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Introduction

A major problem being faced by the most industries is the non-biodegradability of most packaging materials being used (Popescu et al., 2017). The packaging market has commonly employed materials such as paper, glass, and metals to produce packages for several applications (Aryal, 2019). Nevertheless, these materials have been progressively substituted by plastic, which is lightweight, resistant to corrosion, presents excellent mechanical properties, is easy to process by common industrial equipment and is cheap (Gutiérrez, 2018). 

Plastics are polymer matrix (oil-based) containing additives which improves certain properties to aid processing (Scalenghe, 2018). This composition diversity reduces the ease of recycling. This is depicted in the accumulation of plastic wastes in landfill sites; as they have a retarded degradation rate (Chamas et al., 2020).

To generate a large waste volume, plastics take a rather absurd period of time; degrading the landfill sites in the process (Bano et al., 2017). There have been various approaches in recent years to eliminate the concerns of plastics degradation (Danso et al. 2019). Concepts like energy recovery, incineration and other modifications to the recycling process have been introduced (Garcia and Robertson, 2017). However, these modifications are relatively high cost investments (Kosior et al., 2018). Another “plastics problem” has been its continually hiked prices, as a result of the global increase in petroleum prices (Bhandari, 2018).

The environmental and economic problems from the non-biodegradability of plastics are promoting the development of biodegradable polymers whose degradation scarcely takes a few weeks and can be employed for the production of compost (Sagnelli et al., 2017) . Polysaccharides such as starches are very good examples of an alternative which offer several advantages for the replacement of synthetic polymers in plastics industries due to their low cost, non-toxicity, biodegradability, and availability (Fajardo et al., 2010; Simkovic, 2013).   

It is quite difficult to process starch-based, as they possess some peculiar properties such as brittleness, and they are also hydrophilic; in order to tackle these issues, some concepts have been developed. Some of the approaches are, multilayer structures with aliphatic polyesters, blends with natural rubber (Carmona et al., 2014) or blends with zein (Corradini et al., 2006) and composites with fibres (Rosa et al., 2009). Another approach that can be used to improve mechanical properties and processability of starch films is the addition of chitosan or chitin (Bergel et al., 2017).

An essential process for the production of biodegradable films with the starch-chitosan complex is “Casting” (Ginting et al., 2017). In this process, the starch would be pre-gelatinized before the chitosan is being added, and then fit into a mould. Industrially, this process is not feasible. Other notable processes have also been relatively neglected (Bajer et al., 2020).

Applications of chitosan/chitin blends are mostly in the pharmaceutical and biomedical fields according to literature (Zhang et al., 2020). To mention a few, chitosan is being used in drug delivery applications due to its capacity in enhancing the transport of hydrophilic drugs. The use of edibles films and composite coatings to extent the shelf life and improve the quality of fresh, frozen and fabricated foods has been examined during the past few years (Mujtaba et al., 2019). Chitosan has an excellent film forming properties, and has been used as food wrapping material (Hai et al., 2020). Chitosan has been also reported to be useful in nasal delivery and as a carrier in gene delivery (Silva et al., 2017). Several chitosan nano-composites were evaluated based on the ionotropic gelation (Ahmad et al., 2020).  In medicine and biomedical engineering, chitosan has been implemented in controlled systems for drug delivery due to certain significant properties they possess, most especially non-toxicity and their compatibility with biological systems (Las Heras et al., 2020).

Problem Statement

The biodegradability and bio-derivation of starch makes it an interesting polymer alternative to plastics due to its very low price. However, its poor mechanical properties and other intrinsic properties make it a limited choice for food packaging (Noorbakhsh-Soltani et al., 2018).

This study aims to overcome the poor mechanical properties of starch by first blending it with chitin and then synthesizing bio-composites by blending starch with chitosan.

Aim and Objectives

The aim of this study is to analyse the effect of composition on the mechanical properties of chitin/chitosan and starch blend. It has the following objectives;

• Objective 1:  Extraction of chitin and chitosan from fish scales.
• Objective 2:  Extraction of starch from cassava.
• Objective 3: Blending of chitin and starch with varying composition to form a composite (composition of starch constant).
• Objective 4:  Blending of chitosan and starch with varying composition forming another composite (composition of starch constant).
• Objective 5:  Carrying out a mechanical test on the composites to get the optimum composition.

Research Questions

The identified research questions for this project are provided below:

• How would the extraction of chitin and chitosan from fish scales be carried out?
• How would the extraction of starch from cassava be carried out?
• How would the intended bio-composite be formed?
• What is the optimum composition of the formed bio-composite? (Jha et al., 2018)

Deliverables

The deliverables of this project are a project report and obtained results.  Also, the report should contain a complete documentation of how the laboratory experiment was carried out, how the effect of composition on the mechanical properties of chitin/chitosan and starch blend was analysed, how various process variables were gotten, how the desired products were synthesized and how the results were arrived at.

Relevance

Due to the need for the replacement of non-biodegradable polymers with degradable ones, chitin/chitosan and starch blend is a biodegradable polymer that can be used in various sectors such as packaging industries (Verma et al., 2020).

The significance of this work is to get the optimum composition of chitin/chitosan and starch blend which will exhibit the best mechanical properties. Improving the mechanical properties of chitin/chitosan blend will help to enhance hydrophilicity, to enhance mechanical properties, to improve biocompatibility and to enhance antibacterial properties.

Methodology

This project focuses on secondary research, laboratory experiments and process analysis, and they are discussed below:

Secondary research

The secondary research in this project will utilize a systematic approach (Johnson et al., 2016) to review the works of literature. The steps involved in the systematic review of the literature are provided below:

• Step 1: Identify the research questions that can be used for the project.
• Step 2: Identify the keywords that should be used to research the works of literature.
• Step 3: Extract the journals and books that are appropriate for this project.
• Step 4: Write the literature review chapter.

Laboratory experiments

The laboratory experiments would cover a large chunk of this project. They would be carried out in stages, and as such described below;

• Stage 1:  Sourcing for the required input biopolymers and other required raw materials.
• Stage 2:  Developing an appropriate process route and optimal equipment arrangement for an efficient process setup (Zhang and Rolandi, 2017).
• Stage 3:  Carrying out the process reaction.
• Stage 4:  Analyzing the process reaction.
• Stage 5:  Varying the biopolymer and raw materials input.
• Stage 6:  Characterization of the resultant bio-composite.
• Stage 7:  Mechanical testing of the resultant bio-composite.

Process Analysis

The totality of the process reaction would be analyzed and this would also occur in stages;

• Stage 1:  Process Testing
• Stage 2:  Process Control
• Stage 3:  Process Optimization

Evaluation

The risk assessment conducted for this project is provided in the table below:

Table 1:  Risk assessment