemical with more advantages over conventional coagulants.

Graft copolymerization of polyacrylamide onto gum arabic was carried out in aqueous medium at room temperature (30 o C) using various initiator (ceric ion) and monomer (acrylamide) concentrations. The extent of graft copolymer formation was determined in terms of percentage graft yield. The results obtained showed that the percentage yield of the graft copolymer is a function of both the initiator and monomer concentrations. The grafted copolymer was characterized by infrared (IR) spectroscopy. The IR spectral data for pure Gum Arabic (GA) and that of Gum Arabic-grafted Polyacrylamide (GA-g-PAAM) indicate that grafting actually occurred. The successful grafting of polyacrylamide onto gum arabic will enhance the search for materials transformation through chemical derivatization with attendant expansion of their spectra of application.