This set of Polymer Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Other Plastic Materials”.
1. Which of the following monomer molecule does cumarone and indene resemble to?
Explanation: Cumarone and Indene are aromatic in nature and bear a vinylic kind of structure attached to aromatic ring, that’s why the closely resemble s to styrene.
2. Which catalyst is used in the resinification reaction of cumarone and indene?
a) nitric acid
b) sulphuric acid
c) stearic acid
d) boron trifluoride
Explanation: In the resinification reaction of cumarone and indene, they are polymerized in the crude naptha without separation using sulphuric acid as the ionic catalyst.
3. How should the temperature be kept to prevent premature gelation of of polyimides?
a) 30-40 C
b) 60-80 C
c) 55-65 C
d) 50-55 C
Explanation: The second stage reaction or premature gelation of polyimides can be prevented by using dry reactants in an anhydrous system free from pyromellitic acid and keeping the temperature low i.e. below 50 C.
4. Which of the following diamines is not used to prepare useful polyimides?
a) m-phenylene diamine
c) m-benzylene diamine
Explanation: The diamines that are used to make useful polyimides are m-phenylene diamine, benzidine and 4,4-diaminodiphenylether. M-benzylene diamine cannot be used to prepare polyimides.
5. Which of the following monomer pairs polymerize to give Perlon U?
a) hexamethylene diamine and adipic acid
b) hexamethylene diisocyanate and 1,4-butanediol
c) hexamethylene diamine and 1,4-butanediol
d) hexamethylene diisocyanate and adipic acid
Explanation: Perlon U is chemically known as polyurethane and is prepared by the rearrangement polymerization of hexamethylene diisocyanate and 1,4-butanediol by a step-growth mechanism.
6. Which of the following properties of polyurethane rubbers is incorrect as compared to other rubbers?
a) higher tensile strength
b) excellent abrasion resistance
c) excellent resistance to oxygen
d) excellent resistance to acids
Explanation: The polyurethane rubbers have higher tensile strength than any other rubber, excellent abrasion resistance and resistance to oxygen and ozone. However they are less resistant to acids and alkalies than other conventional rubbers.
7. Where is the polyurethane foams extensively used as?
b) paint rollers
c) printing rollers
d) fabric coatings
Explanation: Polyurethane foams are extensively used as paint rollers, cushioning materials, soft backing or padding, etc. polyurethane rubbers are used as printing rollers and fabric coatings.
8. The ester interchange method is more favoured than direct phosgenation of bisphenol A for the production of polycarbonates. State true or false.
Explanation: Direct phosgenation reaction is better done in the presence of solvents and even diluted with certain other solvents. Thus, the ester interchange method is more favoured as it allows avoidance of handling of toxic and inflammable solvents and thus allowing avoidance of costs of solvents and solvent recovery.
9. Which of the following monomer pairs polymerize to give epoxy resin?
a) epichlorohydrin and bisphenol A
b) bisphenol A and diphenyl carbonate
c) bisphenol A and phosgene
d) none of the mentioned
Explanation: The polycondensation reaction between epichlorohydrin and bisphenol A gives epoxy resin as the product. The other two monomer pairs react and polymerize to give polycarbonates.
10. What is the use of epoxy resin from commercial point of view?
a) as strength adhesives
b) as cementing agents
c) cast objects and laminates
d) all of the mentioned
Explanation: The epoxy resins are especially used as high strength adhesives, cementing agents in building industry and also in glass fibre reinforced cast objects and laminates.
11. What is the common name of the polymer poly (ethylene terephthalate)?
Explanation: Poly (ethylene terephthalate) is commonly known as Dacron or Terylene.
12. What is the common or brand name of the polymer polyacrylonitrile?
Explanation: The common brand name of poly acrylonitrile (PAN) is Orlon.
Sanfoundry Global Education & Learning Series – Polymer Engineering.
To practice all areas of Polymer Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.