Bioplastics refer to plastics produced by microorganisms based on natural substances such as starch. It is renewable and therefore environmentally friendly. Relevant research has been carried out in many countries.
Prospect
A report points out that the global bioplastics market will grow rapidly, with an expected average annual growth rate of 8%-10%, increasing from US$1 billion in 2007 to US$10 billion in 2020. New applications in the automotive and electronics industries will drive growth in demand for bioplastics, although packaging will still dominate the market, with its share expected to decline from 65% in 2007 to 40% in 2025. By 2025, Asia will be the market leader in the bioplastics market, accounting for approximately 32% of the market, followed by Europe with 31% and the United States with 28%. Asia will occupy a leading position in the market, mainly based on the rapid development of genetically modified plants. In 2007, bioplastics accounted for approximately 10%-15% of the plastics market, and it is expected to reach 25%-30% by 2020. Mainly due to improvements in the technical performance of bioplastics, technological innovation will expand applications in the automotive, medical and electronic industries.
Bioplastics are not only environmentally friendly, but also adaptable to the human body. They are expected to be used in the production of medical products such as postoperative sutures that can be absorbed by the body.
In order to promote the use of renewable resources such as bioplastics, the Japanese government has issued the ” Biotechnology Strategic Outline” and the “Biomass Japan Comprehensive Strategy”, which mentioned that expanding the use of bioplastics is an important issue. The policy goal set in the “Biotechnology Strategic Outline” is that by 2010, 20% of plastics will be made from renewable resources.
Policy
1. The U.S. Department of Agriculture has encouraged the production of bioplastics by implementing the Procurement program since 2004 and plans to implement the BioPreferred program from 2010 to encourage consumers to actively consume biomass content. High biological products.
2. Belgium in Europe has launched the OKbiobased label to indicate the biobased content of bioplastic products and encourage consumers to consume green and environmentally friendly bioplastics.
3. Due to the short development time of bio-based materials in China, many products do not yet have standards and testing methods, and foreign standards and testing and evaluation systems were formulated relatively early. Therefore, in terms of bio-based content, biodegradation performance, etc., China’s products are exported We often encounter barriers. China’s biodegradable plastics industry is still in its infancy. It is still difficult for companies to make profits immediately. The acceptance of the market and consumers also needs a certain process. However, the environmental protection cause still needs the government to foot the bill.
Common plastics
From TV stands and computer frames to small ornaments and kitchen garbage bags, bioplastics can be found everywhere.
Self-destructive
Chemical plastic products not only bring various conveniences to human beings, but also bring unimaginable troubles to them. Because some waste plastics will not degrade under natural conditions, burning will release harmful gases, causing pollution to the ecological environment that is difficult to control. Therefore, scientists from various countries have begun to develop self-destructive or self-dissolving plastics that can decompose on their own to solve this problem. Some people call it ” green plastic “. Companies in many countries are launching their own bio- self-destructing plastics. Biologists at the University of Michigan in the United States first proposed the idea of ”planting” biodegradable plastics. They use potatoes and corn as raw materials and implant the genetic genes so that they can grow under artificial control to produce bioplastics that do not contain harmful ingredients. The American company Imperial Chemical Industries uses bacteria to make biodegradable plastics from sugars and organic acids. The method is similar to the fermentation process used to produce ethanol, except that the bacteria used are Alcaligenes, which converts the feed material into a plastic called PHBV. Bacteria accumulate this plastic as energy storage, just as humans and animals accumulate fat. When the bacteria accumulate 80% of their body weight in PHBV, steam is used to burst the cells and collect the plastic. PHBV has similar properties to polypropylene, and after disposal, this material is resistant even in humid environments.Stable, but in the presence of microorganisms it will degrade into carbon dioxide and water.
Microbiologists from the University of Göttingen in Germany isolated a specific gene of a bacterium to produce polyester inside plant cells. This type of polyester can be used to make plant-based biochemical plastics. This type of plastic is decomposed into water and carbon dioxide under the action of bacteria, so this plastic waste can be used as plant fertilizer and returned to nature. Scientists at the Japan Industrial Technology Research Institute used agricultural and forestry crop scraps, such as soybean straw, to make biodegradable agricultural films. Other scientists are experimenting with adding starch substances to plastics so that bacteria that feed on starch will eat them up and slowly disappear.
Biodestructible plastics have a wide range of medical uses. It acts as a support between bones during fracture surgery. As the bone heals, it gradually breaks down on its own. To treat broken fractures, doctors usually use nuts and screws made of stainless steel. Splints and drills were used to fix the broken bones. The disadvantage of this method is that it requires two surgeries, one to implant the stainless steel materials and one to remove them. Dutch scientists invented a plastic that decomposes into carbon dioxide and water after being implanted in the body for about two years. There is also a thread-shaped bio-self-destructible plastic that can replace traditional medical surgical threads to suture wounds. This kind of plastic surgical thread can be gradually absorbed by the body, eliminating the trouble of removing the stitches. In addition, medicinal capsules made of bio-self-destructible plastic will slowly dissolve in the body and can control the speed at which the drug enters the blood vessels.
Strong durability
The UK has developed a research project called Combine, which has developed a durable plastic. The plastic is not only strong and lightweight, but also environmentally friendly and can be used in car doors, boat hulls, baby incubators and similar products. The half-life of ordinary plastic is thousands of years. The plastic raw material studied in this project is made of plants, which has a short half-life and is a harmless synthetic plastic. It is also the first time that renewable resources are used to manufacture structural materials and products. Innovative Combination The aim of the Combine program is to develop a high-performance, bio-based composite that can be used as a structural component through an innovative combination of natural fibers and bioplastics. Today, the only natural fibers available are filled-formed staple fibers and compression-formed mat fibers, neither of which provide sufficient strength and stiffness to make structural components. Natural fiber yarns are often twisted together, which makes it difficult to inject sticky thermoplastic resin into them. In this plan, hemp and flax fibers are processed, spun into continuous fibers, and then woven into high-performance textiles. These textiles are combined with self-destructive bioplastics such as polylactic acid, and then formed into various parts through vacuum bagging and compression molding. Finally, surface treatment is required to strengthen the bond between the fiber and the resin. Material combination and processing technologies still need to be improved, and factors such as future environmental degradation, mixability and recyclability of materials must also be considered.
High temperature resistant type
A new type of bioplastic developed in Shanghai. Its heat resistance is greatly improved, with a heat distortion temperature exceeding 100°C. It can be widely used in disposable tableware, disposable medical supplies and other disposable appliances, packaging of electronic devices and other products, as well as agricultural films, pesticides and fertilizer slow-release materials, etc. agricultural field.
This new bioplastic, biodegradable polyester, uses an original production process and catalyst. Tested by the National Plastic Products Quality Supervision and Inspection Center, its degradation rate reached 62.1% after 94 days, meeting the national standard ’s definition of biodegradable plastics. This bioplastic can be blended with starch and other biological raw materials in a certain proportion to make various supplies. After these supplies are discarded, they become “food” for microorganisms in the soil, thereby achieving harmless decomposition.
Biomass plastic
A scientific research team led by Paul J. Dauenhauer of the University of Massachusetts Amherst has discovered a new method of producing biomass plastics. This method is low-cost and can use most biomass as raw materials at a high yield of 75%. The research results were published in the American Chemical Society ‘s “ACS Catalysis” journal. Paraxylene is used to make PET ( polyethylene terephthalate ) plastic, which is used in many products such as soda bottles, food packaging, synthetic clothing and even car parts. The plastics industry all uses petroleum as raw material to produce paraxylene; the new method can produce this chemical from biomass in a renewable way, and then produce plastic products marked with the triangular recycling mark “1#”. This method uses molecular sieves as catalysts to convert glucose into paraxylene through a three-step reaction in a high-temperature bioreactor. Since the nanostructure of the catalyst has a great influence on the biological reaction effect, this specially designed catalyst is the key to success. It has undergone a series of optimization and improvements to promote the reaction of paraxylene and increase the yield. This is a major breakthrough because other methods of producing renewable paraxylene are either expensive (such as fermentation) or have inefficient reactions and low product yields. In the future, this method can be further optimized to increase the yield of paraxylene and reduce costs. This discovery is a breakthrough for the Center for Catalysis for Innovative Energy (CCEI) research on the production of biofuels and chemicals from lignocellulosic biomass. part.
Advantages
1. Bioplastics can reduce the consumption of petroleum used to produce plastics;
2. Biodegradable plastics can promote slow progress in plastic recycling in the United States. According to the U.S. Environmental Protection Agency, only about 6% of plastics in the United States were recycled in 2005.
3. Bioplastics do not contain toxic substances such as polyvinyl chloride and phthalates. The impact of these toxins on health has received widespread attention, and some countries and regions have banned the addition of phthalates in toys and baby products.
4. The development of bioplastics are all obtained from pure plants. Plants contain a large amount of starch and protein, which are also the main sources of acrylic acid and polylactic acid in bioplastics. The acrylic acid and polylactic acid extracted from plants are then processed through various processes. The production of biodegradable plastic materials avoids pollution and damage to the environment to a large extent. This is an advantage that traditional plastics cannot match.
Determination of content
Due to technical problems, most bioplastic products are hybrid products of bioplastics and synthetic plastics. Having more biocontent means having more biocomponents that are more environmentally friendly, so differentiating consumer bioplastic products becomes even more important. The USDA ranks products with more biological ingredients higher than those with less. Belgium adopts star classification for biological products. Products with 20-30% bio-based ingredients are rated one star, 30-40% are rated two-star, and so on.
These policies are defined based on biocarbon content, evaluated as a percentage of biocarbon content and total carbon content. ASTM D6866 is a test method developed by the American Society for Testing and Materials to quantify the precise percentage of total biocarbon and fossil carbon content in test samples.
Research on various countries
Russia
As people’s awareness of environmental protection increases, the demand for bioplastics increases. Bioplastics do not require petroleum products and self-decompose after use. Polylactic acid is a raw material for manufacturing biopackaging materials. Bioplastics are 1-3 times more expensive than ordinary polymers made from petroleum products. Bioplastic packaging can effectively inhibit the penetration of oxygen, water vapor, and ultraviolet rays, and is heat-resistant. Despite the high cost of bioplastic products, the demand for biopackaging plastics is still growing rapidly.
Germany
The Biop manufacturer plans to build Europe’s first factory in Brandenburg to produce bioplastics from potato starch, with an annual production capacity of about 35,000 tons. The American company Natureworks produces more than 150,000 tons of corn plastic annually.
Belgium
Many shops use bioplastics to package fruits, vegetables and pastries.
France
In 2010, France will allow supermarkets to use only biodegradable paper bags.
USA
Biodegradable plastics have entered the mainstream market in the United States; although the cost of biodegradable plastics is still 10% or more higher than traditional plastics, manufacturers are finding that demand is growing, mainly due to the increased environmental awareness of consumers and the revision of environmental regulations. In addition, the increasing strength of biodegradable plastic products has brought good news to sanitation workers and pet owners who are well aware of the dangers of traditional plastics.
China
Dutch DSM invested US$20 million to establish Tianjin Guoyun Biomaterials Co., Ltd. in Tianjin, China, mainly for the construction of China’s largest polyhydroxyalkyl ester (PHA) polymer in the Tianjin Economic and Technological Development Zone. PHA is a new renewable polymer with a wide range of applications including automotive, biomedical and electronics, fibers, films and foams.
Facing problems
1. Price issue. Bioplastics are currently two to three times more expensive than ordinary plastics, which hinders the rapid popularity of this type of material. Some Japanese companies use bioplastics in their products, mainly to establish the company’s environmental image. However, once bioplastics enter the mass production stage, the cost can be greatly reduced.
2. Bioplastics, like biofuels, may compete with people for food. Biofuels come from corn, wheat and other food crops, which will drive up world food prices. Bioplastics based on corn and other raw materials may also cause the same problem. Scientists in Japan, the United States and other countries have begun to use waste wood, wild grass, etc. to make bioplastics.
3. The supply of bioplastics is still limited. Product prices remain driven to some extent by oil prices.
4. End-of-life management issues of bioplastics. The focus is on the problem of contamination of the regeneration stream by PLA bottles. Although current PLA levels do not yet pose a serious pollution threat, large numbers of PLA bottles would be harmful to the recycling economy of PET bottles.
5. There is a lack of unified labeling method for bioplastics.
6. Consumer awareness of bioplastics is increasing, but most consumers do not know how to identify these materials—such as biomaterials versus biodegradable materials, or renewable materials versus recycled content—and how to weigh different attributes. Therefore, it is important to strengthen publicity to consumers, such as accurately explaining the definitions of relevant terms. Additionally, consumers have little understanding of the best disposal routes for biodegradable materials. It is also important for the bioplastics industry to strengthen marketing to overcome the distrust of some consumers.
7. Global warming issue. Bioplastics can biodegrade to varying degrees, pointing the way for the world to no longer rely on petroleum to produce plastics. But manufacturers’ “green arguments” are complex and environmentalists have reservations about them. Producing bioplastics produces carbon dioxide, which contributes to global warming.
8. Doubts about the safety of genetically modified materials. The raw materials for bioplastics are crops—corn, switchgrass, sugar cane, even sweet potatoes —that require land and water to grow. To promote fermentation, manufacturers often use genetically modified organisms, and there are some drawbacks to recycling this plastic.
