6. What is monomer?
G. Short Answer Type Questions:
1.
Define polymerisation. Name two polymers.
2. What are blended fibres?
3. Write difference between thermoplastics and thermosetting plastics.
4. Write uses of polythene.
5. Write a note on melamine.
H. Long Answer Type Questions:
1. What are natural and man-made material? Give two examples of each.
2. Mention the uses of cotton fibre and jute fibre.
3. Mention two advantages and two disadvantages of synthetic fibres.
4. Mention the general characteristics of synthetic plastics.
5. Mention a few problems associated with the excessive use of a synthetic materials.
ACTIVITY CORNER
Quiz Questions:
1. Polyester is a synthetic fibrous material. (True/False)
2. Acrylic is used for making lenses, aircraft, window screens. (True/False)
3. Sterilised cotton is used as an absorbant in hospitals. (True/False)
Symposium:
Avoid plastics as far as possible.
Answers
A monomer is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.
G:-
1.The two major types of polymerization are addition polymerization and condensation polymerization. In addition polymerization, electrons from a double-bond are used to form bonds between other monomers, like in the process used to make polyethylene.
2.Blended fibres are a combination of two or more fibres to give a new material fibre of desired properties. The parent fibre could be of any material. The new variant formed is a combination of the good properties inherited from the parent fibres.
4.The many uses of Polythene
=} Dustbin liners.
=} Hoses/tubes.
=} Insulation.
=} Plastic Bottles.
=} Protective packaging.
=} Door mat for wet feet.
=} Tabards.
=} Kids play mats.
3.The primary difference between the two is that Thermoset is a material that strengthens when heated, but cannot be remolded or heated after the initial forming, while thermoplastics can be reheated, remolded, and cooled as necessary without causing any chemical changes.
5.melamine, also called cyanuramide or triaminotriazine, a colourless crystalline substance belonging to the family of heterocyclic organic compounds, which are used principally as a starting material for the manufacture of synthetic resins. Melamine is rich in nitrogen, a property that is similar to protein.
H:-
1. Natural material refers to the materials which are obtained from the Nature . ex : wood , medicines , herbs etc. Man made materials are those materials that are made by men . ex: chair , table , cellphones etc.
2.Jute is used chiefly to make cloth for wrapping bales of raw cotton, and to make sacks and coarse cloth. The fibers are also woven into curtains, chair coverings, carpets. Cotton fibre is used to manufacture hydrophile cotton (cotton wool), compress, gauze bandage, and cotton swabs.
Answer:
6.monomer is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.
1.The two major types of polymerization are addition polymerization and condensation polymerization. In addition polymerization, electrons from a double-bond are used to form bonds between other monomers, like in the process used to make polyethylene.
2.Blended fibres are a combination of two or more fibres to give a new material fibre of desired properties. The parent fibre could be of any material. The new variant formed is a combination of the good properties inherited from the parent fibres.
3.Definition of Thermoplastic
A thermoplastic refers to a plastic polymer material that can become mouldable or pliable at a particular temperature. Furthermore, the solidification of thermoplastic happens upon cooling down. Moreover, the molecular weight of thermoplastics tends to be high.
Definition of Thermosetting Plastic
A thermosetting plastic refers to a polymer that becomes rigid in an irreversible manner on the application of heat. Furthermore, such a material can also be called as a thermosetting polymer or thermoset. Moreover, such materials have polymers that, during the curing process, cross-link together so as to form an irreversible chemical bond.
4.The many uses of Polythene
The many uses of PolytheneDustbin liners.
The many uses of PolytheneDustbin liners.Hoses/tubes.
The many uses of PolytheneDustbin liners.Hoses/tubes.Insulation.
The many uses of PolytheneDustbin liners.Hoses/tubes.Insulation.Plastic Bottles.
The many uses of PolytheneDustbin liners.Hoses/tubes.Insulation.Plastic Bottles.Protective packaging.
The many uses of PolytheneDustbin liners.Hoses/tubes.Insulation.Plastic Bottles.Protective packaging.Door mat for wet feet.
The many uses of PolytheneDustbin liners.Hoses/tubes.Insulation.Plastic Bottles.Protective packaging.Door mat for wet feet.Tabards.
The many uses of PolytheneDustbin liners.Hoses/tubes.Insulation.Plastic Bottles.Protective packaging.Door mat for wet feet.Tabards.Kids play mats.
5.
melamine, also called cyanuramide or triaminotriazine, a colourless crystalline substance belonging to the family of heterocyclic organic compounds, which are used principally as a starting material for the manufacture of synthetic resins. Melamine is rich in nitrogen, a property that is similar to protein.