Polymerization Reactions The chemical reaction in which high molecular mass molecules are formed from monomers is known as polymerization. There are two basic types of polymerization, chain-reaction (or addition) and step-reaction (or condensation) polymerization.
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How are polymers different from other molecules?
One major difference between polymers and small molecules (monomers) are the characteristics that polymers exhibit. Polymers normally have higher viscosities, higher boiling points and can show improved mechanical strength over small molecules (monomers).
What type of reaction is used to form polymers?
There are two basic ways to form polymers: (a) linking small molecules together, a type of addition reaction, and (b) combining two molecules (of the same or different type) with the elimination of a stable small molecule such as water.
What are the different types of polymerization reaction?
- Condensation Polymerization.
- Polyamides.
- Polyesters.
- Phenol-Formaldehyde Polymer.
- Melamine – Formaldehyde Polymer.
- Also Read: Chemical Bonding.
How do polymers differ from small chemical compounds?
Unlike simpler pure compounds, most polymers are not composed of identical molecules. The HDPE molecules, for example, are all long carbon chains, but the lengths may vary by thousands of monomer units. Because of this, polymer molecular weights are usually given as averages.
How is a polymer different from a simple molecular solid?
Pure crystalline solids have definite melting points, but polymers, if they melt at all, exhibit a more complex behavior. At low temperatures, the tangled polymer chains tend to behave as rigid glasses.
What are some properties of polymers?
Some of the useful properties of various engineering polymers are high strength or modulus to weight ratios (light weight but comparatively stiff and strong), toughness, resilience, resistance to corrosion, lack of conductivity (heat and electrical), color, transparency, processing, and low cost.
What is the role of polymers in organic chemistry?
Organic polymers play a crucial role in living things, providing basic structural materials and participating in vital life processes. For example, the solid parts of all plants are composed of polymers. These include cellulose, lignin, and various resins.
What process is used to produce polymers?
Polymerization is the process to create polymers. These polymers are then processed to make various kinds of plastic products. During polymerization, smaller molecules, called monomers or building blocks, are chemically combined to create larger molecules or a macromolecule.
What are the advantages of polymers over metals?
Polymers are more resistant to chemicals than their metal counterparts. Polymer parts do not require post-treatment finishing efforts, unlike metal. Polymer and composite materials are up to ten times lighter than typical metals. Polymers are naturally radar absorbent as well as thermally and electrically insulating.
Is polymerization endothermic or exothermic?
Generally, polymerization is an exothermic reaction. The polymerisation is the reaction in which the monomers combine to form polymers.
What is polymerization reaction give an example?
This process is called polymerisation.
E.g. : Formation of polyethene form ethene and reaction of hexamethylene diamine and adipic acid leading to the formation of Nylon 6,6 are examples of two different types of polymerisation reactions .
How can you classify the polymerization process?
There are two main classes of polymerization reaction mechanisms: step-growth polymerization and chain-growth polymerization.
How do polymers have different physical properties?
Why do different polymers have different properties? Answer: They have different chemical compositions (different monomer units), different structures, different ways of being fabricated, etc.
What does polymer mean in chemistry?
Polymers are substances composed of macromolecules, very large molecules with molecular weights ranging from a few thousand to as high as millions of grams/mole.
What is the advantage of making polymers from simpler monomers?
The advantage of polymers is that: (1) an infinite diversity of structures can be produced with a limited number of starting materials (Xn where X = number of different types of monomers, X = lenght of polymer); (2) a modular construction allows for ease in recycling the monomers; when a particular polymer is no longer …
Why do polymers have no definite melting point?
The crystalline portion of the polymer is a nonequilibrium distribution of a large number of crystallites of different sizes and in different environments. They all do not melt at exactly the same temperature.
Why are the properties of polymers more greatly influenced by intermolecular forces than small molecules?
Because polymer molecules are so large, though, the magnitude of their intermolecular forces can vastly exceed those between small molecules. The presence of strong intermolecular forces is one of the main factors leading to the unique physical properties of polymers.
What do all polymers have in common?
A polymer is made up of a number of joined-together monomers. One way of thinking about polymers is like a chain of connected-up paperclips. A polymer is a large molecule made up of smaller, joined-together molecules called monomers.
What is polymer and its characteristics?
Monomers / Polymers / Mers. Monomers: The simple molecules that are covalently bonded into long chains are called monomers. Long chain molecule formed from the monomer units is called a polymer. The chemical process by which the. monomers are chemically combined into.
What factors affect polymer properties?
Numerous factors affect various mechanical properties of polymers, in- cluding molecular weight, processing, extent and distribution of crystallinity, composition of polymer, and use temperature.
What is the importance of polymers?
Polymers help us to save energy, with lighter vehicles and insulated buildings; package consumable goods; reduce land use and fertilisers, thanks to synthetic fibres; preserve other materials using coatings; and save lives by way of countless medical applications.
Are polymers organic or inorganic chemistry?
The polymers can be classified as organic and inorganic polymers. It is well known that organic polymers consist primarily of carbon and hydrogen atoms and frequently along with some heteroatom such as oxygen, nitrogen, and sulfur.
Which of the following is true for polymers?
Which of the following is true for polymers? Explanation: Polymeric molecules are aggregates of a large number of monomer units and possess high molecular mass.
Why are polymers such a popular material choice?
It’s durability, strength and moldability make plastic the material of choice for products designed to protect and improve human health. 2. It never needs to get out of the kitchen. While it’s not indestructible (what is?), with the correct additives package plastic is good at resisting temperature fluctuations.