Chemistry of Plastics

What is Plastic?

The Greek term "plastikos", which indicates it may be molded or formed, is where the word "plastic" originates. Any synthetic or semi-synthetic organic polymer is considered plastic. In other words, while additional elements may be present, carbon and hydrogen are always present in plastics. While all polymers are not plastic, all plastics are polymers. Chains of connected monomer subunits make up plastic polymers. A homopolymer is created when two identical monomers are combined. To create copolymers, several monomers join together. Both homopolymers and copolymers can have branched or straight chains. While almost any organic polymer can be used to make plastic, petrochemicals are the primary source of industrial plastic. Thermoplastics and thermosetting polymers are the two forms of plastic. The term "plastic" refers to a substance's capacity for deformation without breaking. Almost always, colorants, plasticizers, stabilizers, fillers, and reinforcements are added to the polymer used to produce plastic. The chemical make-up, chemical characteristics, mechanical characteristics, and price of plastic are all impacted by these additives. 

Leo Baekeland created Bakelite in 1907, which was the first fully synthetic plastic. The term "plastics" was also his invention. In recent decades, the manufacture of plastics has increased steadily worldwide. Among other things, plastics enable us to use electronics, insulate buildings, preserve food, and increase the fuel efficiency of automobiles. However, the vast amount of plastics consumed in our society has a negative impact on the environment and wildlife, creates large amounts of garbage, and has a significant carbon footprint associated with production.

Well, Chemical compounds can be turned into plastics. Isn't it like magic? Obviously not.  The very real union of engineering, energy, and raw materials—all brought together through chemistry—leads to the creation of plastics.  Although plastics can be highly sophisticated materials, comprehending their fundamental structure is simple. Here's a quick overview of how chemists enable modern polymers. 

Chemistry of Plastics: Production of Plastic

Chemists start with a variety of elements (atoms including carbon, hydrogen, oxygen, and other atoms) sourced from natural resources to create today's plastics. Do you still have in mind that beautiful periodic table of chemical elements that contains the components of everything on earth? That is the list of ingredients of plastics.

To create molecules, which are only two or more atoms joined together by chemical bonds, chemists mix different atoms. These molecules are typically referred to as monomers for creating plastics. The process of joining these monomers together to form a chain or network is known as polymerization. And the finished products are known as polymers.

Thermoplastics and Thermosets: The Science of Plastics

The polymer is known as a thermoplastic if the monomers combine together and are lined up in a chain (like a string of pearls). This plastic acts something like an ice cube: it repeatedly melts when heated and solidifies when cooled. A thermoplastic is an example, such as polypropylene (the material used frequently in butter tubs).

The polymer is referred to as a thermoset if the monomers form a three-dimensional network. This plastic has similar behavior to an egg in that it cannot go back to its goopy, liquid condition after it has "cured" and set. An illustration of a thermoset is an epoxy from the hardware store that cures and hardens after application. Thermosets can be particularly durable since they are made of a three-dimensional network of monomers. For instance, thermoset plastics are used to create the tires on your car (often called synthetic rubber). Thermoplastics are also durable, although they are frequently employed in less demanding applications, such as lightweight soft drink bottles that are not exposed to extreme heat and friction like tires.

Constant Evolution of Chemistry of Plastics: 

Chemists (along with other intelligent individuals) have developed numerous methods over time to mix components to create new polymers... and even to combine polymers. The molecules can be fashioned with varied qualities depending on what we need: sticky or slippery or lightweight or soft or hard or foamy or stretchy or … well, you get the point. That is why plastics are utilized in so many practical everyday items, such as spatulas, automobile bumpers, medical implants, and garment textiles.

And this is just the beginning; chemists are continually coming up with brand-new, inventive polymers that will help make things like airplanes lighter, hearts beat more powerfully, food keeps fresher, homes more energy-efficient, and other things.

Examples of Plastics 

The acronyms for the chemical formulas of plastics frequently used are :

• PP: Polypropylene
• PS: Polystyrene
• HDPE, or high-density polyethylene
• LDPE, or low-density polyethylene
• PET or PETE stands for polyethylene terephthalate.
• PVC, or polyvinyl chloride

Use of Plastics:

1. Materials made of different elements, including carbon, hydrogen, oxygen, nitrogen, chlorine, and sulfur, are referred to as "plastics."
2. Modern technology employed in the space program, bulletproof jackets, and even prosthetic limbs heavily rely on plastic items and materials.
3. By minimizing waste, cutting greenhouse gas emissions, and preserving energy at home, at work, and on the road, plastics assist us in protecting the environment. Plastic packaging allows us to ship more products with less packing material, extending the shelf life of fresh foods and beverages and minimizing food and packaging waste.
4. Plastics lighten vehicles, which can significantly impact pollutants and fuel economy. Additionally, lightweight plastics can significantly increase a car's miles per gallon, which can save drivers money at the pump.
5. Strong, lightweight plastics help us do more with less, which improves our quality of life while also promoting sustainability in a variety of ways.
6. In addition to lowering heating and cooling costs, plastic insulation, sealants, and other building materials are greatly improving the energy efficiency of our homes. 

Most pure polymers are non-toxic and insoluble in water. But many of the compounds used in plastics are hazardous and could contaminate the environment. Phthalates are a couple of harmful additive examples. When heated, non-toxic polymers may also break down into chemicals. Growing public knowledge of the pervasiveness of plastic pollution has recently influenced public opinion and prepared the path for more aggressive regulatory intervention in this area. The OECD Global Plastics Outlook publications aim to assist and provide information for these initiatives.