Should we use oil?
What are Plastics?
PLASTICS
The Plastics Industry Trade Association defines plastics as polymers made of hydrocarbons monomers and oxygen, nitrogen, sulfur, chlorine, fluorine, phosphorous, or silicon molecules. According to BBC, the carbon and hydrogen molecules used to make plastics are extracted from crude oil and natural gases throught the cracking process and then polymerized (click here to read more).
The Association of European Plastics Manufacturers explains that all plastics are polymers with different properties which can be separated in two categories: thermoplastics and thermosetting polymers. The first type can be heated and re-shaped over and over. In opposition, thermosets resist to heat and have a permanent shape.
According to PlasticsEurope.org plastic can be in the form of powders, granules, paste or liquids which are then melted to be shaped.
Plastic Polymer chain example (Polyethylene).
Plastic Granules.
How are Plastics made?
According to the American Chemistry Council, althought some plastics are naturally produced- such as rubber or latex which come from trees- most of them are synthetic.
Synthetic Plastics are made of crude oil, this natural resource is first distilled in refineries in order to separate its fractions. Through this process, the crude oil is heated and turned into gas. It then enters a tall column where the different boiling points cause its components to separate as explained by the Association of European Plastics Manufacturers.
According to BBC, these fractions of crude oil are all hydrocarbons but their molecules differ in size and structure. In order to make plastic, the Naphtha molecules are then broken down into smaller compound during the process of cracking.
The simple components optained from cracking down the distilled fractions of crude oil are then polymerized. This means that these alkene monomers are linked together to form long chains called polymers.
The British Plastics Federation explains that the structure of these polymers will then define the plastics's properties. As explain above, there are two main types of plastics, thermoplastics and thermosets.
Thermosplastics have separated molecules which move easily when heated. They have various structures- branched or linear- and lengths.This means that these plastics will be easily re-shaped when heated.
On the other hand, thermosets are three dimensional networks of tight chemical bonds. When they are first moulded, additional bonds are created which means that these plastics can neither be melted nor re-shaped.
In addtion, the Association of European Plastics Manufacturers mentions that there are several hundred types of plastics with combinations of various properties. This makes this material suitable for specific utilizations.
Crude Oil Distillation Process.
Diagram of the Cracking process of Naphtha.
Diagram of the Polymerization of Ethylene monomers into polyethylene.
Comparison of the structure of Thermoplastic and Thermosets polymers.
Crude Oil Distillation Process.
According to the Plastic Industry Trade Association (SPI),
What are Plastics used for?
USES
Plastics are used in every domain, in our daily life, we are consantly in contact with plastics. According to the Association of Plastic Manufacturers, they are mostly utilised for packagings, transportation, medical and health, sports, electronics, agriculture and construction.
As explained before, the properties of plastics are various and make this material suitable for all types of uses. They can be adapted to all needs and situations.
This Brainstorm highlights all the uses of plastic in our modern society.
DISADVANTAGES
What are the disadvantages of Plastics?
Although its properties make pastics essential in our daily life, in recent years many environmental and health organizations have tried to raise the alarm about the consequence of plastic uses. According to the History of Plastic, this material can be harmful for humans, animals and our planet.
In the past years, many associations have had concerns about the use of Bisphenol A (BPA). This clear, light, heat and shatter resistant plastic is currently used in several plastic items such as water bottles, food contained, electronic devices and sports equipement (Facts about BPA). According to One Green Planet, BPA is an endocrine disruptor which could be linked to certain types of cancer, neurogenal difficulties and defects in newborns babies. On the other hand, the European Food Safety Authority affirms that our daily exposure to BPA is far lower than the safe level and that this plastic is not a risk for consummers.
Furthermore, One Green Planet mentions that Phthalates could also represent a danger to human health. Theis chemical is usually used to make plastics more flexible and harder to break and is linked to disruption in developmental and reproductive processes. Although this has been proved to be true for laboraory animals exposed to large doses of this chemical, the effects of low levels of exposure to phthalates on human health are unknown (The Center of Disease Control and Prevention).
BPA Molecular Formula.
BPA Sources and Uses.
Phthalates Molecular Formula.
In addition to health risks, plastic use is linked to a range of environmental issues such as littering, land and water polution as explained by the Environmental Health News.
Accordingly, the History of Plastic highlights that plastic polymers take from 400 to 1000 years to decompose. Meanwhile, they keep accumulating in waterways, forests and lands which affects the food chains. Plastic littering greatly impacts the world's ecosystem as animals and fishes are often trapped in plastic garbage. In addition to plastic islands, oceans are filled with invisible plastic particules which are ingested by small organisms such as planktons. As explained by conserve-energy-future.com, this has consequences on larger animals including humans. This source also highlights the effect of plastic waste on water resources as the risk of leaking plastic garbage is high.
Indian Beach, Nariman Point, Mumbai.
Seal Trapped in Plastic Pollution.
What are the advantages of Plastics?
The various and adaptable properties of plastics represent a huge advantage over other materials as mentioned by the British Federation of Plastics. Plastic Polymers are used in several industries such as packaging, construction and transport and have economical and environmental benefits.
According to the History of Plastics, plastics are primarly used for the packaging industry. Packing companies require versatile and durable materials which have adaptable colors, forms and rigidity in order to suit their needs. In addition, Customplasticsinc.com demonstrates the light mass of plastic compared to metals which is a great advantage. This contributes to economical and environmental benefits linked to the economy of fuel for trasnportation.
The second industy which uses the most plastic in the USA are the building companies as mentioned by the History of Plastic. This source explains that the strength, resistance to corrosion, durability and toughness of plastic makes it a perfect material for contruction. Additionally, the lightness of these polymers make handy and practical valves and pipes according to PlasticsIndustry.com.
Furthermore, the use of plastics in the transport industry has helped reduce the weight of vehicles, therefore increasing their energy efficiency. Indeed, according to Futurenergia.org, the replacement of metal wing boxes by plastic fibers has helped reduce the weight of the Airbus A380 by 1.5 tons. This represents economical, environmental and social benefits as the increase in efficiency will reduce the cost of the flight and enable more individuals to afford flying.
Moreover, according to the History of Plastics the thermal and insulation properties of this material have made it very common for electronic devices. Thermosets -plastics which resist to heat and do not melt- are usually used for circuit boards, coffee makers, mixers, microwaves and hair driers. PlasticsIndustry.com, estimates that without plastics most electronics would last about half as long and would use 25 to 35% more energy.
ADVANTAGES
Common Plastic Polymers Packagings.
The use of plastics in construction pipes.
The application of plastic in trasnports (cars).
An electronic test circuit manufactured on a flexible plastic support.
ABOUT ME
As mentioned above, the overuse of plastics has been linked with several environmental and health issues. In order to cope with these problems, scientists are attempting to find alternatives to plastics.
There are two ways of reducing the impacts of plastics, first replacing them with existing solutions or materials such as glass or metal and secondly, creating and developing new industrial components which imitate the properties of plastic.
Widely used plastic items such as water bottles and plastic bags can individually replaced by existing objects or materials.
According to BanTheBottle.net, every year in USA about 50 billion plastic water bottles are used but only 23% are recycled. Instead, ecofriend.com recommend to use glass or stainless steel bottles which are reusable and BPA free. These alternatives are more durable but also heavier and inconvenient, also while steel is shatter resistant, glass breaks easily. Therefore these alternatives can be used at home but are not easy to carry around.
Plastic Bags also represent a significant issue as each year between 500 billion to 1 trillion plastic bags are consumed worldwide and less than 5% are recycled, according to the Environmental Protection Agency. The first alternative to plastic bags is single-use paper bags which seem in appearance greener. In facts, the Guardian explains that making paper bags uses 4 times as much as energy, creates 70% more air pollution and 50 times more water pollution than plastic bags. The second alternative to plastic bags are reusable cotton or jute bags but these also have underestimated environmental consequences. Indeed, a report from UK's Environment Agency showed that a cotton bag would have to be used 171 times to match the carbon dioxide emission of a single-use plastic bag. It also explains that massive amounts of water, chemical pesticides and energy are required to produce and transport woven bags.
In addition to these alternatives, new materials such as PHB Composites, PLA and liquid wood have been developed in order to replace traditional plastic polymers.
According to Ecofriend.com, PHB Biocomposites could be a possible substitute for packings and biomedical and agricultural uses of plastics. This modified version of PHH -polyhydroxybutyrate- is produced by the natural fermentation of various bacterias. ScienceDirect.com mentions it has similar properties to plastic but is more sustainable and environmentally friendly. This material also has lower production cost, requires less energy, absorbs CO2, returns oxygen and emits very little toxic fumes during combustion. Although PHB Biocomposites have several advantages over plastics it is less durable, strong and resistant.
Polylactic Acid, also known as PLA, is another alternative to plastic. According to Bionomicfuel.com, it is made from fermented starch and could be used to make containers, packagings and consumer products. This material has several economical and environmental advantages over traditional plastics as mentioned by ScientificAmerican.com. PLA is carbon neutral, renewable and economically advantaging as it is comes from cheap carbon-absorbing plants. Moreover, it emits neither fumes nor greenhouse gases when incinerated and requires 65% less energy to be produced than plastics.
Additionally, this material is free from toxins such as BPA and Phthalates but is often based on genetically modified corn which effects are unknown as explained by EcoFriend.com. Also, although reputed for being biodegradable, this material would actually take from 100 to 1000 years to decompose in the environment according to ScientificAmerican.com. Furthermore, PLA can not be mixed with traditional plastics in recycling facilities, it needs to be separated and sent to composing infrastructures which are quite rare- only 113 in U.S.
Liquid Wood is another type of biopolymer which could be a more viable alternative to plastics. According to NBC news, this material is made by mixing lignin - a byproduct of paper mills- with water. The mixture is then exposed to high pressures and temperatures to create a moldable composite material. According to EcoFriend.com, this substitute has the same properties to plastic -durable and strong- but is also biodegradable, renewable and non-toxic. Liquid Wood bypolymer has been used to make items such as toys or golf tees.
ALTERNATIVES
Can Plastics be replaced?
Plastic Pollution due to the accumulation of plastic bottles in waterways.
Alternatives to Plastic Bottles:
Stainless Steel or glass bottles.
Plastic Pollution due to the accumulation of plastic bags in oceans.
Alternatives to Plastic Bags: Paper or reusable cotton bags.
Alternative to Plastic: PHB Biocomposites used in the packaging, biomedical and agricultural industry.
Alternative to Plastic: Polylactic Acid (PLA) used for comtainers, packagings and consumer products.
Alternative to Plastic: Liquid wood typically used to make toys, and golf tees, has also been used to construct the Toyota MOB.