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Research Publications (Engineering and Built Environment)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/215

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Subject: search.filters.subject.Polymer

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    Barrier and biodegradable properties of corn starch-derived biopolymer film filled with nanoclay fillers
    (SAGE Publications, 2016-12-18) Mohan, T. P.; Devchand, Kay; Kanny, Krishnan
    The objective of this work is to study the effect of nanoclay fillers on the biodegradation and barrier properties of corn starch polymer-based biofilm. Starch derived from corn plant source was used to prepare a biofilm by plasticization method. The barrier properties, namely, water absorption, moisture permeation, oxygen permeation and swelling of unfilled and nanoclay-filled corn starch biofilms were examined. The results indicate: ∼22% reduced water absorption, 40% reduced moisture uptake, 30% reduced oxygen permeation and 31% reduced swelling for 2–3 wt.% nanoclay-filled biofilm, when compared with unfilled biopolymer. The biodegradation result of unfilled and nanoclay-filled film series indicates that the nanoclay addition delays the biodegradation and is a function of nanoclay content in the film. The tensile, dynamic mechanical analysis and biodegradable studies were conducted on the biopolymers before and after water absorption, and the result shows that the nanoclay-filled biopolymer increased these properties when compared with unfilled biopolymer even after water absorption and is dependent on the nanocomposite structure and morphology as examined by X-ray diffraction and transmission electron microscopy analysis.
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    The efficiency of chitosan as a coagulant in the treatment of the effluents from the Sugar Industry
    (2015) Pambi, Ritha-Lorette Luti; Musonge, Paul
    Chitosan has been used as a coagulant for industrial wastewater treatment. However, no attention has been given to the coagulation of sugar effluents using this polymer. Two effluent streams from a local sugar refinery, namely the final effluent (FE) and the resin effluent (RE) were treated using chitosan prepared by dissolution in aqueous hydrochloric acid. The optimum chitosan dosage was found to be 138 mg/l and 7.41 mg/l for RE and FE respectively, beyond which, the efficiency of the coagulant decreased. The efficiency of the chitosan was higher under acidic conditions and using sodium hydroxide to adjust the pH negatively affected the performance of the chitosan. The treatment of FE yielded better removal efficiency (97% total suspended solids, 61% colour and 35% chemical oxygen demand) than RE (68% total suspended solids, 30% colour and 15% chemical oxygen demand). This coagulant can be used to pre-treat turbid water for further treatment.