Plastics are a broad category of synthetic materials, and there are a number of different types. They can be moulded, extruded or pressed into solid objects. They are made from polymers, which are the main ingredient.
Commodity resins
There are a few different types of resins used in plastics. Some are cheaper and easier to process, while others have better mechanical properties. These can be a great alternative to engineered resins for applications where the cost is not as big of an issue.
Commodity plastics are used for a wide variety of products. They are inexpensive, easy to process, and are available in a high volume. Consumers use commodity resins to make everyday products like toys, food packaging, and clothing.
Engineered resins are typically used in applications that require high strength and heat resistance. For example, they are used in aerospace, automotive, and medical industries. A good engineered resin will have higher levels of elongation, impact strength, and corrosion resistance.
Commodity plastics include polypropylene, polyethylene, and polystyrene. Polypropylene is known for its machinability and chemical resistance, while polystyrene has similar characteristics.
Commodity resins are often used in plastic injection molding. While their mechanical qualities are not as important as those of the engineered resins, their affordability and high-volume production make them a viable option for processors.
Characteristics of synthetic polymers
Synthetic polymers are polymers that are created through chemical reactions in laboratories or factories. They are commonly made from petroleum oil and are produced through the polymerization process. These materials have a number of desirable properties, including good mechanical strength, resilience and chemical inertness.
Polyethylene is a popular synthetic polymer. It has good tear resistance, gas permeability and weather resistance. Another example is polyvinyl chloride (PVC). PVC was invented by a German chemist in 1872.
Another interesting polymer is poly(lactic acid) (PLLA). PLLA is a resorbable synthetic polymer with slow degradation kinetics. In addition, it is biocompatible and nonimmunogenic. PLLA can be used in tissue engineering applications, and it has been widely investigated for supporting high-strength tissues. PLLA scaffolds often exhibit higher modulus and lower elongation at break.
Molecular structure also plays a role in the final polymer. When synthetic polymers are manufactured, the chemical bonds holding monomers together are altered by heat and pressure. The final polymer can be a rigid polymer or a soft polymer with interesting properties.
Per capita GDP and plastics use
The production and use of plastics has a global impact. They can cause a host of environmental problems from toxic chemicals to groundwater contamination. Some may even choke animals. Plastics are also a major source of waste. To reduce the environmental impact of plastics, there are two main methods. One is to recycle the material, and the other is to dispose of it in an environmentally friendly manner.
One way to measure the impact of plastics is to look at the carbon footprint of their use. In 2015, the average global carbon footprint of plastics was 50 Mt CO2-equivalent. This is a bit smaller than the global population, but it still represents a substantial amount of carbon dioxide.
Generally, high-income regions contribute more to the carbon footprint than lower-income regions. High-income regions produce a high proportion of the plastics consumed by the world’s population. Their carbon footprints are projected to grow slightly in the next few decades.
A study by Washington State University looked at global trade in plastics. It found that although plastics are often recycled, there is still a lot of waste being dumped into landfills.
Microplastics
Microplastics are small plastic particles, typically less than five millimeters in length. These particles are found in a number of products. They can also be found in the sea, air and soil.
Plastics vary in size, shape, and chemical composition. The chemicals absorbed by plastics vary as well. Some chemicals are toxic to humans and animals.
Plastics can also harm marine life. In one study, microplastics were detected in the gut of a dead sperm whale that washed ashore in Sardinia, Italy.
Plastics can be introduced to the ocean by recreational and commercial fishing, fishing gear, and ships. These debris can be beached by currents and travel long distances.
Researchers have identified microplastics in the sea, air and even human tissue. Scientists are studying the impact of microplastics on wildlife and humans.
Plastics are known to affect animals’ endocrine system, which regulates hormone production. In addition, microplastics can block a fish’s gut, preventing it from feeding properly.
Studies have also found that the lymphatic system of animals, which regulates the elimination of bodily toxins, is affected by chemicals in microplastics. This can lead to increased mortality.