The combined properties of low cost, lightweight, and resistance to chemicals and corrosion has increased the use of plastic materials for packaging and storage purposes in preference to other materials. Consequently, there is a continued increase in their proportion in domestic solid wastes worldwide as well as the concern of their impacts on the environment. Most developed and developing countries have put in place and continue to improve their plastic waste disposal, collection, and recycling methods to reduce these impacts. In Nigeria with a population of about 186 million, there are little or no available data on the use of plastic materials in relation to city populations, their disposal, collection, and recycling methods. There are a few numbers of plastic waste recycling companies in a fewer number of cities and disposal practices for the greater percentage of the plastic wastes that are not captured for recycling possess immediate and future danger for the environment. This work reviews the consumption of plastics, its waste generation, collection, and treatment in Nigeria and a few selected countries. The problems associated with inadequate management of the wastes were emphasized and recommendations were proffered to not only highlight research and investment opportunities that are inherent in plastic waste management in Nigeria, but also provide a background for the formulation of sustainable regulatory policies by the government to address the problems.

No abstract

No abstract

No abstract

The study reports on the effect of acetylation on the physicochemical parameters of Caladium bicolor starch. The starch was extracted and acetylated using various acetic acid volumes and reaction periods (30, 60, and 90 minutes). Both unmodified and acetylated starches were characterized with Fourier transform infrared spectrometry (FTIR) and some models. The findings estimated a low amylose content of 16.95%, and amylopectin at 83.05% in unmodified starch. The swelling power was 72.45 (unmodified), and 64.9–68.5 (modified); paste clarity was 2.013 (unmodified), and 1.73–1.91 (modified); gelatinization temperature was 75oC (unmodified), and 76–78oC (modified); water binding capacity was 68.6% (unmodified), and 68–92.7% (modified); oil binding capacity was 53.8% (unmodified), and 53.2–92.63% (modified); % acetyl group and degree of substitution were 0.73-3.63 and 0.03-0.13. The FTIR reveals the vibration frequencies of 3283.62 cm-1, 1018 cm-1 and 1240 cm-1 affirm the presence of OH, C-O, and CH3 in the unmodified. Whereas, the prominent peak at 1647.28 cm-1 assigned to the carbonyl C=O and its increase in intensity and height affirmed the increase in the acetylation of starch molecules. Starch obtained from Caladium bicolor and the acetylated products could be used as glue, thickeners, gelling agents and adhesives for paper products and textile industry.

Aminopyridines are among the classes of heterocyclic compounds that have been extensively studied in the last few decades owing to their interesting biological activities. They exist in three isomeric forms: 2-aminopyridine, 3-aminopyridine and 4-aminopyridine. The diversity in their pharmacological activities has attracted the attention of many researchers to explore the reasons for their wide potential. This study examines recent advances related to the efficient procedure for synthesizing different types of aminopyridine derivatives, its coordination site with metals and biological activities using systematic literature review and content analysis. Other important concepts of aminopyridines discussed are basicity, electric hindrance as related to percentage yield of isomeric forms and spectra updates on the characterization of aminopyridines. The findings from this study also reveal the array of solvents used for purification processes; ideas on isomers that have not been used in the synthesis of aminopyridine derivatives and their respective biological activities. The significance of this study is on the various synthetic methods revealed, which may be helpful to the development of newer compounds with aminopyridines moieties that could offer high bioactivity and lesser toxicity.

No abstract

No abstract