Formulation of Emulsion Paint from a Copolymer Composite of Dimethylol Urea/Polystyrene

Dimethylol urea (DMU) with reduced formaldehyde emission was synthesized in this work and copolymerized by blending with polystyrene (PS) obtained by constituting waste expanded polystyrene into liquid form. The determined physical properties of the copolymer composite (i.e. DMU/PS) compared to the pure DMU revealed improvements in its disadvantageous properties such as hardness and moisture uptake. Paint samples were formulated using the pure DMU, DMU/PS and commercially obtained acrylic PVA binder resin, and analyzed. While the DMU/PS and APVA paints passed, the pure DMU failed such critical coating tests as flexibility, adhesion and blistering. Again, the DMU/PS and PVA paints show good chemical resistance while the DMU paint blisters in the alkaline medium. However, all paint samples passed tackiness, opacity and stability, and exhibit acceptable pH, viscosity, and drying time. Keywords: Dimethylol urea, Polystyrenes, Copolymer composite, Emulsion pain

Studies on the adsorption efficiency of activated carbon for pesticide vapour

Chlorpyrifos pesticides are endocrine disruptors, inhibitors of acetyl cholinesterase, used to control pests and prime contributors to indoor pollution in retail stores. Seven selected locally sourced adsorbents; Bone charcoal (BCA), corncobs, cotton seed, kokoli, sawdust, coconut shell (CSA) and Muruchi were evaluated. Only BCA and CSA shows peaks and were further examined at adsorptive temperatures of 283, 293, 303, and 313K. Adsorbents physical properties that is, micro pore surface area, total pore volume; micro pore volume, particle density and true density were measured and compared. Results from gas chromatography and surface characterization revealed that the adsorptive capacities of carbon (CSA) at various temperatures were higher than that of carbon (BCA). The plots of Langmuir and Freundlich Isotherms were well fitted by the measured adsorption data. The parameters of adsorption equation for both Langmuir and Freundlich were determined for the two adsorbents, which indicates increased values of adsorptive capacity at low temperature and decreases at high temperature. This study shows that activated carbon made from coconut shell has high surface area, micro porous structure, high degree of surface reactivity and higher heterogeneous properties that suggest it to be a better adsorbent sufficient for the adsorption of chlorpyrifos vapour in an indoor environment

Structural Modification of Cellulosic Fabric via Esterification Using Jatropha curcas Seed Oil

This paper presents the results of x-ray diffraction of a cellulose fabric treated with oils extracted from the seed of Jatropha curcas; the oils were extracted with hexane under reflux while the fabric was purified by scouring, bleaching and mercerization to remove dirt and coloring matter in order to make it suitable for esterification. Apart from the controlled sample which was un-esterified, other samples of the same fabric were treated with different volume and concentration of the oil under the same temperature. The x-ray diffraction analysis carried out on all samples showed that while the control sample had a sharp single peak at 24.033° all the esterified samples showed broad split peaks at angles ranging from 20.308o to 22.809o; also while the control sample had inter-atomic (or d-spacing) of 3.702 Å those of the treated sample ranged from 3.8984 Å to 4.3727 Å, in addition to these the peak width increased from 1.5o in the control sample to between 1.9o to 2.8o in the treated samples. Other significant results showed that the peaks intensity increased from 5489 to highest value 8313 in the sample treated with 20 cm3 of oil. Crystallinity was observed to reduce from 65% in the control to about 63% for esterified fabrics samples and lastly, crystallite size reduced from 9.9 nm to between 5.3 nm to 7.7 nm. The observed structural modifications in treated fabric may have direct influence on the physical, mechanical properties as well as dye-ability of the treated samples. The result of water Imbibition also revealed structural modification as there was a decrease in the amount of water imbibed by esterified fabric, indicating a reduction in the number of OH groups in the new cellulose derivative as revealed in the x – ray analysis. Hence the esterified fabric will be less susceptible to microbial attack during storage

Graft copolymerization of Acrylamide onto Bombax Costatum Calyx by initiator ceric ammonium nitrate: Study of effective grafting parameters for optimization

Abstract: The Graft copolymerization of Acrylamide monomer (AAm

Utilization of amino resin for emulsion paint formulation: Effect of urea formaldehyde viscosity on urea formaldehyde and soybean oil copolymer composite

In our continuous desire to develop a paint binder from amino resin, the effect of urea formaldehyde (UF) viscosity on a copolymer composite derived from the copolymerization reaction between urea formaldehyde (UF) and soybean oil (SBO) to give urea formaldehyde/ soybean oil copolymer composite (UF/SBO) was investigated. Some physical properties of (UF/SBO) obtained at different viscosities (5.11 -260.04 mPa.s) were evaluated. The melting point, density and formaldehyde emission were found to increase with increase in UF viscosity while the dry time, moisture uptake refractive index and elongation at break were found to decrease with increase in UF viscosity. UF viscosity below 150.00 mPa.s was found to produce UF/SBO copolymer composite that is soluble in water. The processing of UF/SBO copolymer resin for emulsion paint formulation should be carried out below this viscosity level. The copolymer composite was found to be ductile throughout the viscosity range studied (5.11 -260.04). This takes care of the inherent brittleness associated with the traditional UF and will give paint formulators freedom of choice as regards processing viscosity of UF/SBO. The results obtained from this experiment will offer formulator different options and to control formulation processes towards developing UF/SBO copolymer composite as a paint binder for emulsion paint formulation

Studies on the chemical composition and physico-chemical properties of the seeds of baobab (Adasonia digitata

The seeds of baobab used in preparation of local condiments was analysed to establish the proximate composition and the physico-chemical characteristics of the oil and effect of storage on the oil. Results obtained showed that the saponification value (SV), iodine value (IV), peroxide value (PV), acid value (AV), percentage free fatty acid (%FFA) and refractive index of the oil are 196 ± ± ± ± 0.05 mg/KOH, 87 ± ± ± ± 0.02 g/100 g, 4.5 ± ± ± ± 0.06 mEq/kg, 0.33 ± ± ± ± 0.03 mgKOH/g, 0.45 ± ± ± ± 0.08 and 1.459 ± ± ± ± 0.13, respectively. Proximate analysis showed that protein (21.75 ± ± ± ± 0.12 g/100 g), ash (5.01 ± ± ± ± 0.07 g/100 g) and fiber (6.71 ± ± ± ± 0.003 g/100 g) were comparable to Prosopsis africana seeds (20.54 ± ± ± ± 0.18, 6.67 ± ± ± ± 0.08 and 5.51 g/100g), which is used for the same purpose. The crude lipid content (12.72 ± ± ± ± 0.01 g/100 g) was almost equal to that of P. africana seeds (12.74 g/100 g). The major mineral elements present in the seeds included phosphorus, calcium and potassium (6.00 ± ± ± ± 0.02, 58.90 ± ± ± ± 2.34 and 280.00 ± ± ± ± 1.34 mg/100 g, respectively), thereby suggesting that the baobab seeds could contribute partially to the overall daily intake of these elements. The vitamins (A and C) found present in baobab seeds are higher than that of P. africana seeds. The antinutritional factors including oxalate, phytate, saponin and tannin (10.31 ± ± ± ± 1.00, 2.00 ± ± ± ± 0.31, 7.16 ± ± ± ± 0.01, 2.84 ± ± ± ± 0.30%, respectively) are also comparable to that of P. Africana. The storage property of the oil from baobab seeds studied over a period of four weeks under conditions of light (ambient), darkness (ambient), and refrigeration showed that 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, thus indicating that the oil can withstand storage