Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 5th Sem 3152610 Polyurathene Technology Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?V (NEW) EXAMINATION ? WINTER 2020
Subject Code:3152610 Date:01/02/2021
Subject Name:Polyurathene Technology
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Give the Urethane-reaction mechanism for synthesis of flexible
(03)
Polyurethane foam.
(b) Write about the significance of surfactants for the production of PU foams.
(04)
(c) Explain about waste management and environment regulation for solid PU
(07)
foam. waste.
Q.2 (a) Mention various applications of slabstock foams.
(03)
(b) List out the major groups and their sub groups for flexible slabstock foam
(04)
according to chemical structure.
(c) Describe the process operations and reaction zones for the production of
(07)
slabstock foams with schematic representation.
Q.3 (a) List the basic requirements for manufacturing of PU buns.
(03)
(b) Write about the effect of cell gas on Thermal conductivity of PU foam.
(04)
(c) Explain in detail about continuous production of laminating PU rigid foam.
(07)
Q.4 (a) Give the advantages and disadvantages of Shell method for laminating
(03)
panels.
(b) Write about dependence of Thermal conductivity on density of rigid PU
(04)
foam.
(c) Mention the methods for manufacturing of pre-insulated pipes and explain
(07)
it in detail.
Q.5 (a) List out the different types of Polyurethane.
(03)
(b) Write a brief note about Polyol.
(04)
(c) Discuss the Basic Structure of Polyurethane Elastomers with example and
(07)
explain prepolymer route for formation of Polyurethane Elastomers.
Q.6 (a) List out the compounding ingredients used in the manufacturing of
(03)
Polyurethane.
(b) Draw the Structure of Urethane link and Polyurethane.
(04)
(c) Discuss the basic chemistry of Polyurethane with suitable examples.
(07)
Q.7 (a) Give the difference between Hydrolysis and Hydrolytic stability.
(03)
(b) List out the design guidelines used for Injection molded polyurethane parts.
(04)
(c) Explain in detail about manufacturing of Diisocyanates with example.
(07)
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Q.8 (a) List out the different types of Physical Blowing agent used in Polyurethane
(03)
foam manufacturing process.
(b) Give the comparison of physical properties of water as a blowing agent and
(04)
boric acid as a blowing agent.
(c) Discuss in detail about Chain Extender used in Polyurethane manufacturing
(07)
process.
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This post was last modified on 04 March 2021