Greening the Economy: Commercialization of Starch-based Bioplastics in Nigeria-A Review

A novel, robust mechanical strength, and naturally degradable double crosslinking starch-based bioplastics for practical applications

Nacre-inspired starch-based bioplastic with excellent mechanical strength and electromagnetic interference shielding

In this study, to make a good bioplastic composite, starch-based bioplastic is produced by adding polylactic acid (PLA) to improve its properties. PLA was added into starch-based bioplastic with various concentrations of 0, 3, and 10 wt.%. The extrusion was performed at 90-150 °C and compression moulding process was conducted at 150 °C and pressured at 50 kgf/cm2. Bioplastic composites have been characterized to know its properties. FTIR analysis indicated shifting and increasing spectra of interaction between PLA and starch-based bioplastic. Contact angle and solubility analysis revealed that adding PLA can increase the stability of hydrophobic characteristic and insoluble properties. The combination of PLA and starch-based bioplastic can improve the mechanical properties. In addition, thermal properties of bioplastic composites have a better thermal stability and produce a lower melting point thus the energy needed to melt for bioplastic composites becomes milt as raising PLA composition. The density of bioplastics was in the range of 1.2 - 1.3 g/cm3 that would be good for light bioplastic. The results of this study showed that the combination of starch-based bioplastics and PLA at low concentration (10wt.%) potentially could enhance the properties of bioplastic composites for food packaging.

BackgroundPlastic waste accumulation is one of the main ecological concerns in the past decades. A new generation of plastics that are easier to degrade in the environment compared to conventional plastics, such as starch-based bioplastics and oxo-biodegradable plastics, is perceived as a solution to this issue. However, the fate of these materials in the environment are unclear, and less is known about how their presence affect the microorganisms that may play a role in their biodegradation. In this study, we monitored the dynamics of bacterial community in soil upon introduction of commercial carrier bags claimed as biodegradable: cassava starch-based bioplastic and oxo-low-density polyethylene (oxo-LDPE). Each type of plastic bag was buried separately in compost soil and incubated for 30, 60, 90, and 120 days. Following incubation, soil pH and temperature as well as the weight of remaining plastics were measured. Bacterial diversity in soil attached to the surface of remaining plastics was analyzed using Illumina high-throughput sequencing of the V3-V4 region of 16SrRNA gene.ResultsAfter 120 days, the starch-based bioplastic weight has decreased by 74%, while the oxo-LDPE remained intact with only 3% weight reduction. The bacterial composition in soil fluctuated over time with or without the introduction of either type of plastic. While major bacterial phyla remained similar for all treatment in this study, different types of plastics led to different soil bacterial community structure. None of these bacteria were abundant continuously, but rather they emerged at specific time points. The introduction of plastics into soil increased not only the population of bacteria known for their ability to directly utilize plastic component for their growth, but also the abundance of those that may interact with direct degraders. Bacterial groups that are involved in nitrogen cycling also arose throughout burial.ConclusionsThe introduction of starch-based bioplastic and oxo-LDPE led to contrasting shift in soil bacterial population overtime, which may determine their fate in the environment.

Bioplastics are bio-based plastics from natural resources, made to replace conventional plastics. The utilization of biopolymers in bioplastics provide a faster degradation compared to petroleum-based plastics. Starch-based bioplastic from mixing Durio zibethinus Murr starch and glycerol as plasticizer have been conducted. In this research, the concentration of glycerol has been varied to study the effect on starch-based bioplastics mechanical properties. The tensile strength for Durio zibethinus Murr starch-based bioplastic with 20% glycerol was 50.28 MPa with 13.3% elongation. The functional group found on the Fourier transform infrared spectroscopy (FTIR) spectra indicated the presence of O-H stretch, C-H stretch, C=O stretch, and C-O stretch which stated the formation of bioplastic. The image results gained from scanning electron microscope (SEM) showed that the morphology surface of bioplastic was less homogenous and rough. The soil burial test for biodegradability showed Durio zibethinus Murr starch-based bioplastic achieved 38.9% weight loss in a 5-day observation.

While bioplastics are gaining wide interest in replacing conventional plastics, it is necessary to understand whether the treatment of the organic fraction of municipal solid waste (OFMSW) as an end-of-life option is compatible with their biodegradation and their possible role in shaping the microbial communities involved in the processes. In the present work, we assessed the microbiological impact of rigid polylactic acid (PLA) and starch-based bioplastics (SBB) spoons on the thermophilic anaerobic digestion and the aerobic composting of OFMSW under real plant conditions. In order to thoroughly evaluate the effect of PLA and SBB on the bacterial, archaeal, and fungal communities during the process, high-throughput sequencing (HTS) technology was carried out. The results suggest that bioplastics shape the communities’ structure, especially in the aerobic phase. Distinctive bacterial and fungal sequences were found for SBB compared to the positive control, which showed a more limited diversity. Mucor racemosus was especially abundant in composts from bioplastics’ treatment, whereas Penicillium roqueforti was found only in compost from PLA and Thermomyces lanuginosus in that from SBB. This work shed a light on the microbial communities involved in the OFMSW treatment with and without the presence of bioplastics, using a new approach to evaluate this end-of-life option.

In this work, starch-based bioplastics in advancing its properties were positively arranged with the addition of palm oil. Starch-based bioplastics were produced by dry blending method and compression technique with mixing starch and glycerol (3:1, w/w) then adding palm oil at various concentration (0%, 2.5%, 5% and 7.5% w/w). Morphology of bioplastics presented that palm oil wrapped bioplastics granules which influenced hydrophobicity properties of bioplastics compared by increasing contact angle of bioplastics from 45.95 0 (0% of palm oil) to 61.98 0 (5% of palm oil). This result indicated that the addition of palm oil could develop the properties of bioplastics to hold absorbing water molecules. Moreover, the melting point of bioplastics also affected shifting temperature from 115 0 C to be 100 0 C that could save the energy needed during heating process. FTIR analysis showed that C=O group at wavenumber 1747 cm -1 was dependable the interaction between starch-glycerol and palm oil. Furthermore, the addition of palm oil would accelerate the biodegradation process. Although the mechanical properties of bioplastics have not increased, the addition of palm oil on bioplastics fabrication is an alternative to improve the characteristic of bioplastics, especially physical, thermal, hydrophobicity and biodegradation properties.

Despite the promise of a reduced environmental impact, bioplastics are subjected to dispersion and accumulation similarly to traditional plastics, especially in marine and coastal environments. The environmental impact of bioplastics is attracting increasing attention due to the growing market demand. The ability of the supralittoral amphipod Talitrus saltator to ingest and survive on pristine starch-based bioplastic has already been assessed. However, the involvement of the gut microbiota of this key coastal species in making bioplastics a dietary supplement, remains unknown. In this study, we investigated the modification of T. saltator gut microbiota following bioplastic ingestion and the effect of this change on the modification of their chemical composition. Groups of adult amphipods were fed with: 1 - two different kinds of starch-based bioplastic; 2 - a 50%/50% chitosan-starch mixture; and 3 - paper and dry-fish-food. Freshly collected, unfed individuals were used as control group. Faecal pellets from the amphipods were collected and characterized using ATR-FTIR spectroscopy. DNA was extracted from gut samples for metagenomic analysis. Spectroscopic investigation suggested a partial digestion of polysaccharide components in the experimental polymeric materials. The analysis of the gut microbiota revealed that bioplastic feeding induced modification of sandhopper's gut microbial communities, shifting the abundance of specific microbial genera already present in the gut, towards bacterial genera associated with plastic/bioplastic degradation, especially in groups fed with starch-based bioplastics. Overall, our results highlight the involvement of T. saltator's gut microbiota in bioplastic modification, providing new insights into the potential role of microbial consortia associated to sandhoppers in bioplastic management.

This study provides an in-depth analysis of mechanical, thermal, and biodegradability characteristics of bioplastics: pure polylactic acid (PLA), starch-based bioplastics, and PLA-starch composites. Through tensile testing, elastic modulus evaluation, and thermal gravimetric analysis (TGA), alongside soil burial tests for biodegradability, this research aims to assess the performance and environmental impact of these materials. PLA demonstrated superior mechanical strength and thermal stability, whereas starch-based bioplastics exhibited higher biodegradability. PLA-starch composites offer a balanced approach, merging improved biodegradability with enhanced mechanical properties. This detailed evaluation aids in the informed selection of bioplastic materials for diverse applications.

In recent years, bioplastics have been making great strides in a promising way toward mitigating the damage that traditional plastics cause to the environment. This article discusses the status of cellulose and starch-based bioplastics in detail. To provide readers with helpful information, a variety of processes are analyzed, including polymerization, injection molding, film casting, 3D printing solvent-free methods, and electrospinning, along with prospects and challenges. This research also examines the numerous applications of bioplastics, including medical equipment, food packaging, textiles, and healthcare appliances with sustainable innovative concepts. In the end, the paper highlights a future outlook.

Starch-based bioplastics are promising sustainable alternatives to petroleum-based plastics; however, their limited mechanical strength and stability restrict broader packaging applications. This study investigates the influence of polyvinyl alcohol (PVA) content on the structural and functional properties of starch-based bioplastic films reinforced with chitosan and microcrystalline cellulose (MCC). Films prepared by solution casting with varying PVA compositions were characterized in terms of density, mechanical properties, thermal stability, biodegradation behavior, antibacterial activity, and structural features. Increasing PVA content produced denser film structures with improved tensile strength and thermal stability, while elongation at break reached its maximum at the intermediate formulation, indicating a strength–ductility trade-off. The control film exhibited antibacterial inhibition zones of 12.6 mm against Staphylococcus aureus and 8.8 mm against Escherichia coli, with activity decreasing at higher PVA content. These findings demonstrate that adjusting PVA composition effectively tailors the multifunctional performance of starch-based bioplastic films for sustainable packaging applications.

The use of plastics has increased due to the increase in population and applications in various industries. However, fossil fuel-based plastics have caused environmental issues and health hazards due to their non-degradable behavior. To resolve the on-going crisis of these non-degradable polymers, biopolymers have been considered as potential substitutes. Starch is being researched as a polymer matrix to develop bioplastics. Starch is abundant, but due to its poor water barrier and mechanical properties, other materials need to be incorporated in the matrix to improve the material properties. Natural fillers, plasticizers, essential oils, nanoparticles, or polymer blends are materials that can be used in starch-based bioplastics. Adding these materials enhances the mechanical and barrier properties. This review summarizes the recent developments in starch-based bioplastics and biocomposites and discusses the types of starch used, fillers, essential oils, and nanoparticles, explaining how they improve the mechanical, barrier, antibacterial, and biodegradability properties. Furthermore, many of the research products show potential to be used in industrial applications like packaging and agriculture. This review also discusses the potential of starch bioplastics in industrial applications like packaging, automotive applications, biomedical applications, electronics, construction, textiles, and consumer goods. This review also discusses the environmental impact of starch-derived bioplastic products, the life cycle, biodegradation, and recycling process. The circular economy of bioplastics, the economic feasibility of large-scale products, and regulation were also discussed, along with their challenges and the future perspectives of starch-based bioplastics.

Advanced of Starch-Based Bioplastics

Environmental, economic, and waste management concerns are growing as a result of the proliferation of plastics in the environment. As a potential solution to the problem of plastic pollution, glycerol plasticized starch-based bioplastics were investigated for their biodegradability. There are numerous uses of starch, a biopolymer derived from organic waste, due to its unique characteristics, such as its flexibility, degradable nature, and low cost. In the present work, starch was extracted from Solanum tuberosum (potato) peels, and starch-based bioplastics with different concentrations, i.e., 2.4 %, 24.3 %, 36.5 %, 48.6 %, and 97.2 % of glycerol plasticizer were prepared by following the casting method. Starch and bioplastics were analyzed using Fourier Transform Infrared (FTIR) spectroscopy, and their physicochemical properties were evaluated. The FTIR spectra of bioplastics with varying glycerol concentrations showed peaks at 3278 cm-1, 1643 cm-1, and 995 cm-1 corresponding to –OH, -C=O, and –C-O, respectively, confirming the formation of bioplastics. The water absorption test revealed that the bioplastic with high glycerol concentration, i.e., 97.2%, had a more significant percentage of water absorption, i.e., 79 percentage, compared to 37 % for bioplastic with low, i.e., 2.4% glycerol concentration. Water molecules enter more easily into plasticizer-rich materials, due to which bioplastic containing high glycerol concentration decays faster, i.e., in 52 days. Furthermore, a higher percentage of glycerol allowed the bioplastics to absorb acid solution for up to 42 hours and basic solution for up to 45 hours without being dissolved.

The depletion of fossil fuel resources and their associated effects, such as greenhouse gas emissions, global warming, and environmental pollution, have prompted researchers to explore the bioeconomy in innovative ways. The concepts of sustainability and the circular economy have shifted the focus of research from mere development to development that also prioritizes environmental protection, known as sustainable development. Conventional plastics, derived from petroleum, can take hundreds of years to degrade naturally, thus harming the local environment. Bioplastics, which are biopolymers sourced from biological materials, offer the advantage of biodegradability in natural environments and are considered a virtuous replacement for conventional plastics. Starch, an abundant and low-cost biopolymer, is a promising material for bioplastics. However, starch-based bioplastics often fall short in practical applications due to limited mechanical and barrier properties. Effective solutions include copolymerization, the addition of fillers, plasticization, and chemical modification. This review focuses on starch-based bioplastics, enhanced with cellulose, polylactic acid, and polyhydroxyalkanoates, and their applications in food packaging, medical, and electronic sectors.