JNTU III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2008
1. (a) What is ‘Gutta percha’? Explain briefly.
(b) What is Amber? Write its composition and properties.
2. What are the techniques available for polymerization process? Explain each technique briefly.
3. (a) If light scattering and osmotic pressure are measured in the same solvent for the estimation of molecular weight, compare the slopes of the plots of 1/M versus C.
(b) What type of ultra centrifugation experiments are suitable for the random coil polymers.
(a) Dielectric constant
(b) dielectric strength
(c) volume resistivity
(d) surface resistivity
5. (a) Discuss the use of flame-retardants in polymers.
(b) Name few flame-retardants and their uses.
6. (a) Write short notes on the method of production of polypropylene.
(b) Write various structural forms of polypropylene.
7. (a) What are the parameters that are specified to characterize the epoxy resins.
(b) What are the ingradients that contain urea-formaldehyde molding powder?
Explain each preparation steps briefly for making of these powders.
8. (a) What is extrusion? What are the different types of extrusions and explain briefly each of them
(b) Explain calendaring process with suitable example.