When you go out for shopping, you will probably use a plastic bag for packaging your items. Similarly, when viewing your TV, using a computer, riding a bus, plastics are involved.
In other words, we are surrounded by plastics, and almost everything humankind uses is plastic.
Then, you may ask yourself what the origins of plastics are, how it is made, and the various types of plastics.
Though plastic is a general term, there are many types with different uses. This article seeks to explain what plastic is, its origin, types of plastics, and everything you need to know about plastics.
Plastics are human-made materials made from long chains of molecules of carbon and hydrogen called polymers.
Initially, the word plastic meant easily shaped and flexible. They have developed from natural plastic materials use, which dates back in the 1600BC.
It then advanced in the 19th century with the use of chemically improved natural materials, during the industrial revolution.
Finally, there was the first invention of synthetic plastic in 1869 by John Wesley Hyatt, a plastic called celluloid. Since then, new developments occur every day regarding plastics.
Types of Plastics
Plastics are of various types depending on properties. There are three main types which are thermoplastics, thermosets, and elastomers.
Thermoplastics refer to plastic polymer materials that become moldable and solidifies on cooling.
These polymers have weak bonds that easily break when exposed to high temperatures resulting in a gluey liquid.
Once the heat is removed, they reform back quickly. While thermoplastics are in the viscous liquid state, you can reshape them.
They are used to produce parts by several polymers using techniques such as extrusion and injection molding. They do not melt upon exposure to high temperatures and decompose upon cooling.
Examples of thermoplastic plastics include:
- Polyvinylchloride (PVC)
- Polyamide (nylon)
Thermosets, also known as thermosetting, are plastic made by polymers joined by chemical bonds, thus attaining a strongly cross-linked structure.
The robust construction makes this plastic highly mechanical and sturdy. Therefore, you cannot reform or remold them in high temperatures.
Additionally, the cross-linked structure makes thermosets reduce their elasticity. They are frequently used to make auto spare parts, tires, and aircraft parts.
Examples of thermosets plastics include:
- Polytetrafluoroethylene (PTFE)
- Epoxy resin
These are polymers joined with weak intermolecular forces and have viscosity and elastic properties.
Due to the uncertain effects, they are easily deformed, stretched, and twisted at room temperature.
After cooling to a crystalline state, an elastomer resumes back the original form and shape, and its elasticity reduces.
They are of two types, saturated elastomers ad unsaturated elastomers. Examples of elastomers are:
- Polysiloxanes (Silicone rubber)
Examples of Well-Known Plastics
Plastic is a general term for polymers. There are many examples of compounds that are plastic. However, though there are many examples, here are some of the well-known plastics.
1. Polyethylene terephthalate (PETE or PET)
PET is a polymer that belongs to the polyester family. Its production is by polymerization of terephthalic acid and ethylene glycol.
The two are heated together in the influence of catalysts to produce molten PET.
The main uses of this plastic are in making throwaway beverage bottles, magnetic recording tapes, and photographic films.
Also used in making artificial silk, carpets, and belts. It is recyclable plastic. An example of polyethylene terephthalate is acetaldehyde. Find out more about faucet water filters here.
2. Polypropylene (PP)
Polypropylene, also referred to as polypropene, is a thermoplastic polymer formed by polymerization of propylene monomers.
You can manufacture PP by thermoforming or injection molding in living hinges. These hinges do not break when bent.
There are various applications where you can use PP. They include making plastic parts for automotive industries, textiles, and making packaging products.
3. Polyethylene or polythene (PE)
Polythene among the most common thermoplastic material with a chemical formula (C2 H4) n.
From plastic bags, bottles, to plastic toys, most of these items are created from polyethylene. Manufacture of PE is by polymerization of ethane monomers.
Examples of PE are chlorinated polyethylene (CPE) and high-density polyethylene (HDPE).
4. Polyvinyl chloride (PVC)
PVC is a thermoplastic polymer made by combining many molecules of vinyl chloride.
It is known to be hard and generally durable. There are many products made by PVC, such as window frames, roofing sheets, wall coverings, and automotive products.
Also used in making medical products such as surgical gloves and transfusion tubes.
5. Polystyrene (PS)
Polystyrene is a hard synthetic plastic produced by polymerization of styrene.
When heated, it softens transforming into various products such as sheets and films.
PS, used in making plastic cups, kitchen appliances, toys, hairdryers, as well as molded parts of your car.
6. Polyester (PES)
Polyester is a polymer formed by reacting a diol and a dicarboxylic acid.
Uses of polyesters depend on their means of production, and the polymers chains formed. The most common polyester is Polyethylene terephthalate (PET).
Used in making fibers for manufacturing clothes, making films, and packaging bottles. Terylene is one example of polyesters.
7. Polyurethane (PUR or PU)
Polyurethane is a polymer formed by joining organic units using urethane links.
The monomers used are polyol and di-isocyanate. Polyurethanes are of two types that is thermosetting and thermoplastic polyurethane.
PUR, used in making durable tires and wheels, surface coatings, synthetic fibers, foam seals, among many others.
An example of PUR is thermoplastic polyurethane (TPU).
8. Polylactic acid or polylactide (PLA)
PLA is a thermoplastic polyester obtained from renewable sources such as starch.
It is formed by reacting to its monomer, which is lactic acid. Alternatively, you can produce PLA by polymerization of cyclic lactide.
Due to its ability to biodegrade, PLA is highly used in pharmaceutical fields. An example of PLA materials is plastic cups.
How Long Does It Take for Plastic to Break Down?
A question many people ask themselves. Though you cannot say for sure the exact time, it will take for plastic to decompose.
Most of the conventional plastics are not biodegradable, or in other words, living organisms and bacteria cannot break them down. They are photodegradable.
Meaning that they only break down when exposed to rays from the sun. However, research shows that some plastics can decompose.
That is petroleum-based Oxo-biodegradable plastic and plant-based hydro-biodegradable plastic, which can take as little as a few months.
For a plastic material to decompose or break down, it can take a long time depending on the type of plastic and the extent of exposure to the sun.
For instance, if you bury plastic waste, it will not decompose due to a lack of sun rays. Even if you bury for a hundred years. PLA will decompose faster than PET materials.
From research conducted in 2009 by a university in Japan, plastic dumped in the ocean can decompose within one year due to exposure to light.
However, when plastics decompose, it breaks down to toxic substances that are harmful to the environment.
Reasons Production of Plastics Is Increasing Day by Day
Since the invention of the first plastic, production has overgrown over the years. One of the main reasons for this rapid growth is the lack of recycling.
With the high demand for various products and only less than 9% of the used plastics recycled, there is a need to produce more.
Additionally, according to Kevin Swift, plastic production increase is as a result of the rise in shale gas technologies and fracking in the United States.
This increase has intensely reduced the production cost of plastics. Therefore, many ventures in manufacturing plastic products as they can afford it.
How Much Plastic Is Recyclable?
Recycling of plastics is the course for recovering waste plastic and reprocessing it to make useful products.
Since most of the plastics cannot be decomposed or take a lot of time in the process, recycling them becomes the best option in reducing pollution.
However, not all products are recyclable due to the following factors:
Not All Plastics Can Be Recycled
For example, plastic bags, coffee cups, straws, and many others are not recyclable.
The Recycling Process Highly Depends on The Market
Without demand in the market, recycling some of these plastics then becomes useless. Therefore, dumping plastic trash in a recyclable bin will not help.
Additionally, The Government Also Plays A Crucial Role in Ensuring The Recycling of Plastics
It is regulations by the government that create chances for companies to recycle and market these products.
Therefore, if the government does not put in specific measures for recycling companies, then it becomes a challenge.
Recycling Is Expensive
Sometimes, the cost of purchasing a brand new plastic product is much cheaper, comparing to the cost of paying people to manage recyclables.
As a result, many opt to go for new items rather than recycle. Recycled plastic products also have a low value.
Recycling Plastics Lowers Its Quality
Plastics are long-chained polymers. The length of the chains is what maintains the strength and flexibility of the plastic.
Each time plastic is recycled, the chain shortens hence, lowering its quality and durability. Therefore, plastic can only undergo through recycling process once or twice to maintain its quality.
Moreover, some plastics cannot go through recycling at all because they would lose their quality and value.
With the high production of plastics, most of it ends up as trash. According to research done, more than 91% of the plastics produced do not go through the recycling process.
Alternatives for Plastics
In this modern world where plastic is now a part of us, doing away with it can be challenging.
Plastic is very convenient and easy to use. However, even with this ease, the rate at which these products are polluting the environment is alarming.
According to a survey, the leading cause of environmental pollution today is plastic products.
Recent research by the UN shows that a lot of plastics are leaking into the seas and oceans. Not only posing as a danger to the environment but also increases health risks to humankind.
However, the good news is that we have alternatives to use instead of plastics.
Here are some of the other options that will work well in place of plastics.
Bioplastic, a kind of plastic produced from plants. Production of this plastic is mainly from corn or vegetables. When you break down corn, Polylactic acid is produced and essential in making food containers.
Materials Based on Mushrooms
Mushrooms contain fibers that make packaging products. These are bio-degradable and create a sustainable and healthier package.
Milk plastic, made from a protein in milk called casein. Many manufacturing companies have adopted technology that combines clay and casein.
This process makes plastic sturdier. Products made from milk plastic easily break down and are environmentally friendly.
In conclusion, even though plastics have become a part of our day-to-day lives and have benefited us in many ways, they can be dangerous not only to humankind but to the entire environment.
However, we can correct this disaster that is rapidly growing.
Firstly, by using other alternatives other than plastics. Secondly, is by recycling these plastics. With these, we will have a clean and healthy environment.
Let us know what you think about it and leave a comment below.
Cheers to Healthy Living,
Anh-Tu and Sigmund