Table of Contents
What are Polymers?
Polymers are long chains of repeating molecules. The molecules can be made of a variety of different elements, but most polymers are made of carbon and hydrogen.
Types of Polymers
There are three types of polymers – natural, synthetic and semi-synthetic.
- Natural polymers are made from natural materials like plant and animal products. Examples include cellulose (from plants) and collagen (from animals).
- Synthetic polymers are made from petrochemicals, like oil and natural gas. These polymers are usually very strong and durable. Examples include polyethylene (used in plastic bags) and polypropylene (used in bottle caps).
- Semi-synthetic polymers are made from a combination of natural and synthetic materials. An example is rayon, which is made from cellulose and synthetic chemicals.
Classification of Polymers
Polymers are classified as thermoplastic or thermoset. Thermoplastics are materials that can be repeatedly softened by heat and then hardened again. They are typically used in engineering applications where a component needs to be repeatedly melted and formed. Thermoset plastics are materials that are hardened by heat and cannot be softened again. They are typically used in applications where a component needs to be permanently formed, such as an electrical connector.
Synthetic Polymers
a. Polyethylene
- Polyethylene a synthetic polymer made from the monomer ethylene. It is a thermoplastic, meaning it can melted and molded multiple times. It is the most common type of plastic and is used to make bottles, bags, and food packaging.
- Polyethylene is a strong and lightweight material that is resistant to chemical corrosion. It is also non-toxic and can recycled. However, it is not biodegradable and can take centuries to decompose in a landfill.
b. Polypropylene
- Polypropylene a synthetic polymer made from the monomer propylene. It is a thermoplastic, meaning it can melted and molded multiple times. It used to make bottles, toys, and automotive parts.
- Polypropylene is a strong and lightweight material that is resistant to chemical corrosion. It is also non-toxic and can recycled. However, it is not biodegradable and can take centuries to decompose in a landfill.
What are Synthetic Polymers?
Synthetic polymers are man-made materials that composed of long, repeating chains of molecules called monomers. However synthetic polymers used in a variety of applications, including packaging, textiles, and construction materials.
Types of Synthetic Polymers
There are many types of synthetic polymers, but some of the most common are plastics, elastomers, and fibers.
- Plastics are a type of synthetic polymer that typically used to make products that are durable, lightweight, and easy to mold. Examples of products made from plastics include water bottles, Tupperware, and car parts.
- Elastomers are a type of synthetic polymer that typically used to make products that are stretchy and flexible. Examples of products made from elastomers include rubber bands, swim caps, and also bike tires.
- Fibers a type of synthetic polymer that are typically used to make products that are strong and lightweight. Examples of products made from fibers include tents, backpacks, and clothing.
Nylon
Nylon is a synthetic fiber that is strong and durable. It often used in clothing, such as tents, backpacks, and other outdoor gear.
Low-Density Polyethylene
Low-density polyethylene (LDPE) a type of polyethylene characterized by a low molecular weight and a density of less than 0.94 g/cm3. LDPE sometimes called “ultra-low-density polyethylene” (ULDPE). LDPE is generally translucent and flexible. It used in applications such as packaging and labeling, where a flexible material needed.
Polyvinyl Chloride
Polyvinyl chloride a synthetic polymer made from the monomers vinyl chloride and ethylene. PVC is a white, odorless, and non-toxic material. It used to make pipes, tubing, and other plumbing materials. PVC also used to make vinyl siding, flooring, and other types of construction materials.
Polypropylene
Polypropylene a polymer made of propylene monomers. It is a thermoplastic, meaning it can melted and molded into new shapes. It used to make a variety of products, including food packaging, car parts, and also medical supplies.
Examples of Major Synthetic Polymers
- Polyethylene (PE)
- Polypropylene (PP)
- Polystyrene (PS)
- Polyvinyl chloride (PVC)
- Polyethylene terephthalate (PET)
- Polyurethane (PU)
Uses of Synthetic Polymers
There are many uses for synthetic polymers. Some of the most common uses listed below.
- Plastics are the most common type of polymer. They used in many products, including food packaging, bottles, and aslo toys.
- Rubber is a synthetic polymer that used in products such as tires, hoses, and seals.
- Polyester is a synthetic polymer that used in products such as clothing, upholstery, and carpets.
- Polypropylene is a synthetic polymer that used in products such as ropes, sacks, and bottles.
- Polyethylene is a synthetic polymer that used in products such as food packaging, bottles, and bags.
Categories of Synthetic Polymers
Polymers synthetic materials made from long chains of repeating chemical units.
There are six main categories of synthetic polymers:
- Thermoplastics: These polymers can melted and reshaped when heated, and they usually return to their original shape when cooled. Examples include polyethylene, polypropylene, and polystyrene.
- Thermosets: These polymers can melted and reshaped, but they will not return to their original shape once cooled. Examples include epoxy, phenolic, and silicone.
- Elastomers: These polymers are stretchy and can pulled back to their original shape after stretched. Examples include rubber, neoprene, and silicone.
- Fibers: These polymers thin, strong, and flexible. They often used to make textiles and clothing. Examples include nylon, polyester, and also rayon.
- Plastics: These polymers used to make products such as bottles, cups, and packaging. They are strong, durable, and lightweight. Examples include polypropylene, polyethylene, and polystyrene.
- Adhesives: These polymers used to stick things together. Examples include epoxy, silicone, and also rubber.
Thermosets
Thermosets are polymers that once they cured, they cannot melted again. Therefore they made by reacting a monomer with a cross-linking agent.
Thermoplastics
Thermoplastics are plastics that melted and poured into a mold to form a desired shape. The plastic then cooled and solidified. Thermoplastics can reheated and remolded multiple times. Some common thermoplastics polyethylene, polypropylene, and polystyrene.
Elastomers
Elastomers are polymers that have the ability to stretch and return to their original shape. They made of long chains of molecules that cross-linked. This makes them more resistant to stretching and tearing than other types of polymers.
Elastomers often used in products that need to be stretchy, such as rubber bands, balloons, and swim caps. They can also used in products that need to be resistant to impact, such as rubber bumpers and shock absorbers.
Synthetic Fibres
Synthetic fibres are man-made and are made from petrochemicals. They divided into two main categories:
1. Polyester
Polyester is the most common type of synthetic fibre. It made from ethylene glycol and terephthalic acid, which both derived from oil. Polyester is strong, durable, and resistant to wrinkles and also resistant to shrinking. It often used to make clothing, upholstery, and carpets.
2. Nylon
Nylon is another common type of synthetic fibre. It made from polyamide, which a polymer made from petroleum. Nylon strong and durable and can used to make clothing, carpets, and ropes.
Advantages and Disadvantages of Synthetic Fibres
The advantages of synthetic fibres are that they are strong, lightweight, and resistant to moisture. They also tend to be less expensive than natural fibres. The disadvantages of synthetic fibres are that they may not be as breathable as natural fibres, and they can be more difficult to dye than natural fibres.
Disadvantages of Synthetic Polymers
The disadvantages of synthetic polymers are that they can be toxic, they can create pollution, and also they can be non-biodegradable.