Composition and Types of Plastics and Fibres

Plastics are a broad category of synthetic and semi-synthetic materials containing polymers as a primary constituent. Because of their fluidity, plastics may be moulded, extruded, or pressed from solid products of different forms. This versatility and various other features, including lightweight, robust, flexible, and economical to create, have resulted in widespread application. Between 1950 and 2017, an estimated 9.2 billion tons of plastic were produced. Since 2004, more than half of this material has been manufactured. This article will discuss the types of plastic and their composition, usage, and importance, along with their chemical formulation.

What is plastic?

Plastic is a polymeric substance that can be moulded or formed, often by pressure and heat. Plasticity, when combined with other specific features like low electrical conductivity, transparency, low density, and toughness, enables plastics to be produced in a wide range of items. These include durable and lightweight polyethylene terephthalate or PET drinking bottles, flexible garden hoses manufactured of polyvinyl chloride known as PVC, insulation food containers built of foamed polystyrene, and shatter-resistant windows constructed of polymethyl methacrylate.

Organic polymers are found in the majority of plastics. A significant number of these polymers are made up of carbon atom chains with or without the addition of nitrogen, oxygen, or sulphur atoms. These chains are composed of many repeating units composed of monomers. Millions of repeating units make up each polymer chain. The foundation is the network component that connects a high number of repetition units and is on the critical pathway. To tailor the characteristics of plastic, distinct molecular groups known as side chains are hung from this backbone; these are typically hung from monomers first before monomers themselves are brought together to create the polymer chain. The design of these side groups determines the polymer’s characteristics.

What are the different types of plastic?

So how many types of plastic are there? Not that all plastic is created equal. In reality, not just plastic has been found in a wide range of forms and colours, but it can also be found in various types. Each one is unique and serves a particular purpose. Some forms of plastic, for example, are reusable while others are not due to the chemicals they possess; some may be recycled while others must be thrown off differently.

Types of plastics are :-

• PET: Polyethylene terephthalate, or PET, is used to make plastics of group one. It is ranked first because of its vast utility. Because of its excellent capacity to keep oxygen from entering and damaging the goods within is typically used primarily for food and beverage packaging.

• PVC: Polyvinyl chloride is the third most common synthetic plastic polymer globally. It is classified into two types: rigid and flexible. PVC is widely utilised in the construction sector in its rigid form to manufacture window and door profiles and pipelines. However, it may be made soft and versatile by combining it with other substances and applying it to piping, wiring, copper cabling insulation, and flooring.

• HDPE: High-Density Polyethylene or HDPE is a very durable resin that is used in agricultural tubing, shopping bags, recycling bins, milk jugs, as well as playground equipment, caps, and shampoo bottles, among other things. It is significantly more rigid and thicker than PET since it is formed of long unbranched polymer chains. It is also relatively complex and impact-resistant, and it can withstand temperatures up to 120 °C without deterioration.

• LDPE: In contrast to HDPE, LDPE is distinguished by low-density molecules, resulting in a lighter and more flexible resin. It has the basic structure of any plastic, making it simple and inexpensive to create. However, it is not typically recycled through curbside programs because it is used in plastic bags, 6 rings, different containers, dispensing bottles, and, most notably, plastic wraps.

• PS: The sixth form of plastic on that list is polystyrene, which can be hard or foamed. Because it is a low-cost resin per unit of weight and simple to manufacture, it may be found in various applications, including insulation, egg cartons,  packaging materials, drinking cups, and disposable tableware.

• PP: Polypropylene is the 2nd commonly manufactured commodity plastic, and its market is expected to expand more in the coming years. It is a complex and robust material that can tolerate extreme temperatures and is used in Tupperware, automobile components, thermal jackets, yoghurt containers, or even disposable diapers.

• Others: If plastic could still not be recognized in the six categories listed above, it will be classified as group number 7. Polycarbonates or PC are the most well-known polymers in this class, and they are used to make solid and durable items. For example, polycarbonates are extensively utilised in manufacturing lenses for glasses, sports goggles, and safety goggles for eye protection. They can, however, be discovered on mobile phones or, more commonly, compact disc CDs.

Conclusion

Plastic uses may differ in developing countries; 42 per cent of India’s usage is utilised in packaging. In addition, plastic is used to make polymer transplants and other medical equipment. Every year, around 50 kilograms of plastic are created per person globally, with output increasing every ten years. However, Toxic chemicals seep out of plastic and thus are detected in practically everyone’s blood and tissue. Exposure to them has been related to malignancies, birth abnormalities, weakened immune system, endocrine disruption, and other health problems.