Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
ME SEMESTER II EXAMINATION SUMMER 2017
Subject Code: 2724002 Date:26/05/2017
Subject Name: Rubber Blends
Time: 02:30 PM to 05:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q. 1

Justify the role of MG30 rubber as a compatibalizer in NR/NBR blends.


List the factors which affecting the Rubber Blend properties.


Describe the basic problems and solutions for NR/NBR cure system.

Q. 2

Discuss about the resistance to environmental damage by NR/EPM blends.


Short note on: "Sandwich mix cycle".

OR
Q. 2

Explain the dynamic vulcanization of NR/EPM gum blends.

Q. 3

Discuss about the effect of incorporating HV-BR into NR/ENR-25 blends.


Explain in detail about the effect of Polychloroprene content on crosslink distribution physical properties.

OR
Q. 3

Write about the importance of NR/EPM Blends.


Discuss about the blending methods for NR/NBR blends with NR/PMMA graft copolymer.


Discuss in detail about the modification of different EPDM grades also discuss the interaction of modified EPDM Carbon Black.

Q. 4

Explain about the high temperature curing effects on NR/EPDM blends.


Discuss in detail about weathering and ozone testing of NR/EPDM blends for light coloured application.

OR
Q. 4

Describe in detail about the different approaches used for improving NR/EPDM blend properties.


Explain in detail about initial extrusion trails of NR/EPDM blends for extruded profile weather strip.

Q. 5
Explain the formulation, compounding, mixing properties of Food
Product application.

OR
Q. 5
List the analytical methods for rubber blend characterization.
Explain any two in detail.