Education

Understanding Plastic Composition, Types, Facts, and Uses

Have you ever thought about Properties of Plastic and their chemical composition or how it’s made? This article will explain the nature of plastic and how it’s formed with in-depth information and an explanation of the type.

Plastic Definition and Composition

Plastic can be described as any organic, semi-synthetic or synthetic polymer. Even though different elements may be present in plastics, they always comprise hydrogen and carbon. Although plastics can be made out of any organic polymer, most industrial plastic is made of petroleum-based chemicals. 

Thermosetting Polymers are thermoset Polymers and are two kinds of plastic. The term “plastic” refers to the characteristic of plasticity, which is the ability to bend without breaking.

The polymer used in the production of plastic is often blended with other additives, such as colours, plasticisers, stabilisers, fillers, and reinforcements. These additives impact the chemical structure, properties of plastic, and cost.

Thermosets and Thermoplastics

Thermosetting polymers, also referred to as thermosets, solidify to the shape of a permanent. They are amorphous and are believed to be amorphous and have infinite molecular weight. Thermoplastics, they can be heated and remoulded repeatedly. 

Certain thermoplastics are amorphous, and others have a crystal structure. Thermoplastics usually have a molecular mass of 10,000 and 500 000 AMU (atomic mass unit).

Plastics are usually identified by abbreviations for their chemical formulas.

  • PET, or PETE
  • Polyvinyl chloride: PVC
  • HDPE is high-density polyethylene
  • Polypropylene: PP
  • Low-density polyethylene LDPE
  • Polystyrene: PS

Properties of Plastics

Plastics’ properties are based on the composition and chemical properties of subunits, their arrangement, and the method of processing.

All plastics are polymers; however, some polymers may not be. Plastic polymers are made up of chains of linked subunits, also known as monomers. If monomers of identical composition are joined, they form homopolymers. Different monomers connect to create copolymers. 

Copolymers and homopolymers could be straight chains or branching chains.

Other characteristics of plastics are:

  • Plastics are typically composed of solids. They could be amorphous as well as crystalline solids—Semi-crystalline solids (crystallites).
  • Plastics are typically poor conductors of electricity and heat. They are mostly insulators that have strong dielectric strength.
  • Glassy polymers are typically rigid (e.g. polystyrene). However, small sheets made of them may be made into films (e.g. polyethylene).
  • Most plastics show the phenomenon of elongation when stretched, and it is not recovered when the stress is removed. This is known as “creep.”
  • Plastics are usually robust and have a low decay rate.

Types of Plastic

Plastic is an important component of many things such as water bottles, combs and even beverage containers. Understanding the distinction, 

in addition to the SPI codes, can aid you in making more informed choices about recycling.

The seven plastic types comprise:

  • Polyethylene Terephthalate (PETE or PET)
  • Low-Density Polyethylene (LDPE)
  • Polypropylene (PP)
  • High-Density Polyethylene (HDPE)
  • Polyvinyl Chloride (PVC)
  • Polystyrene or Styrofoam (PS)
  • Plastics of various kinds (includes polycarbonate, also known as polylactide, polycarbonate, acrylonitrile butadiene, as well as fibreglass and nylon)

The complete list of plastics contains:

1 – Polyethylene Terephthalate (PETE or PET)

It was first introduced through J. Rex Whinfield and James T. Dickson in 1940; plastic was among the most frequently utilised globally. Incredibly, it took another 30 years until it was being used for crystal-clear bottles for drinks like those made through Coca-Cola and Pepsi.

PETE plastics comprise 96 per cent of the plastic containers and bottles sold in the United States, yet only 25% of these items are recycled. By taking care and making sure that you recycle plastics that are code 1, you’re helping ensure the environment is kept cleaner and less pollution in landfills!

2 – High-Density Polyethylene (HDPE)

In 1953 Karl Ziegler and Erhard Holzkamp employed catalysts as well as low-pressure to produce high-density polyethylene. It was initially used to construct pipes for the storm drainage system and drains and culverts. Nowadays, plastic is used in many different products.

HDPE is the most frequently recycled plastic since it does not break when exposed to extreme cold or heat. As per the EPA, 12 per cent of HDPE produced are recycled each year. This is a tiny footprint in the carbon footprint.

3 – Polyvinyl Chloride (PVC)

PVC is among the oldest synthetic substances used in industrial production. It was discovered by accident two times: once around 1838 by French scientist Henri Victor Regnault and again in 1872 by German scientist Eugen Baumann. In both instances, the scientists found it in flasks of vinyl chloride that had been exposed to light.

PVC is among the least recycled materials; generally, less than one per cent of PVC is recyclable every year. It is often referred to as “poison plastic” because it contains a wide range of toxic substances and is dangerous to our health as well as the environment.

4 – Low-Density Polyethylene (LDPE)

LDPE was the first form of polyethylene made and is, therefore, the original material. It is lighter than HDPE, which is the reason it’s considered to be a separate substance to be recycled.

Containers and packaging made from LDPE comprise approximately 56% of all plastic waste, with 75 per cent of which homes generate. Many recycling programs are developed to deal with these items. This means that less LDPE will end in landfills and will negatively impact the environmental quality!

5 – Polypropylene (PP)

  1. Paul Hogan and Robert L. Banks of Phillips Petroleum Company discovered polypropylene in 1951. In the beginning, they were just trying to transform propylene into gasoline, but they instead discovered a brand new catalytic process to make plastic.

Just 3 per cent of polypropylene items are recycled within the US. However, it is interesting to note that 325 million pounds of non-bottle-based plastics were collected from recycling over the course of one year. This means that much of the plastic is made, but only a tiny fraction is recycled.

6 – Polystyrene or Styrofoam (PS)

In 1839, German pharmacy technician Eduard Simon discovered polystyrene by accident in the course of making medications. Simon isolated a compound made from natural resin but did not know what he’d found. It required German scientist Hermann Staudinger to research this polymer further and to expand its applications.

Since it is lightweight and easy to mould into plastic, it easily breaks, making it more dangerous in the natural environment. The world’s beaches have numerous different types of plastics that are littered with bits of polystyrene that threaten the life and health of marine creatures. Polystyrene makes up about 35 per cent of US garbage materials.

7 – Miscellaneous Plastics

The other plastics are polycarbonate, polylactide, acrylonitrile butadiene and fibreglass. The last three are nylon and polycarbonate. Naturally, there are numerous different types of plastics that are classified as miscellaneous by recycling programs.

A lot of BPA products fall under this category, meaning it is best to stay clear of BPA, particularly for food items. It’s difficult to break these plastics down after being made and exposed to extremely high temperatures. This makes them almost impossible to reuse.

These were all plastic types you should know about.

Let’s conclude by knowing some Interesting Plastic Facts

Additional information on plastics:

  • The first fully synthetic plastic was completely synthetic Bakelite created in 1907 by Leo Békeland. He also coined the term “plastics.”
  • The term “plastic” comes from the Greek word Plastikos meaning it can be moulded or shaped.
  • About a third of the plastic made is used for packaging. A third of it is used for pipe and siding.
  • Pure plastics are typically insoluble in water and are nontoxic. However, some of the chemicals in plastics are harmful and could be released into the surrounding environment. 
  • Examples of harmful additives are phthalates. Non Toxic polymers can also degrade into chemical compounds when heated.

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