bioplastic
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What is bioplastic?
Bioplastic is a moldable plastic made from renewable resources, synthesized by microbes or genetically modified plants, unlike traditional petroleum-based plastics. While conventional plastics persist for hundreds of years, bioplastics offer a more sustainable alternative, with some being biodegradable.
The first bioplastic, polyhydroxybutyrate (PHB), was discovered in 1926. Interest in bioplastics grew due to the petroleum crisis of the mid-1970s, and research expanded with the rise of molecular genetics.
Though bioplastics represent a small fraction of plastic production due to high costs and low yields, metabolic and genetic engineering improvements could boost production and lower costs. Rising oil prices and environmental awareness may further expand the bioplastics market.
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How is bioplastic different from regular plastic?
Bioplastics are moldable materials derived from renewable resources like microbes or genetically modified plants, whereas traditional plastics are derived from petroleum. Unlike traditional plastics, some bioplastics are biodegradable. Traditional plastics are generally not biodegradable and break down into microplastics, which persist in the environment for centuries.
While conventional plastics rely on chemical extraction and synthesis from petroleum, bioplastics are synthesized by microbes or produced from plant-derived sugars and starches. The degradation products of bioplastics are natural metabolites, making them of interest in medical applications, such as absorbable surgical sutures.
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What materials are used to make bioplastics?
Bioplastics are moldable plastic materials made from chemical compounds that are either derived from or synthesized by microbes, like bacteria, or from genetically modified plants. Unlike traditional plastics, which derive from petroleum, bioplastics are obtained from renewable resources.
Common bioplastics include polyhydroxybutyrate (PHB) and polyhydroxyalkanoate (PHA), both synthesized within specialized microbes, and polylactic acid (PLA), which is polymerized from lactic acid monomers produced by microbial fermentation of plant-derived sugars and starches. The major sources of starch are tubers, such as potatoes and cassava, and cereals.
Some bioplastics are biodegradable, but some break down only with industrial processing.
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How are bioplastics made from plants or other biological sources?
Bioplastics are moldable plastic materials made from chemical compounds that are either derived from or synthesized by microbes, such as bacteria, or from genetically modified plants. Unlike traditional plastics, which come from petroleum, bioplastics are made from renewable resources, and some can break down naturally.
The first bioplastic was polyhydroxybutyrate (PHB), discovered in 1926. Other bioplastics include polyhydroxyalkanoate (PHA) and polylactic acid (PLA). PLA is made from lactic acid monomers produced by microbial fermentation of plant-derived sugars and starches.
Some bioplastics that are labelled as biodegradable only break down through industrial processing. Researchers are also exploring new bioplastics made from materials like powdered cyanobacteria cells and thermoplastic starch, which can degrade at rates comparable to common organic waste in compost bins.
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What are some common uses of bioplastics today?
Bioplastics are moldable plastic materials derived from renewable resources like microbes or genetically modified plants, offering a sustainable alternative to traditional petroleum-based plastics.
Common uses of bioplastics today include:
* Packaging: Bioplastics are fabricated into biodegradable bottles and packaging films.
* Medicine: They are used in controlled-release drug packaging and absorbable surgical sutures because their degradation products are natural metabolites.
* Environmental Management: Some bacteria can produce biodegradable plastics, and the transfer of that ability to microbes that can be easily grown in the laboratory may enable the wide-scale "greening" of the plastics industry.
* Biomaterials: Some thermoplastic biomaterials, such as polylactic acid and polyglycolic acid, are polymers based on a repeating amino acid subunit and have applications in absorbable sutures and drug-release systems.4 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are the benefits and challenges of using bioplastics for the environment?
Bioplastics are plastic materials made from renewable resources like microbes or genetically modified plants, offering an alternative to traditional petroleum-based plastics. Some bioplastics are biodegradable, addressing the environmental concerns of plastic pollution and microplastics.
Benefits: Bioplastics can reduce reliance on finite petroleum resources and decrease harmful pollution. Their degradation products are natural metabolites, making them suitable for medical applications like drug packaging and surgical sutures.
Challenges: High production costs and stability issues have hindered large-scale success. Also, not every bioplastic is biodegradable, and some require industrial processing to break down. Ensuring proper diversion from landfills to facilitate biodegradation poses logistical challenges.
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bioplastic, moldable plastic material made up of chemical compounds that are derived from or synthesized by microbes such as bacteria or by genetically modified plants. Unlike traditional plastics, which are derived from petroleum, bioplastics are obtained from renewable resources, and some bioplastics are biodegradable.
Plastics are polymers—assemblies of identical chemical subunits, called monomers, that are linked together in the form of a chain. The properties of a plastic, like those of all polymers, are defined by the monomers in the chain and by the number of links and cross-links in its structure. Cross-linking of the monomers increases a polymer’s rigidity and thermal stability. As their name suggests, plastics can readily be molded into various shapes. Plastics such as polystyrene (polymerized styrene, CH2=CHC6H5), polyethylene (polymerized ethylene, CH2=CH2), or polypropylene (polymerized propylene, CH2=CHCH3) are molded into a wide variety of everyday and specialized products—for instance, eating utensils, coffee cups, synthetic fabrics, park benches, automobile parts, and surgical implants.
Since the early 20th century, there has been an explosion in the development and use of plastics, and their utility and importance have become so great that it is difficult to imagine modern life without them. Virtually all current plastics are derived from petroleum through chemical extraction and synthesis. Because petroleum-based plastics are generally not biodegradable, plastic refuse is very durable, and disposing of it has become a serious problem. Despite efforts to encourage and support recycling, landfills are becoming filled with plastic refuse and plastic pollution is a harmful and unsightly form of land and water pollution, Many conventional plastics degrade into microplastics, which can accumulate in living tissues and are now found in nearly every environment on Earth. An additional problem with petroleum-based plastics is that petroleum resources are finite; conservative sources estimate that at current rates of consumption, all known conventional sources of petroleum on Earth will have been depleted before the end of the 21st century (see also peak oil theory). Given that modern life is dependent on plastics, that petroleum is a nonrenewable resource, and that petroleum-derived plastic waste fouls the environment, a sustainable solution for the longer term may be found in bioplastics.
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The first known bioplastic, polyhydroxybutyrate (PHB), was discovered in 1926 by a French researcher, Maurice Lemoigne, from his work with the bacterium Bacillus megaterium. The significance of Lemoigne’s discovery was overlooked for many decades, in large part because, at the time, petroleum was inexpensive and abundant. The petroleum crisis of the mid-1970s brought renewed interest in finding alternatives to petroleum-based products. The rise of molecular genetics and recombinant DNA technology after that time further spurred research, so that by the beginning of the 21st century the structures, methods of production, and applications for numerous types of bioplastics had become established. Bioplastics that were either in use or under study included PHB and polyhydroxyalkanoate (PHA), both of which are synthesized within specialized microbes, as well as polylactic acid (PLA), which is polymerized from lactic acid monomers produced by microbial fermentation of plant-derived sugars and starches. Degradation of the chemical links between the monomers in these plastics is brought about by microorganisms or by water, making bioplastics highly desirable materials for fabrication into biodegradable bottles and packaging film. However, given that biodegradation is deliberately minimized in most sanitary landfills, the diversion of biodegradable plastics from the traditional waste stream remains a logistical challenge.
Because the degradation products of such plastics are natural metabolites, the polymers are also of interest in medical applications, such as controlled-release drug packaging and absorbable surgical sutures.
Bioplastics currently make up an insignificant portion of total world production of plastics. Commercial manufacturing processes are plagued by low yields and are expensive. However, improvements in metabolic and genetic engineering have produced strains of microbes and plants that may significantly improve yields and production capabilities while reducing overall costs. These factors, when added to increasing oil prices and growing environmental awareness, may expand the market for bioplastics in the future.