Plastics are Organic synthetic materials.
Chemistry of Plastics
The polymerization process. This way the monomers are joined together in a sequence to grow in a specific way. The monomer word plastic is derived from the Greek word meanings ''to grow''. Hence it is synthesized by there are joined together in straight chain or branched chain. It decides the nature of plastic that it would be thermosetting or thermoplastics.
The raw materials are of organic in nature i.e natural gas, oils,or plants. By refining the raw materials ethene or propene gas are obtained that are basics raw materials and when the cracking of ethene and propene are obtained this ethylene or propylene is basically, used as monomers in the polymerization of plastic but the derivatives of ethylene or propylene are also used. These derivatives are PVC, nylon, styrene, polyamide, poly-acetate etc.
Types of plastics
1. Thermoplastics:
A thermoplastics is one that can be softened repeatedly when heated and hardened when cooled with a little change in properties. These are less rigid than thermosets. These are easily molded. So can extruder into films, fibers, and packaging.
Examples: PVC pipes, plastic toys, polyethylene PE, polypropylene PP, etc
2. Thermosetting polymer.
The polymers which become hard on heating and cannot be softened again are called thermosetting polymers. A thermosetting polymer, on heating, decomposes instead of melting. Thermosets can be used for auto parts, aircraft parts, and tires.
Examples: synthetic varnish, epoxy resins, polyurethanes, and phenolic resins.
Manufacturing of plastic
The following steps are for the manufacturing i.e.
1. Firstly refining of the raw materials i.e natural gas, oils, plants, etc. is done. This way propane and ethane are obtained.
2. cracking of propane and ethane gives the monomer of ethylene and propylene
3. In step 3 polymer fluff is made by adding a catalyst it looks like laundry detergent.
4. Then the polymer is added to the extruder where it melts and fed into a pipe.
5. On cooling melted plastic forms a long tube as it cools.
6. The tube is cut into small pallets.
7. pallets are shifted to factories to be melted and molded into water bottles, food packing, auto parts, medical devices, and much more.
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