M.Sc. (Semester III) (CBCS) Examination Nov/Dec-2018
Polymer Chemistry
MORPHOLOGY AND PHYSICAL CHEMISTRY OF POLYMERS
Time: 2½ Hours
Max. Marks: 70
Instructions: Attempt in all five questions. Questions one is attempt on separate sheet. All questions carry equal marks. Figures to the right indicate full marks. Use of log table and non programmable calculator is allowed
Q.1
Multiple choice questions:
14
Which of the following polymer is highly crystalline in nature?
Branched
Linear
Star shaped
Hyper branched
Formula used for calculation in Mn is
Mn =ΣniMiΣni
Mw =ΣniMi 2Σni Mn
Mz =ΣniMi2Σni Mi2
Mw =ΣniMi 2Σni Mn2
Which of the following degradation is more economical valuable??
Random
Chain
Thermal
Oxidative
Cohesive energy is given by equation




Fringed Micelle concept is used to describe nature of
Crysatallites
Spherulites
Polydespersity Index
Viscosity
By using viscometer, which type of average MW is calculated?
Mw
Mn
Mv
Mz
The Ultra Sonic Degradation is causes at frequency
15000 Hz
20000 Hz
18000 Hz
10,000 Hz
Which of the following body is polycrystalline in nature?
Single Crystal
Crystallite
Spherulites
Shish Kebab
Presence of bulky group in polymer structure results
Decrease in Crysallanity
Increase in Crysallanity
Increase in Tg
Both and
10) Mn is calculated by
Osmometer
Viscometer
Light Scattering
DTA
11) What is the effect of electron withdrawing groups in polymer structure during degradation?
No effect on MW
Stability Decrease
No change in structure
Stability Increase

12) Unit of solubility parameter in CGS unit is
(cal/cm3)1/2
(joul/m3)1/2
(cal/cm3)3/2
(joul/m3)3/2
13) DSC method is used for determination of
MP
Tg
BP
Tmax
14) The value of ratio of Mw and for Mn for mono disperse polymer is called
GPC
PBI
MWD
PDI
Q.2
a)Answer the following (any four)
08
Define the term solubility parameter? Write down its importance for polymer solution.
Name the methods used for determination of Mn and Mw .
Name the various products obtained during degradation of PS
Which polymers have better mechanical properties, rapid cooled one or slowly cooled one?
Expand the terms SAXS and WAXS.
b)Write notes on (Any two)
06
Viscometer and MW of polymers.
Photodegradation in PMMA.
Formation of Polymer Single Crystal
Q.3
a)Answer the following(Any two)
08
Describe the Dilatometer method for determination Tg of polymers.
Draw MW distribution curves for polymers and write down the equations for determination of different types MW of polymers.
Discuss the mechanical degradation in polymers with suitable example.
b)Answer he following (Any one)
06
Obtain the equating showing relationship between unperturbed dimension and intrinsic viscosity of a polymer.
Using suitable diagram, explain the formation of micro fibrils in natural polymer.
Q.4
a)Answer the following (Any two)
10
Explain the End Group Analysis method used for determination of MW of polymers.
Describe the thermal degradation in PVC in detail.
Discuss the various thermodynamic factors responsible for polymer dissolution.
b)Answer the following (Any one)
04
Discuss the various factors affecting on nature of DSC curves in polymers.
Two fractions of polymers having MW 5000 with its 50 molecules and 6000 with its 75 molecules are mixed together. Calculate Mn for polymer mixture.
Q.5
Answer the following (Any Two)
14
a)Describe the oxidative degradation process in Natural Rubber in detail.
b)Explain the Hildebrand and Scott equation for enthalpy change. Write down the limitations of Hildebrand and Scott equation.
c)In brief, discuss the various factors affecting on Tg of polymers.