Raw Materials of Polymers — DU B.Sc. Polymer Science Previous Year Question Papers

7. (a) What do you mean by latex compounding? (b) Give the preparation reaction of (i) Vinyl acetate (ii) ethylene glycol. (c) How the dispersion quality can be checked in the latex? (3x5=15) Attempt six questions in all. 1. (a) Write the importance of cracking in petroleum industry. (b) Explain the role of thickening agent in balloon preparation. (c) Discuss primary steps required for mixing of sulphur to latex. (d) Why is petroleum regarded as fossil fuel? (e) What is positex. (5x3=15) 2. (a) How is latex stabilized? Explain the factors which affect the stability of latex. (b) Illustrate the dispersion quality of latex? (c) Discuss coagulant dipping of latex? (3x5=15) 3. (a) Write a short note on latex concentration process. (b) Why Zinc Di -thiocarbamate (ZDC) is used as accelerator in latex product. (c) Name any three additives that are used in latex but not in solid rubber. Write about them? (3x5=15) 4. (a) Discuss the synthesis of ethylene oxide monomer from petrochemical. (b) (i) Synthesis of styrene from ethyl benzene (ii) Synthesis of adipic acid monomer from cyclohexane. (c) Explain the role of bi-functional catalyst in hydrocracking? (3 x 5= 15) 5. (a)What is desalt.ing? What are the main processes? (b) Discuss the crude distillation of petroleum along with flow diagram? (c) Illustrate the catalytic reforming of petroleum? 6. (a) Explain the catalytic cracking of petroleum? (b)What do you mean by second generation petrochemicals? Discuss butadiene route for the synthesis of adiponitrile. (c) Explain the electrochemical process for the production of hexamethylenediamine monomer. (3x5-15)