1903, when first plastic was being synthesized in a laboratory, nobody expected that the material once created will last for at least next 10-50 years. (All thanks to Mr Baekeland!)
We have a millennial-old history of making plastic-like materials. It is the same set of properties, such as strength, flexibility, etc., we see in most of the plastics today, that came up as an urge to develop such materials.
Back in time, these so-called plastic-like materials were made using blood proteins, eggshells, shellac, etc. Over time, we moved on to making chemically modified natural versions of plastic such as nitrocellulose, collagen, natural rubber, etc.
Being organic in nature turned out to be the biggest limitation for these materials, as they would undergo decomposition or breakdown by microorganisms in no time. This, of course, would be a great thing if such materials were in use today, but it wasn’t the kind of material needed at that time.
After using the plastic-like materials for centuries, mankind embarked on a quest of inventing a material that is chemically inert and can withstand the external factors such as heat, moisture, and microbial degradation of course, well without compromising with the properties such as flexibility, strength, etc.
Deep down below the surface of the earth, the dead remains of plants and animals were already taking the shape of different states of matter, viz., solid, liquid and gas, under extreme heat and pressure conditions.
The three forms were collectively called as fossil fuels, as they were nothing but the dead remains of plants and animals, that likely includes dinosaurs as well, decomposed over a period of millions of years.
1859 saw the day in history when fossil fuel was successfully drilled up to the surface for the first time. However, the fuel had a lot of impurities in it. Hence, it was called crude oil.
Image taken from current kids
An additional step, after withdrawing the oil from the ground, was necessitated that would remove the unwanted materials from the oil, and make it suitable for use in machines. This is where refineries came into existence. The purpose of the refinery is to purify the crude oil and convert it into fractions by a process called fractional distillation.
Petrol, diesel, Kerosene, etc,. are few examples of the fractions formed from the fractional distillation of crude oil. But the fraction we are most concerned about is Naphtha!
Naphtha is a product of the fractional distillation of crude oil which is used as a precursor for synthesizing the raw materials for plastics. Yes, you read it right! All that plastics you have around yourself, and maybe inside or over the device, you are using now to read this article is made from petroleum that was once buried deep into the Earth. Should we worry about the ever-increasing production of plastics now?
From Petroleum to Plastic!
To synthesize plastic, Naphtha is subjected to thermal decomposition and separation by making use of the difference in the boiling point to form ethylene and propylene, which are the raw materials for plastics.
Most of the plastics are high-molecular compounds. To create a high-molecular compound, it is necessary to produce low-molecular compounds first, and then bond them together. This reaction is known as polymerization.
The low-molecular weight compounds are termed as Monomers, and the high-molecular-weight, or simply high-molecular compounds are called as Polymers. Here, the word ‘mono’ means ‘single’ and ‘poly’ means ‘multiple.’
The formation of polymers from monomers uses heat, light, and additives such as enzymes (polymerization initiators). In this way, ethylene and propylene, which are monomers, are polymerized or converted into long-chain polymers, namely ‘Polyethylene’, (popularly known as Polythene) and polypropylene, respectively.
Image taken from slideplayer.com
Okay! It’s time to wrap up the story. The idea was not to detail how plastic is made but to emphasize how we are putting one of our precious natural reserves, the fossil fuels, at risk only to create something that will eventually end up in the landfill, or may be found drifting along the ocean currents or clogging the rivers.
It’s time we should Act! It’s time we must Rethink, Reduce, and Recycle plastics as much as possible!