POLYMER COMPOUNDING (2008 Pattern) (Sem. -1)
Time :3 Hours] [Max. Marks :100
Instructions to the candidates :
1) Answer question number 1 or 2,3 or 4, 5 or 6 from Section -1. Answer question number 7 or 8, 9 or 10 and 11 or 12 from Section – II.
2) Answers to the two sections should be written on separate answer books.
3) Pigures to the right indicate full marks.
4) Draw neat sketches wherever required.
5) Use of calculator, graph paper is allowed.
6) Assume suitable data if required.
SECTION – I
QI) a) Write a note on mixing indices. 
b) With neat sketches, explain mixing action taking place in tumble blenders. Explain how cross mixing can be improved in different types of tumble blenders. 
c) Explain dispersive mixing. OR
Q2) a) Explain the concept of scale of segregation and intensity of segregation.
Explain limitations of striation thickness as measure of mixing. 
b) Write a note on rate of mixing. 
c) Explain distributive mixing.
Q3) a) Explain the theory of polymer blend compatibilization with suitable examples. 
b) List and explain various specific properties of fillers important during polymer compounding. 
c) Write a note on polymer nanoclay composites. 
Q4) a) Write a note on interfacial agents used to enhance filler – matrix compatibility with suitable examples. 
b) What are polymer composites? Explain the role of the various components in polymer composites. 
c) What are polymer compounds? 
Q5) a) Explain reinforcing effects of 
i) Carbon black.
iii) CaCO Q.
b) Explain the mechanism of working of flame retardants, processing aids and coupling agents. 
Q6) a) Write a note on compounding methods used for making of nano composites. 
b) Explain twin screw extruder compounding lines used for filler polymer compounding. 
SECTION – II
Q7) a) Write a note on reactive extrusion. 
b) Explain the role of various additives used in PVC compounding. 
Q8) a) Write a note on compounding of SBR and natural rubber. 
b) Explain reactive blending with a suitable example. 
c) List the various ingredients used in making dough molding compound from unsaturated polyester resin. 
Q9) a) With a neat sketch, explain the type of mixing achieved in the following mixing sections.
i) Cavity mixers.
ii) Variable depth mixers.  b) Discuss important characteristics of a dispersive mixing section. 
QIO) a) Explain with neat sketch, constructional features of a Bussko – Kneader.
b) Explain mixing action in a turbulent mixing ring. 
c) Explain with a neat sketch a double block head mixing section. 
QU)a) Write a note on melting mechanism in a co-rotating Twin Screw extruders.
b) Explain structure, principle of operation and mixing in a continuous mixer.
c) With suitable sketches, classify twin screw extenders. 
Q12)a) Explain the construction and mixing mechanism in a 2 roll mill. 
b) Explain the construction and mixing mechanism in an internal mixer.