Polymers are macromolecules formed by joining a large number of small molecules or monomers in a chain. These monomers’ small repeating units react chemically to form long molecules. the repetition of monomer units can be linear branched or interconnected to form three dimensional networks. Polymers are considered to be either amorphous or crystalline although they may not be completely one or the other. Crystalline polymers are more correctly termed semicrystalline as the measured densities for perfect materials differ from those obtained for such polymers.
1. Nylon threads are made of
- polyester polymer
- polyamide polymer
- polyethylene polymer
- polyvinyl polymer
2. Which of the following is a branched polymer?
- low density polymer
- high density polymer
3. On the basis of mode of formation polymers can be classified:
- as addition polymers only
- as condensation polymers only
- as copolymers
- as addition and condensation polymers
4. The process of heat softening, moulding and cooling to rigidness can be repeated for which plastics?
- thermosetting plastics
- both (a) and (b)
- neither (a) nor (b)
5. The polymer used in making hair synthetic hair wigs is mage up of
6. Which of the following monomers form biodegradable polymers?
- 3-hydroxybutanoic acid + 3-hydroxypentanoic acid
- Glycine + amino caproic acid
- ethylene glycol + phthalic acid
- both a and b
7. In addition polymer, monomer used is
- unsaturated compounds
- saturated compounds
- bifunctional saturated compounds
- trifunctional saturated compounds
8. Polymer formation from monomer starts by
- the condensation reaction between monomers
- the coordinate reaction between monomers
- conversion of monomer to monomer ions by protons
- hydrolysis of monomers
9. Which of the following statements is not correct for fibres?
- Fibres possess high tensile strength and high modulus
- Fibres impart crystalline nature
- Characteristic features of fibres are due to strong intermolecular forces like hydrogen bonding
- All are correct
10. Which of the following does not undergo additional polymerization?
- vinyl chloride
- all of the above undergoes addition polymerizations