Question

Answer the following.
a. Thermocol is produced from which matterial ?

b. Write uses of PVC.

c. Write the natural or manmade row material of the following items.
Matteress, beaker, bangle, chair, gunny bag, knife, pen

d. Which are the main ingredients of glass ?

​e. How the plastic is produced ?

Answer 1

a. Thermocol is produced from complex material called polystyrene. It transforms into liquid state on heating at more than 100^oc and returns to solid state on cooling.

b. Uses of PVC(Polyvinyl chloride):

• It is used for making bottles.
• It is used for making material for pipes.
• It is used for making handbags.
• It is used for making electric cable insulation.
• It is used for making high quality furniture.
• It is used for making ropes.
• It is used for making toys.
• It is used for making raincoat.

c.

Substances	Material
Mattressplasticity	Thermoplastic(Polypropylene)
Beaker	Silica glass
Bangle	Gold, silver, platinum, glass, wood,plastic
Chair	Thermoplastic(Polypropylene)
Gunny bag	Hessian(burlap) formed from jute
broom	Plastic, corn husks
Knife	Carbon steel, stainless steel, cobalt and titanium alloys
Pen	Brass which is an alloy of copper and zinc

d. Main ingredients of glass are as follows:

• Sand or Silica
• Sodium Carbonate
• Lime or Calcium Oxide
• Other Additives
• Lead glass: mixture of sand, soda, limestone and lead oxide
• Silica glass: using silica only
• Borosilicate: mixture of sand, soda, boric acid, aluminium oxide
• Alkali silicate glass: mixture of sand, soda
• Optical glass: micture of sand, soda, limestone, barium oxide and boron
• Boron – this changes the thermal and electrical properties of the glass and is used to make Pyrex glassware which can withstand extremes of heat and cold.

e.Plastics are derived from natural, organic materials such as cellulose, coal, natural gas, salt and of crude oil. Crude oil is a complex mixture of thousands of compounds. The production of plastics begins with the distillation of crude oil in an oil refinery. This separates the heavy crude oil into groups of lighter components, called fractions. Each fraction is a mixture of hydrocarbon chains, which differ in terms of the size and structure of their molecules.
Two main processes are used to produce plastics - polymerisation and polycondensation. In a polymerisation reaction, monomers such as ethylene and propylene are linked together to form long polymer chains.In a polycondensation reaction, different monomer units are linked together to form long polymer chains. Each polymer has its own properties, structure and size depending on the nature of monomer different quality plastics are produced.
There are many different types of plastics, and they can be grouped into two main polymer families:

• Thermoplastics (which soften on heating and then harden again on cooling).

• Thermosets (which never soften once they have been moulded).