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

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GUJARAT TECHNOLOGICAL UNIVERSITY

SEMESTER-IV(NEW) - EXAMINATION - SUMMER 2019

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Subject Code:2142602 Date:20/05/2019

Subject Name: Natural Rubber Science & Technology

Time:02:30 PM TO 05:00 PM Total Marks: 70

Instructions:

1. Attempt all questions.

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2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.

Q.1

1. Write in brief about SMR L. [03]
2. Give the advantages of TSR over conventional grades. [04]

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3. Discuss in detail about “Ribbed Smoke Sheets” and “Brown and Blanket Crepes” in detail. [07]

Q.2

1. Compare the network structure of conventional and liquid elastomers. [03]
2. What is the alternative method for achieving carbon black dispersion in liquid polybutadiene rubber? [04]
3. Give the methods for preparation of Powdered rubbers. Explain any two in detail. [07]

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OR

1. Discuss about the advantages of Powdered and Particulate rubbers. [07]

Q.3

1. List the stages of development of reactive prepolymer for NR graft copolymers. [03]
2. Write in brief about graft copolymers as thermoplastic rubbers. [04]

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3. Discuss about the effect of compounding on the diffusion of hydrocarbon liquids and oils. [07]

OR

1. What is the relation between tensile strength and grafting efficiency for polystyrene graft copolymer with NR and IR respectively? [03]
2. Give the reaction mechanism for grafting chemistry. [04]
3. Write a short note on Wax Blooming. [07]

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Q.4

1. What do you mean by flexible rubber-steel laminates? [03]
2. How the Puncture test is carried out? Explain with suitable diagram. [04]
3. Describe the types of depolymerized rubber according to the degree of degradation achieved. [07]

OR

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1. Define the Term: “Hysteresis Loss”. Write its practical significance. [03]
2. Give a brief note on ‘Creep and Stress relaxation’. [04]
3. Explain the chemistry of epoxidation with reaction mechanism. [07]

Q.5

1. Write about any two types of Reclaimed rubber. [03]

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2. Describe the “Induction period” in low temperature crystallization process. [04]
3. Write a short note on ‘Rubberized Asphalt’. [07]

OR

1. List the major uses of Reclaimed rubber. [03]
2. Draw the Compression test-piece geometry for measurement of elastic modulus during crystallization process and write about it. [04]

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3. Write a short note on Reclaimator process. [07]

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