2. Cellulose is the main contituent of most __________ fibres.
3. __________ resins are produced by the condensation polymerisation of formaldehyde with urea or melamine.
4. __________ tubes are good substitude for human blood vessels onrheart by-pass operation.
5. Natural rubber is obtained from latex, which is a colloidal dispersion of rubber in water. Which of the following is used as a coagulant in latex ?
6. Automobile steering wheels are normally made of
7. In a cross linked polymer, the monomeric units are linked together to constitute a three dimensional network. Which of the following is a cross-linked polymer ?
8. 90% of the caprolactum is converted to nylon-6 on its condensation polymerisation in the reactor maintained at a temperature of __________ °C.
9. Out of all the elastomers, natural rubber has the longest elongation range & flexibility of the order of __________ percent.
10. Which of the following low molecular weight (<104 ), soft & waxy polymer is used in chewing gum ?
11. Buna-S is a __________ material.
12. Zeigler - Natta catalyst (AlR3 - AlCl3) is used in the polymerisation of
13. Due to its excellent permeability to air/gas and oxidation resistance, the tubes of automobile tyres is made of
14. The main use of butadiene is
15. Mastication of rubber means
16. Reaction of dimethyl terephthalate (DMT) and ethylene glycol produces
17. Tubeless tyres are made of __________ rubber, which is a co-polymer of isoprene & isobutylene.
18. Density of high density polythene is about __________ gm/c.c.
19. Vinyl flooring is done using __________ sheets.
20. Thiokol is nothing but
21. Transistor parts and refrigerator components are normally made of
22. Dacron (or terylene) fibres as compared to nylon fibres have
23. Orlan fibre which is used as a wool sub stitute is
24. Trade name of __________ is neoprene.
25. SBR is produced by the copolymerisation of butadiene & styrene by employing emulsion polymerisation. The weight ratio of styrene and butadiene is maintained at