An investigation on the use algae-based material for the production of reusable bioplastic bags: A Mauritian case study

Abstract

The Government of Mauritius has come up with new regulations in an attempt to ban the use of petroleum based plastics bags so as to protect the environment. Hence it is important to find substitute materials to achieve this goal set by the government. Interestingly though, Mauritius being an island with a large Exclusive Economic Zone (EEZ), there is an abundancy of seaweeds, which is an interesting avenue to explore. The unexploited seaweed in the waters surrounding Mauritius remains a remarkably potential raw material for the manufacture of an alternative to petro-plastics, especially polypropylene non-woven bags, in the form of reusable and fully biodegradable bioplastic bags. This research attempts to investigate the use of algae, mainly Gracilaria Salicornia and Ulva lactuca as a potential; raw material for the production of reusable bioplastic bags through Taguchi optimisation method for the culling of optimum constituent wt.%. For the preparation of the biofilm to be solution casted, cassava starch, algae powder, glycerol and acetic acid were selected as controllable factors. The Taguchi L9 orthogonal array experimental design plan was considered for carrying out the experiments. The responses analysed were the tensile strength, water absorption, biodegradation and water vapour permeability. A maximum tensile strength and degradation of 7.325 MPa and 91.32% respectively were achieved from Taguchi optimal conditions. A maximum water absorption and minimum water vapour permeability of 60.3 % and 3.0181 g/h.m² respectively were evaluated from the experiments. Contribution of factors to the responses were determined through analysis of variance. Furthermore, regression models and contour plots were developed for predicting the best combination which was determined to be 8 % (w/v) starch, 3 % (w/v) algae, 1 % (w/v) glycerol and 8 % (w/v) acetic. An Ulva lactuca blend was experimented to act as substitute for cassava starch, achieving a tensile strength and water absorption of 3.578 MPa and 175.0 % respectively. Compared to other materials, used for bag production, available on the market, the mechanical properties of the developed algae-based material showed its potential as a replacement with some having much higher tensile strength confirming its successful usage.