M.Sc. (Semester III) (CBCS) Examination Mar/Apr-2018
Polymer Chemistry
BASIC CONCEPTS OF POLYMERIZATION
Time: 2 ½ Hours
Max. Marks: 70
Instructions: Attempt in all five questions. Section-I is compulsory. Attempt any two questions from Section-II Attempt any two questions from Section-III All question carry equal marks. Figures to the right indicate full marks. Use of log table and non programmable calculator is allowed.
Section I
Q.1
Answer the following.
14
How they syncatalyst is obtained? Give one example.
Find the DP for polyester synthesized using AA and BB type monomers in presence of external acid catalyzed having MW=15000.
AIBN cannot be used for cationic polymerization of acrylontrile, Give reason.
What is the difference between a retarder and an inhibitor? Give two examples of each.
Explain how the reactivity ratios of the two monomers give random, block and alternating copolymers.
Why polyesrification is slow at high conversion region?
Define the term "Living Polymerization". Bring out significance of this process.
Section II
Q.2
Explain the main requirements in term of reactivity ratio for a pair of co monomer to obtain various types of copolymers in brief.
07
Define the term Backbiting. Write down the mechanism for the formation of Backbiting phenomenon in manufacture of polyethylene.
07
Q.3
Derive the kinetic expressions for reaction of adipic acid and ethylene glycol to produce polyester in presence of external added mineral acid catalyst.
07
Discuss the group transfer polymerization and list out advantages of this method.
07
Q.4
Describe the Mayo-Lewis method for determination of copolymer composition.
07
Discuss the different types of thermal initiator systems that can be used to initiate radical chain polymerization?
07
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SLR-UF-191
Section III
Q.5
Describe the hydrolytic method for synthesis of Сaprolactum.
05
Calculate the feed ratio of adipic acid and HMDA that should be employed to obtain a polyamide having 15500 at 99.50% conversion.
05
Schematically draw and discuss the different types of copolymers for M1 and M2 vinyl monomers.
04
Q.6
Discuss the chain transfer reactions. What are the applications of chain transfer reactions?
05
Discuss reasons for nonlinearity in the step growth polymerization plot.
05
Explain the role of alcohol used in epoxide polymerization.
04
Q.7
Write a note on any Three of the following.
14
Applications of copolymerization for PVC and Polyethylene
Types of initiators used in anionic polymerization
ADMIT polymerization
ROP of Cyclosiloxanes