[Chemistry Class Notes] on Uses of Polymers Pdf for Exam

The simplest way to understand the term polymer is a beneficial chemical made of many repeating units. A polymer can be a 3-dimensional (3D) network Imagine of a repeating unit joined together left and right, back and front, up and down or it is a 2-dimensional (2D) network Imagine of the repeating units linked together right, left, down, and up in a sheet or a 1-dimensional (1D) network Imagine of a repeating unit-linked right and left in a chain. Each unit that repeats is the “-Mer” or has a fundamental unit with “polymer” meaning multiple repeating units. The unit which is repeating is often made of hydrogen and carbon and sometimes nitrogen, oxygen, fluorine, sulfur, chlorine, silicon, and phosphorus. This forms a chain, many links or “-mers” are chemically attached or polymerized together. Linking infinite strips of construction paper together to create paper garlands or attached together hundreds of paper clips to make chains, or stringing beads helps you to visualize the polymers. Polymers can occur naturally and can be made to serve particular needs. The polymers that can be manufactured can be 3-dimensional (3D) systems that do not go once formed. Such networks are called Thermoset polymers. Epoxy resins which are used in 2-part adhesives are thermoset plastics. These manufactured polymers can also be a 1-dimensional chain that can be melted. These chains are Thermoplastic polymers and can also be called Linear polymers. The Cups, Plastic bottles, Films, and fibers are Thermoplastic plastics.

Polymers are found in nature. The ultimate natural polymers are deoxyribonucleic acid i.e., DNA, and ribonucleic acid i.e., RNA that explain life. Hair, Spider silk, and horn are the protein polymers. A Starch can be a polymer as it has cellulose in wood. We use rubber tree latex and cellulose as raw materials to make fabricated polymeric rubber and plastics. The very first synthetic manufactured plastic was Bakelite, in the year 1909 for telephone casing and electrical components. The first produced polymeric fiber was Rayon, from cellulose, in the year 1910. Nylon was invented in the year 1935 while trying synthetic spider silk.

Structures of Polymers:

Many general classes of polymers are formed of hydrocarbons, hydrogen, and compounds of carbon. The polymers are exactly made of carbon atoms bonded together, one to the next, into large chains that are called the backbone of the polymer. We can attach one or more other atoms to each carbon atom in the backbone chain. There are polymers that have only carbon and hydrogen atoms. Polyethylene, polybutylene, polystyrene, polypropylene, and polymethyl pentene are examples of these polymers. Polyvinyl chloride (PVC) has a chlorine atom attached to all the carbon backbone. The Teflon has fluorine attached to all the carbon backbone.

Other commonly produced polymers have backbones that have elements other than carbon. Nylons contain nitrogen atoms in the repeated unit of the backbone. Polycarbonates and Polyesters contain an oxygen atom in the backbone. There are also a few polymers that, alternatively of having a carbon backbone, have phosphorus or silicon backbone. These are recognized inorganic polymers.

Different Types of Polymers:

Classification of Polymers

1. Source-Based Classification

Let’s look at the first classification of polymers based on their source of origin.

The easiest method to categorize polymers is by their origin. Natural polymers arise naturally and can be found in natural sources such as plants and animals. Proteins (which have the same structure in humans and animals), Cellulose and Starch (which are present in plants), and Rubber are all common examples (which are harvested from the latex of a plant).

Synthetic polymers are polymers that can be created or synthesized in a lab by humans. These are manufactured commercially for human consumption. Polyethene (a mass-made plastic used in packaging) and Nylon Fibers are two examples of commercially created polymers that we utilize daily (commonly used in our clothes, ropes, etc.)

These polymers are polymers created in a lab by artificially altering natural polymers. These commercially essential polymers are created through a chemical reaction (in a controlled environment). Examples are vulcanized Rubber which is created by crosslinking sulphur to the polymer chains in Natural Rubber, cellulose acetate (rayon), and other materials.

2. Polymer Classification Based on the Structure

Polymers can be classified into three categories based on their structure:

These polymers have a structure that resembles a long straight chain with identical links connecting them. These are made up of monomers that are bonded together to form a lengthy chain. These polymers have a higher melting point and density than others. PVC is a good illustration of this (Poly-vinyl chloride). This polymer is commonly used in the manufacture of electrical cables and pipes.

These types of polymers have the structure of branches sprouting at random places from a single linear chain, as the name implies. Monomers combine to form a long straight chain with branching chains of various lengths. The polymers are not tightly packed together as a result of their branches. They have a low melting point and density: plastic bags and general-purpose containers made of low-density polyethene (LDPE).

Monomers are joined together to form a three-dimensional network in this type of polymer. Because they are made up of bivalent or trivalent molecules, the monomers have strong covalent bonds. These polymers are brittle and difficult to work with. Examples are bakelite (used in electrical insulators), Melamine, and other similar materials.

3. The Following Variables Can be Used to Control When Producing a Polymer:

The method in which the polymer is collected can produce either a more or less random alignment of the polymer chains or a fabric in which the chains are aligned in a particular direction.

When you change one or more of these parameters can affect the Linearity of this polymer, its average molecular weight, the tactic of side chains on the polymer backbone, and the density of the product.

Characteristics:

• Polymers are very resistant to chemicals. Consider all the cleaning fluids in your house that are packaged in plastic. Reading the warning labels that explain what happens when the chemical comes in contact with eyes or skin or is ingested will indicate the need for chemical resistance in the plastic packaging. While solvents simply dissolve some plastics, other plastics produce safe, non-breakable packages for aggressive solvents.

• Polymers act equally as electrical and thermal insulators. A walk by your house will strengthen this concept, as you consider all the cords, appliances, electrical outlets and wiring that are made or covered with polymeric materials. Thermal resistance is visible in the kitchen with pan and pot handles made of polymers, the coffee pot handles, the foam core of freezers and refrigerators, microwave cookware, insulated cups, and coolers. The thermal undergarments that many skiers wear are made of polypropylene and the fiberfill in winter jackets is acrylic and polyester.

• The polymers are very light in mass with important degrees of power. Consider the range of applications, from toys to the frame construction of place locations, or from feeble nylon fiber in pantyh
  ose to Kevlar, which have been used in bulletproof vests. Some polymers float on water while others sink immediately. Still, while being compared to the weight of stone, concrete, steel, copper, or aluminum, all plastics are lightweight substances.

• The polymers can be prepared in different ways. Extrusion delivers thin fibers or heavy pipes or films or food bottles. Injection shaping can produce very complex parts or large car body panels. Plastics can be made into drums or be mixed with solvents to become adhesives or paints. Elastomers and some plastics extend and are very flexible. Some plastics are extended in processing to take their shape, such as soft drink bottles. Other polymers can be foamed like polystyrene polyurethane and polyethylene.

• Polymers are substances with a seemingly endless range of features and colors. Polymers have many original properties that can be further improved by a deep range of additives to increase their uses and applications. Polymers can be used to mimic cotton, silk, and wool fibers; porcelain and marble; and aluminum and zinc. Polymers can also make possible products that do not easily come from the natural world, such as clean clear sheets and flexible films.

The Uses of Polymers

Polypropene has a broad range of usage in industries such as stationery, textiles, packaging, plastics, aircraft, construction, rope, toys, etc.

• Polystyrene is one of the most common plastics that is actively used in the packaging industry. Disposable glasses, bottles, toys, containers, trays, plates, tv cabinets, and lids are some of the dairy products used by us that are made up of polystyrene. It can also be used as an insulator.

• Urea-formaldehyde resins are used for making molds, adhesives, laminated sheets, unbreakable containers, etc.

• Bakelite is used for making electrical appliances such as switches, kitchen products, toys, jewelry, firearms, insulators, computer discs, etc.