The New Age of Plastics

Busf Company of Germany, a booming plastics industry, added Schizophyllum commune to polymer materials to produce a new type of biopolymer. Researchers said that polymers obtained by chemical methods often have poor stability and will degrade under certain stress, while biopolymers have excellent stability and schizophyllin also has excellent high temperature resistance. The produced biopolymers can be used as thickeners to improve oil and gas recovery.
Plastics were put on the market in the early 19th century. Due to its advantages of stable chemical properties, low corrosion resistance, good insulation, good impact resistance and low processing cost, this organic synthetic polymer material gradually surpassed steel materials in terms of consumption volume and became the world’s largest industrial material.

However, in the past few decades, plastic products have been criticized by the mass media, and plastic packaging has also been branded as “white trash”. In people’s impression, the use of plastic products will not only cause waste of resources, but also cause damage to the environment. However, in fact, as long as the plastic products are properly recycled, instead of wasting resources, they can save resources and protect the environment-from an ecological point of view, plastic is an energy-saving and environment-friendly material.

|using plastic is more environmentally friendly |
A major factor in the generation of greenhouse gases is the burning of fossil fuels. By using plastic materials, the use of fossil fuels for industrial and domestic use can be reduced. For example, the use of high-efficiency insulation material PVC (polyvinyl chloride) in building barriers can reduce energy consumption by 9%. The use of plastic composite materials to manufacture parts of automobiles and airplanes will not only be more durable than traditional steel, but also reduce the weight of automobiles and airplanes, thus reducing transportation energy consumption. The weight of a car that uses all plastic composite parts can be reduced by 70%, the friction between the car tires and the road surface can be reduced, the energy consumption can be reduced, and the car is more energy-saving and environment-friendly than aluminum and steel.

According to the data of the United Nations Food and Agriculture Organization, about 1.3 billion tons of food worldwide rot every year due to lack of proper packaging. These discarded rotten food will cause great pollution to the environment, because for every kilogram of meat produced on average, more than 10 kilograms of carbon dioxide will be produced. For consumers, it is also a waste to buy food again. Plastic packaging, with its excellent oxygen barrier property, can prolong the shelf life of many foods, thus reducing food waste and greenhouse gas emissions.
In order to solve the current problem of shortage of petrochemical resources in the world, all countries in the world are developing renewable energy sources such as wind energy, solar energy, hydrogen energy, geothermal energy, etc., of which plastic is indispensable. For example, some key parts of industrial wind energy devices are made of plastic materials with high strength, light weight, durability and corrosion resistance, and the transportation and storage of hydrogen energy also depend on polymer materials.

|plastic combined with 3D printing technology |
With the gradual maturity of 3D printing technology, plastic materials can even be printed into human tissues and organs, which is also a major breakthrough in biomedical field. Last year, the Biomaterials Laboratory of the University of California in the United States created a bionic vascular network. The research team formed a bionic vascular tissue by encapsulating living cells with polymer materials and combining 3D printing technology. The bionic blood vessel network can supply blood to tissues and organs and transport nutrients, metabolites and other biological materials. It has been proved in the experiment of mice that the bionic blood vessel network can be successfully integrated with the blood vessel network of mice to make blood circulate normally.

Combined with 3D printing technology, Scripps Biomedical Research Institute of the United States used 3D printing technology to package human cells with polymer materials as raw materials to print bionic human skin, blood vessels and other human organs and tissues.

Drug targeted delivery polymer nanomaterials can be used as drug carriers to realize drug targeted delivery in human body. As shown in the figure, two polymer nanoparticles loaded with vaccines can pass through biological barriers that other macromolecular drugs are difficult to pass through, enter human organs and tissues, and deliver drugs to target cells in a targeted manner.

Also last year, a research team from the Swiss Federal Institute of Technology in Zurich created the world’s first soft artificial silicone heart. Researchers have synthesized the silicone material into an artificial heart through 3D printing technology. The artificial heart has the same internal structure as the real heart, and its beating is the same as the real one. The only disadvantage is that the life span is too short. The silicone heart will begin to decay after about 3000 beats, which is equivalent to only about 45 minutes. Therefore, it cannot be put into clinical application for the time being. However, this research still shows that the idea of combining plastic materials with 3D printing technology to synthesize artificial biological organs will have great development space in the future.

Combined with nanotechnology
The Nano Materials Laboratory of the University of Basque in Spain has developed a composite gel that can be used as a bone regeneration material to help patients with fracture, bone loss and osteoporosis to carry out effective regeneration treatment. At present, autologous bone transplantation is mainly used in clinical treatment of bone defects, but this traditional treatment method has the problems of high incidence and low acquisition rate of donor sites. Therefore, it is of great significance to find suitable bone tissue regeneration replacement materials for the treatment of bone defects.

Professor Golka Olivier of the laboratory said that they found gelatin nanoparticles had strong adhesion to bioactive glass particles when functionalized with bisphosphonic acid. The composite gel made from it can enhance bone density of osteoporotic bone tissue, induce proliferation and differentiation of peripheral cells, and stimulate regeneration of bone tissue at osteoporotic sites, thus playing a therapeutic role without any osteogenic supplement.
The new polymer nanomaterials can also be used as drug carriers to realize targeted drug delivery in human body. Many macromolecular drugs with biological activity are difficult to cross the biological barrier and enter human organs and tissues, but nanomaterials can do so. Polymer nanoparticles loaded with drugs can enter the human body through oral administration, subcutaneous injection, arterial injection, intravenous drip, etc. The drugs can be transmitted to spleen and bone marrow through liver endothelium or lymph, and even directly reach tumor tissues.
Combined with biotechnology

At present, polyethylene and polypropylene, two petroleum-based plastics, are still widely used in the world. Although the low-cost petroleum-based plastics have brought convenience to people’s lives, its degradation cycle of nearly several hundred years has imposed a certain burden on the ecological environment. Therefore, how to develop a degradable plastic that can replace petroleum-based plastics has become the focus of scientists’ attention in recent years.

The so-called degradation means being eaten by microorganisms and then entering the food chain for natural circulation. A new type of bio-plastic named PHA (polyhydroxy fatty acid ester) has attracted the attention of scientists due to its excellent degradability, which stands out among many kinds of plastic materials. PHA is a bio-based material synthesized by microorganisms. Its material properties are similar to those of traditional petroleum-based plastics and can play a substitute role in more than 50% of petroleum-based plastics application fields. Its biggest characteristic is that it can be decomposed by microorganisms in almost all environments (soil, seawater, compost), and it can be decomposed into carbon dioxide and oxygen in soil in only 3-6 months, without causing environmental pollution. It is an environment-friendly plastic material.

The above picture of cutting-edge nanomaterials is an artificial photosynthesis laboratory in the United States. Researchers follow the example of photosynthesis in nature and use nanoscale photo-sensitive materials to convert light energy into electric energy, thus generating oxidoreductase reaction, which is a technology that uses light energy to generate precise chemicals.

This nano-sensing material technology can also be applied to the human body. For example, on the left, a thin layer of nano-material is covered on the skin of the human body, and various vital signs of the human body are recorded by sensors.

In response to the energy shortage, plastics play an important role in the development of renewable energy fields such as wind energy, hydrogen energy, solar energy and geothermal energy, which can help people cope with the increasingly severe energy crisis. For example, the key parts of wind energy devices are made of plastic materials with high strength, light weight, durability and corrosion resistance.

As a new type of bio-plastic material, PHA can not only be made into plastic molds, plastic bottles and other plastic packages like traditional plastics, but also spun into fibers, which are applied to professional fields such as plastic surgery, bio-medicine and special packaging. In addition, PHA has good biocompatibility and can be used as surgical sutures, drug sustained-release carriers and transplants of human tissues.

Compared with traditional materials, bone nails, bone rods and other fixed framework materials made of PHA not only have enhancement effect, but also can promote the growth of human tissues. When new tissues grow out, PHA materials gradually degrade, and the decomposed products can be absorbed by human bodies without causing any adverse reactions. However, because the cost of PHA is 3 ~ 10 times higher than that of traditional polypropylene and polyethylene plastics, this bio-plastic has not been fully popularized and is currently mainly used in the field of bio-medicine.
Whether now or in the future, plastics are of great significance to mankind. We expect that with the rapid development of plastic technology, new plastic will make people’s living environment better.