Characterization of bioplastics produced from yam and potato peels using hydrochloric and acetic acids

The calls for green biodegradable plastics to replace synthetic ones are continuously growing amidst the current environmental threats. These threats are evident all over the globe as seen from heat waves, floods, earthquakes, glacier melts, etc. This research presents morphological, physical, mechanical, and thermal properties of bioplastics produced from yam and potato tuber peels. This alternative to synthetic plastic materials serves to mitigate the menace posed by plastic waste and hence provides a sustainable environmental solution. Waste yam peels (WYP) and waste potato peels (WPP) were obtained from eateries, then washed, dried, and ground before the starch extraction. The starch was then used to produce bioplastics in the presence of hydrochloric (HCl) and acetic acid. Analysis was carried out on the morphological, qualitative, physical, mechanical, and thermal properties of the material. It was observed that bioplastic produce using HCl was darker than those produced by acetic acid while WYP bioplastics were rougher on the surface than WPP. FTIR spectra also revealed higher peaks in polyester fingerprint bioplastic hence the effect on physical, mechanical, and thermal properties. The bioplastics recorded densities between 1.2 and 1.7 g/cm 3 ; HCl-based bioplastics exhibited denser properties compared to acetic acid based. While WPP bioplastic generally exhibited less water absorption capacity, HCl-based bioplastics also recorded lower water absorption for the same starch. HCl-based bioplastic recorded a higher modulus of elasticity (MOE) compared to acetic-based bioplastic. WPP produced via HCl recorded the highest MOE of 0.09 N/mm 2 , which is 350% higher than potato and acetic acid. The bioplastics produced exhibited two stages of thermal degradation. The WPP bioplastic exhibited a thermally more stable behavior even though the yam-based bioplastic recorded an earlier onset of thermal degradation. Among the bioplastics produced, WPP-HCl exhibited the best in physical, mechanical, and thermal properties. While all these waste peels bioplastics show promising properties, it gives the bioplastics an advantage in application related to edible foods packaging.