Polymers and Monomers

Plastics are actually polymers, constructed from lots of repeating units of these monomers. It’s like building with blocks, but each type of plastic has its own unique set of monomers, like blocks with different shapes and sizes. Take Polyethylene (PE) for example – it’s like the king of plastics. PE has really strong carbon-carbon bonds, which make it tough and flexible. The simple molecule, ethylene, is its “pearl. “Then there’s Polyvinyl chloride (PVC) -This plastic is versatile because it adds a chlorine atom to each carbon chain. That makes it stronger and more rigid, perfect for things like pipes and construction. Lastly, think of Polystyrene (PS) – the one you find in foam cups. Its “pearl” is a benzene ring, which gives it good insulation properties but also makes it a bit brittle. So, in a nutshell, polymers and monomers are like the building blocks that create different types of plastics with unique characteristics.

Plastic is defined as a material that contains an essential ingredient an organic substance of large molecular weight. It is also defined as polymers of long carbon chains.

Types of Plastics

Depending on physical properties, plastics are divided into two types: Thermoplastic and thermosetting.

Thermoplastic: Plastics that can be deformed easily upon heating and can be bent easily. Linear polymers and a combination of linear and cross-linked polymers come under thermoplastics. Example: PVC, nylon, polythene, etc.

Thermosetting: Plastics that cannot be softened again by heating once they are moulded. Heavily cross-linked polymers come under the category of thermosetting plastics. Example: Bakelite, melamine, etc. Bakelite is used for making electrical switches whereas melamine is used for floor tiles

Properties of Plastic

• Strong and ductile.
• Poor conductors of heat and electricity.
• Easily moulded into different shapes and size.
• Resist corrosion and are resistant to many chemicals.

Advantages of Plastics 

• Plastics have numerous advantages and uses.
• Few of them are stated below –Its production cost is low.
• It can be easily moulded into various shapes.
• It is lightweight.
• It is resistant to corrosion.
• It can be translucent, transparent, and opaque as well.
• It is a poor conductor of heat and electricity.
• It can be used to make roads, utensils, wires, pipes etc
• It is used in construction of buildings as well

Disadvantages of Plastics

• Plastics manufacturing also involves the addition of potentially hazardous compounds like stabilisers or colourants.
• Many of these have not been subjected to environmental risk assessments, therefore their influence on human health and the environment is unknown at this time
• Phthalates, which are used in the production of PVC, are one such example. PVC has been used in toys for young children in the past, and there have been concerns that when these toys are chewed, phthalates may be produced
• The impacts of phthalates on the environment are currently being assessed for risk. The disposal of plastics products also has a significant influence on the environment.
• Most plastics are non-biodegradable, and once landfilled, they might take a long time to decompose. With an increasing number of plastic products, especially plastic packaging, being discarded quickly after purchase, the amount of landfill space required by plastic waste is becoming a major concern
• Cheap production and easy availability make plastic very useful, but it has many shortfalls and its harmful effects are a cause of huge concern for us to save our earth and ourselves.
• Its few disadvantages are listed below –Natural decomposition of plastic can last from 400-1000 years and few types of plastics are non-degradable as well.Plastic materials clog waterways, oceans, seas, lakes etc. 1 in 3 species of marine mammals have been found entangled in marine litter. 
• Many animals eat plastic materials and die. Over 90% of all seabirds have plastic pieces in their stomachs. 
• Plastic is widely used in packaging. Eating food out of plastic containers may cause cancer
• Both creation and recycling of plastic produce toxic gases and residues which causes air and water and land pollution. 
• Few additives such as phthalates etc. which are added in plastics to prevent its structure may cause serious hormonal imbalance in males and females. 
• Plastic causes many fire hazards. Its cost of recycling is also very high. 

Disadvantages of plastic bags are well known; this is the reason why use of plastic bags have been restricted in most of the countries in the world.

Highlights of the Plastic Waste Management (Amendment) Rules 2024

• It defines biodegradable plastics as not only capable of degradation by biological processes in specific environments such as soil, landfill, but also as materials that do not leave any microplastics.
• However, the caveat about microplastics in the updated rules does not specify – Which chemical tests can be used to establish the absence of microplastics, or
• To what extent microplastics must be reduced in a sample in order to consider them eliminated.
• The amendment provides that the manufacture of carry bags and commodities shall be permitted to be made from compostable plastics or biodegradable plastics.
• This is subject to mandatory marking and labelling laid down under the rules and the regulations of the Food Safety and Standards Authority of India (FSSAI) for food contact applications.
• The rules require the manufacturers of compostable plastic or biodegradable plastic carry bags or commodities to obtain a certificate from the CPCB before marketing or selling.
• Every manufacturer of commodities made from plastic shall -Ensure processing of the pre-consumer plastic waste generated in the form of reject or discard material at the stage of manufacturing and report to the State Pollution Control Board or Pollution Control Committee concerned.