M.Sc. (Semester IV) (CBCS) Examination Mar/Apr-2018
Polymer Chemistry
STEP-GROWTH OF POLYMERS
Time: 2½ Hours
Max. Marks: 70
Instructions: Attempt 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
Draw the various isomeric structures of xylenol and mention which isomer is commercially useful for resin preparation.
By chemical equation only show steps involved in the preparation of Melamine by urea route.
Write the chemical equation for preparation of PEN. Give its important properties.
By chemical equation only, show the formation of Epichorohydrin.
Illustrate by chemical equation the synthesis of PEEK.
Name the chemical used for curing Novolac-PF resin. Draw structure of curing agent.
List any four important applications of UF resin.
Section II
Q.2
Illustrate the cross linking reaction in epoxy resin and state important properties and applications of epoxy resin, derived from BPA.
07
What are polyimides and polybenzimidazoles Discuss their preparation and important properties.
07
Q.3
Discuss the various preparative methods for polyurethanes. List their important applications.
07
Describe the non phosgene route for preparation of polycarbonate. What are the limitations of this process?
07
Q.4
Discuss in brief, the synthetic method to obtain liquid epoxy resin and solid epoxy resin. List their any two important applications.
07
Describe the various cross linking reactions involved in curing of
Resite
MF-resin
07
Section III
Q.5
Illustrate the synthesis of Kevlar. List its important properties and applications.
05
Explain the effect of styrene and acryl nitrile on structures of cross linked unsaturated network polyesters.
05
Draw the various prepolymer structures of UF resin. A close control of pH is essential in polymerization of UF, Why?
04
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SLR-UF-199
Q.6
Organic compound with molecular formula C6H10 on oxidation in presence of alkaline KMnO4 gives aromatic diacid having molecular formula C8H6O4. The reaction of this diacid with excess of methanol gives diester with molecular formula C10H10O4. The reaction of the diester with diol with molecular formula C4H10O2 in presence of acid catalyst gives commercial polymers called 4GT. Draw the repeating unit structure for this polymer. Justify your conclusions.
05
Describe the mechanism for the formation of imide dimmers during polymerization of 𝛆-Caprolactum.
05
Explain the effect of number of methylene linkages on the properties of polyesters with changes in structure of diol and diacid. Illustrate by suitable examples.
04
Q.7
Write a note on any THREE of the following.
14
Polysulphones preparation and applications
Cross linking reactions in UF resin
Manufacturing process of Nylon-6, 6
Addition type polyimides synthesis and applications
Chemistry of Saturated Network polyesters