Download GTU BE/B.Tech 2019 Winter 4th Sem New 2142602 Natural Rubber Science And Technology Question Paper

Enrolment No.

Subject Code: 2142602

GUJARAT TECHNOLOGICAL UNIVERSITY

--- Content provided by⁠ FirstRanker.com ---

BE - SEMESTER- IV (New) EXAMINATION - WINTER 2019

Date: 14/12/2019

Subject Name: Natural Rubber Science & Technology

Time: 10:30 AM TO 01:00 PM

Instructions:

--- Content provided by FirstRanker.com ---

1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.

Q.1

1. (a) What is the difference between network structure of conventional and liquid elastomers? 03

--- Content provided by‌ FirstRanker.com ---

2. (b) Describe the suitable method to achieve carbon black dispersion in liquid polybutadiene rubber. 04
3. (c) Explain in detail about RSS and Pale Crepe grades of natural rubber. 07

Q.2

1. (a) Write about the effect of compounding ingredients on diffusion process. 03
2. (b) Describe the ‘storage hardening’ as an important phenomenon related with natural rubber. 04

--- Content provided by‌ FirstRanker.com ---

3. (c) Discuss in detail about the general features of wax blooming. 07

OR

1. (a) Explain the effect of ‘nature of liquid’ and ‘nature of rubber’ in the diffusion of hydrocarbon liquids and oils. 07
2. (b) List the types of chemical modification on natural rubber. 03
3. (c) Why natural rubber is considered to be very reactive polymer? Describe with suitable explanation. 04

--- Content provided by⁠ FirstRanker.com ---

Q.3

1. (a) Write a short note on Grafting chemistry. 07
2. (b) Define the purpose of chemical modification-of natural rubber. 03
3. (c) Write about [3 + 2] cycloaddition reaction mechanism with suitable example. 04

OR

--- Content provided by​ FirstRanker.com ---

1. (a) Explain the tensile stress-strain behaviour of graft copolymer. 07
2. (b) Write about Hysteresis. 03
3. (c) How can you measure puncture strength? Describe with schematic view of the test. 04

Q.4

1. (a) Discuss in detail about the experimental method for the measurement of elastic modulus throughout the crystallization process. 07

--- Content provided by FirstRanker.com ---

2. (b) Which kind of changes arise to rubber products due to the effect of environmental factors? 03
3. (c) Describe the creep and stress relaxation properties for vulcanized rubber. 04

OR

1. (a) Explain in detail about the tensile modulus variation with crystallization time and crystallization temperature respectively. 07
2. (b) What do you mean by SAM and SAMI related with asphalt rubber in paving application? 03

--- Content provided by​ FirstRanker.com ---

3. (c) Write about the different types of reclaimed rubber. 04

Q.5

1. (a) List the methods used for preparation of powdered rubber. Explain in detail about any two. 07
2. (b) List the uses of reclaimed rubber. 03
3. (c) Write about Heater process for the production of reclaimed rubber. 04

--- Content provided by​ FirstRanker.com ---

OR

1. (a) Discuss about the advantages of powdered rubbers. 07

Total Marks: 70

FirstRanker.com

--- Content provided by⁠ FirstRanker.com ---