Reinforced water hyacinth based biodegradable cutlery: Green alternative to single-use plastics

Abstract

Water hyacinth (WH) is an invading water plant that severely threatens biodiversity. The aim of this study was to utilize fibres from this underutilized plant to develop binderless biodegradable plates, in combination with different proportions (10%, 20% and 30%) of waste paper (WP), sugarcane leaf (SC), and banana stem fibre (BF), added as reinforcing agents. The properties of these products are compared with WH plates with starch as a binder (ST). The use of an epoxidized castor oil-based coating to enhance hydrophobicity was also studied. Analytical tests including functional group analysis, mechanical property, wettability, surface morphology, thermal stability and biodegradability studies were performed. It was observed that BF samples had the best mechanical properties, followed by SC, WP and ST, with BF-20 showing the maximum tensile strength (6.23 MPa) and elongation (10.09%). The thermogravimetric analysis showed the reinforced samples to be suitable for high-temperature applications, with SC-30 having a T5 value of 269.75 °C. The contact angles indicated that WH could be considered a suitable raw material for manufacturing biodegradable products with low wettability, and the addition of cellulose-rich reinforcing agents can further enhance its water resistance. SC-30 showed the highest hydrophobicity with a contact angle of 124.3°. Coating using an epoxidized castor oil-based solution can reduce the wettability of even super hydrophilic surfaces. All the samples showed good biodegradability, with most samples degrading completely within 20 days. Hence, water hyacinth reinforced with cellulose-rich reinforcing agents can be regarded as a superior raw material for manufacturing biodegradable cutlery.