In case of dry spinning of polymers, the polymer solution in a volatile solvent is forced through the spinnerates into a warm air chamber, where the solvent evaporates leaving behind the polymer in the filament form. Dry spinning is used for _______________ fibres?

Related Mcqs:

1. In case of wet spinning of polymers, the polymer solution is forced through spinnerates into, a coagulating bath to give a filament form. Wet spinning is not used in case of the _____________ fibres?

   A. Viscose rayon
   B. Acrylic
   C. Polyvinyl acetate
   D. Saturated polyester

2. Melt spinning of polymers involves the forcing of polymer melt through spinnerates (fine holes) into an atmosphere kept at a temperature lower than the melting point of the polymer, which causes the fine diameter polymer melt to harden into filaments. Melt spinning is not used in case of the _____________ fibres?

   A. Acrylic
   B. Polyester
   C. Nylon 6:6
   D. Polypropylene

3. In a linear polymer, the monomeric units are linked together to form long straight chains. The cross linked or branched chain polymers compared to linear polymers have higher ___________________?

   A. Densities
   B. Melting point
   C. Tensile strength
   D. Hardness, rigidity & brittleness

4. Dacron (or Treylene) fibres as compared to nylon fibres have_____________________?

   A. Better heat & acid resistant properties
   B. Poorer resistance to alkalis
   C. Poorer dyeability
   D. All A., B. and C.

5. 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 ?

   A. Bakelite (phenol formaldehyde)
   B. Polyester
   C. Polythene
   D. Nylon-6

6. Identify the group in which all the polymers mentioned can be used to make fibres ?

   A. Butadiene copolymers, Polyamides, Urea-formaldehyde
   B. Cellulose derivatives, Polyisoprene, Polyethylene
   C. Cellulose derivatives, Polyamides, Polyurethane
   D. Polypropylene, Poly vinyl chloride, Silicon

7. Cross linked polymers formed from bi-and trifunctional groups in which cross-linkage in three dimensions via few chemical bonding across linear chains occur imparts to the polymer ______________ properties?

   A. Thermoplastic
   B. Thermosetting
   C. Elastometric
   D. Brittleness

8. Which of the following polymers does not belong to the class of Polyacrylate polymer ?

   A. PMMA
   B. Polyacrylonitrile
   C. Poly Ethyl acrylate
   D. None of these

9. Branched chain polymers compared to linear polymers have higher ____________________?

   A. Density
   B. Tensile strength
   C. Melting point
   D. Degree of irregularity in atomic packing

10. Cellulose acetate has very high film permeability among all the polymers of the order of 5000 gm/100 m2. Which of the following polymers has the maximum film elongation (of the order of 100%) ?

    A. Water impermeable cellophane
    B. Polythene
    C. Cellulose acetate
    D. Teflon