Woven and nonwoven flax fiber reinforced poly lactic acid (PLA) biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM). Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive), biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site

Using deletion typing technique, five mycobacteria isolated from unpasteurised milk samples from cows in north-central Nigeria were characterized as Mycobacterium bovis (n=4) and M. africanum (n=1). This report emphasizes that transmission between the animal and human reservoir is a serious threat in Nigeria.

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Biocomposites were successfully prepared by reinforcing polylactic acid with flax fibres (PF). To improve the interfacial adhesion between the matrix and the fibres, amphiphilic compounds as additives were introduced. Structural and thermal characterisations of the PF were performed by Fourier transform infrared spectra, differential scanning calorimetry and thermogravimetric analysis. The interfacial adhesion between the fibres and the matrix was visually assessed from the SEM images of fractured specimens. Dynamic mechanicalthermal analysis was performed to evaluate the damping behaviour of the composites and thereby to interpret the interfacial adhesion between fibres and the matrix. It was observed that in the case of mandelic acid, particles/spheres were generated, resulting in effective stress transfer from the matrix resins to flax fibres, thereby increasing the storage modulus and impact strength of the composites. Mechanical properties and the water uptake of the composites with amphiphilic additives have also been reported.

The synthesis of a series of 3-(p-substituted phenylazo)-6-pyridone dyes which is suitable for the dyeing of polyester fabrics, is described. Visible absorption spectra of the dyes were examined in various solvents and the compounds in solution exhibited hydrazone-common anion equilibrium. The electronic absorption spectra cover a λ max range of 404-464 nm in DMF at uniformly high absorption intensity between 5.33 × 10 4-8.55 × 10 4 l•mol-1 •cm-1 and gave bright intense hues of yellow to orange on polyester fabrics. The colour parameters of the dyed fabrics were measured and the dyes have excellent exhaustion between 72%-79% for polyester fabrics, more intense and of very good fastness properties on polyester fabrics. The remarkable degree of levelness and brightness after washing is indicative of good penetration and excellent affinity of these dyes for the polyester fabric.

The influence of alkaline aqueous solution treatment of groundnut shell-high density polyethylene composites consist of magnesium hydroxide as flame-retardant additives was investigated. FTT daul cone calorimetry and PerkinElmer Diamond differential scanning calorimetry (DSC) were used to characterize flammability and thermal properties of the fabricated composites. Quanta 200ESEM was used to investigate the effect of alkaline aqueous solution treatment on the microstructure of the composites. The result obtained revealed that the alkaline treatment of the shell enhanced filler-matrix compatibility. The cone calorimetry result revealed that Mg(OH) 2 has good fire retardancy characteristics on the fabricated composites as properties such as heat release rate, effective heat of combustion, mass loss rate, total smoke produced, and specific extinction area were enhanced. DSC results suggested that the additives had little impact on the melting temperature of the composite.KEY WORDS: high-density polyethylene (HDPE), flame retardant, melting point, heat of fusion, flame zone, flame poisoning, system A(unfilled sample), system B(untreated groundnut shell À HDPE þ Mg(OH) 2 ), system C(treated groundnut shell À HDPE þ Mg(OH) 2 )

An active methylene compound, malononitrile, was introduced into the structures of a series of disperse dyes previously prepared by coupling phloroglucinol, barbituric acid, andαandβ-naphtho to 4-amino-3-nitrobenzaldehyde. The dyes were purified by recrystallization from ethanol. The purity of the dyes was examined by thin-layer chromatography (TLC) and the dyes were characterized by visible absorption and Fourier transform infrared spectroscopy (FTIR). The malononitrile-condensed dyes produced deeper colours and shades with better fastness to wash, light, and perspiration on application to polyester and nylon fabrics when compared to their uncondensed analogue.

In this work, thermosetting resin, epoxy and fibre loading were used in optimizing the strength at which ABS/epoxy coated kenaf fibre (EKF) composites would perform apparently during mechanical stress. Kenaf bast fibres were resin coated before incorporated into engineering thermoplastic ABS at its processing temperature (230˚C), cured in-situ at internal mixer and later compression moulded at 210˚C under 65 kg/cm 2 pressure. The results showed the optimum level of tensile strength with thermoset and fibre loading as well as increase in strong interfacial bonding while the hardness values increased with increasing thermosetting and fibre contents. Both the tensile and flexural modulus apparently increased as the fibre contents increased.