Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 5th Sem New 2152601 Vulcanisation Previous Question Paper
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?V (NEW) EXAMINATION ? WINTER 2018
Subject Code:2152601 Date:27/11/2018
Subject Name:Vulcanisation
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Draw figures wherever necessary
Q.1 (a) Which rubbers are generally preferred for sulphur vulcanization? Why? 03
Q.1 (b) Write in brief on vulcanization of thick rubber article. 04
Q.1 (c) Explain the effect of crosslink type and structure on given vulcanizate properties:(i) Fatigue
Properties (ii) Ageing Behavior (iii)Permanent Set
07
Q.2 (a) How an assessment of State of Cure is done by physical method? 03
Q.2 (b) Write a short note on shawbury curometer. 04
Q.2 (c) Discuss the limitations of vulcanization temperature. 07
OR
Q.2 (c) Discuss the principle, construction and working of Oscillating Disc Rheometer(ODR). 07
Q.3 (a) List out the properties which are optimized in NR vulcanizate with short crosslinks. 03
Q.3 (b) Explain the competing reactions occur simultaneously during accelerated sulphur vulcanization. 04
Q.3 (c) Write a short note on sulphur donors. 07
OR
Q.3 (a) List out the properties which are optimized in NR vulcanizate with longer crosslinks. 03
Q.3 (b) Explain the post vulcanization network reaction observed during sulphur vulcanization. 04
Q.3 (c) Discuss in detail about the zinc dithiocarbamate accelerators. 07
Q.4 (a) Which peroxide radicals are preferred for rubber vulcanization? 03
Q.4 (b) Explain sulphur monochloride cure with suitable example. 04
Q.4 (c) Discuss in detail about Fluidized Bed Vulcanization. 07
OR
Q.4 (a) What do you mean by co-agent? Also give it?s two examples. 03
Q.4 (b) Explain the vulcanization by phenol formaldehyde resin with suitable example. 04
Q.4 (c) Discuss in detail about the rotational vulcanization technique. 07
Q.5 (a) Write about the vulcanization medium used in case of Liquid Curing Method (LCM). 03
Q.5 (b) Give advantages and disadvantages of superheated steam vulcanization over saturated steam
vulcanization.
04
Q.5 (c) Write on microwave vulcanization equipment. 07
OR
Q.5 (a) For which rubber products, water vulcanization is carried out? Why? 03
Q.5 (b) Which different phases are observed during the free-heating? 04
Q.5 (c) Explain the reaction mechanism of electron beam vulcanization. Also compare irradiation
vulcanization to chemical vulcanization.
07
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This post was last modified on 20 February 2020