Skip to main content

Polyenes and copolymerisation.

Polyenes

  • Polyenes are polyunsaturated organic compounds that contain atleast three alternating double and single carbon-carbon bond. For example polyacetylene, β - carotene.
    Polyenes
    Example of polyene; polyacetylene.
  • These carbon - carbon double bond undergoes an interaction known as conjugation which lead to unusual optical properties of polyenes.
  • Some polyenes are bright in colour which is unusual in hydrocarbons.
  • β-carotene is responsible for the orange colour of carrots.
  • Polyenes are more reactive than simple alkenes and they also have high electrical conductivity.
  • Dienes are related to polyenes in which there is two alternating double and single carbon-carbon bonds.

Copolymerisation

The polymers containing two or more different monomers are called  Copolymers  and  the process of formation of Copolymers is called copolymerisation. Nylon 6,6 is a copolymer.
Let A and B be two monomers. The different types of Copolymers are

1) Random (or Statistical) Copolymers:

In these polymers, the monomers are attached randomly as
Statistical Copolymers.
Random copolymer.

2) Alternating Copolymer:

Here the two monomers are arranged in an alternating manner as
Alternating Copolymers
Alternating Copolymer.

3)Block Copolymer:

Here a long sequence or block of one monomer is attached to the block of second monomer as
Block copolymer.

4)Graft Copolymer:

Here a chain of one monomer is attached to the backbone (main chain) of another monomer as
Graft Copolymer.

Comments

Post a Comment

Popular posts from this blog

Polypropylene (PP)

Polypropylene (PP). Polypropylene (PP) is also known as polypropene. Polypropylene is made from the polymerisation of propylene gas in the presence of Zeiglar Natta catalyst or metallocene catalyst. Polypropylene. Thus propene (or propylene) is the monomer of polypropylene. Polypropylene is a highly flammable material. It is sensitive to microbial attacks, such as bacteria and mold. It exhibits excellent resistance to diluted and concentrated acids, alcohols and bases. Polypropylene is used to make lunch boxes, margarine containers, yogurt pots, syrup bottles etc. Disposable syringes is the most common medical application of polypropylene. Polypropylene rope and twine are very strong and moisture resistant very suitable for marine applications. Polypropylene, highly colorfast, is widely used in manufacturing carpets, rugs and mats. Uses of Polypropylene. Questions on polypropylene; Q1) What is polypropylene? Ans) Polypropylene is a polymer of propylen...
Post a Comment
Read more

Determination of molecular weight of polymers by viscosity method.

Determination of molecular weight of polymers by viscosity method. It is a simple method for determining the molecular weight of polymers. Addition of polymers in the solvent increases the viscosity of the solvent, due to introduction of inhomogeneities by the polymers. If η₀ is the viscosity of the solvent and η is the viscosity of the solution at the same temperature, then the relative viscosity is given by Relative viscosity. Specific viscosity:  It is defined as the relative increase in viscosity and is given as Specific viscosity. Reduced viscosity: It is defined as the relative increase in viscosity per unit concentration (C) of polymer and is given as Reduced viscosity. Intrinsic viscosity: The reduced viscosity is dependent on concentration (C). If a graph is plotted between  reduced viscosity vs concentration then the extraplotation value when C=0 is called intrinsic viscosity. Intrinsic viscosity. Graph of reduced vi...
2 comments
Read more

Difference between organic and inorganic polymers.

Difference between organic and inorganic polymers. Definition Organic polymers are the polymers that essentially contain carbon atom in the backbone. Inorganic polymers are the polymers that have no carbon atom in the backbone. Structure Most organic polymers have simple structures. Almost all inorganic polymers are highly branched and have complex structures. Electrical Conductivity In most of the aqueous solutions, organic polymers are typically poor conductors of electricity and heat. Inorganic polymers in aqueous solutions are good conductors of electricity, this is because they have high ability to ionise and this makes them better conductors. Flammability Organic polymers are flammable whereas inorganic polymers are nonflammable. Effect on nature Organic polymers are environmental friendly as these are biodegradable. Inorganic polymers are not environmental friendly as these are non biodegradable. Examples Organic polymers include polysaccharide...
Post a Comment
Read more