Blend Miscibility and Morphology - Polymer Blends and Composites - Engineering Sciences Previous Year Questions

1

2008 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2008

Most plausible value for the Gibb’s free energy change for a miscible blend of two polymers is

A

+5 kJ mol^{-1}

B

+1 kJ mol^{-1}

C

0 kJ mol^{-1}

D

-0.01 kJ mol^{-1}

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2

2008 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2008

A miscible polymer blend consisting of 60% of polymer X (T_g = 208 °C) and 40% of polymer Y (T_g = 100 °C) will show a glass transition temperature in the range of

A

100-120 °C

B

145-165 °C

C

200-220 °C

D

250-270 °C

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3

2009 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2009

Which of the following blends is immiscible ?

A

SAN / PMMA

B

PE / PP

C

PC / PS

D

PET / PBT

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4

2010 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2010

A polymer blend is developed by mixing

A

A polymer and a monomer

B

A polymer and a stabilizer

C

A polymer with another polymer

D

A polymer and a filler

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5

2010 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2010

If the polymeric plasticizer is replaced by nitrile rubber to make the same raincoat, the mass percent of rubber to be blended with PVC is

A

40

B

47

C

53

D

60

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6

2011 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2011

The miscibility in binary polymer blends of poly vinyl fluoride and poly acrylate is governed by which one of the following interactions?

A

dipole-dipole

B

acid-base type

C

hydrogen bonding

D

ion-dipole

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7

2012 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2012

Two miscible polymers A and B are blended in weight ratio of 30:70. If the glass transition temperature, T_g of polymer A is -50°C and that of polymer B is 100°C, then the T_g of the blend is

A

-10.5°C

B

25.0°C

C

37.5°C

D

74.8°C

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8

2014 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2014

Thermodynamically, two polymers with enthalpy of mixing (ΔH) and entropy of mixing (ΔS) form a miscible blend at temperature T when

A

\(\frac{\Delta H}{\Delta S} = 0.5T\)

B

\(\frac{\Delta H}{\Delta S} = T\)

C

\(\frac{\Delta H}{\Delta S} = 1.5T\)

D

\(\frac{\Delta H}{\Delta S} = 2T\)

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9

2017 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2017

The impact strength of polystyrene can be enhanced by blending/mixing with

A

Carbon black

B

PMMA

C

Polybutadiene

D

Glass fibre

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10

2017 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2017

Given T_g of polymer A is 100 °C and that of polymer B is -100 °C, then the T_g of a miscible blend of A and B containing 30 wt% of A is ________ °C (round off final answer to a single digit after decimal point).

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11

2019 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2019

Match the material classification in Column A with the appropriate one in Column B:
(PS=polystyrene, PPO=polyphenylene oxide, PDMS=poly(dimethyl siloxane), PP=polypropylene, PE=polyethylene, PP-g-MA=maleic anhydride grafted PP)
Column A
P. Miscible blend
Q. Immiscible blend
R. Compatibilized blend
S. Polymer composite
Column B
1. PDMS + Fumed silica
2. Nylon 6 + PP-g-MA + PP
3. PS + PPO
4. PE + PP

A

P-3, Q-4, R-2, S-1

B

P-4, Q-3, R-2, S-1

C

P-3, Q-4, R-1, S-2

D

P-4, Q-3, R-1, S-2

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12

2020 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2020

A miscible blend in 1:1 (by weight) composition is formed with

A

Polystyrene and polybutadiene

B

Polystyrene and poly(phenylene oxide)

C

Polystyrene and poly(methyl methacrylate)

D

Polystyrene and poly(dimethyl siloxane)

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13

2021 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2021

Binary polymer blends of polypropylene and polyamide 6 are immiscible. From a thermodynamic viewpoint this is due to ______.

A

low enthalpy of mixing

B

high entropy of mixing

C

high enthalpy of mixing

D

low entropy of mixing

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14

2022 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2022

Weather resistance of high impact polystyrene can be improved by blending polystyrene with

A

Styrene butadiene rubber

B

Natural rubber

C

Ethylene propylene rubber

D

Nitrile rubber

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15

2022 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2022

The blend of polyethylene and polypropylene is

A

Immiscible due to enthalpic constraints

B

Immiscible due to entropic constraints

C

Miscible as they are polyolefins

D

Miscible due to comparable solubility parameters

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16

2022 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2022

The amount of low molecular weight plasticizer with a Tg of -60 °C that must be added to nylon 6 to reduce its Tg from 50 °C to 30 °C is __________ % (rounded off to nearest integer).

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17

2023 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2023

Among the options given, choose the most suitable compatibilizer for blending Polyvinylidene fluoride (PVDF) and Acrylonitrile butadiene styrene (ABS).

A

Styrene-acrylonitrile (SAN)

B

Polybutadiene (PB)

C

Polymethyl methacrylate (PMMA)

D

Nylon 6

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18

2024 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2024

A suitable physical compatibilizer of a binary blend of poly(ethylene) and poly(propylene) is ______.

A

poly(caprolactam)

B

poly(lactic acid)

C

poly(ethylene-block-propylene)

D

poly(carbonate)

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19

2025 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2025

The crystallization of a polymer can only proceed in a temperature range limited to glass transition temperature (T_g) on the lower side, and the equilibrium melting point (T_m^o) on the higher side. Around T_g, the mobility of the polymer chains is lower, while in the proximity of T_m^o, crystal nucleation is inhibited.
In a miscible polymer blend with only one component being crystalline, which option(s) correctly match(es) the Temperature conditions with Events?

Temperature conditions		Events
P	The Tg of the amorphous component is lower than the crystallizable one	1	The temperature range over which crystallization can occur becomes smaller
Q	The Tg of the amorphous component is higher than the crystallizable one	2	Crystallization is inhibited
R	The blend Tg is higher than the Tmo of the crystallizable one	3	The crystallization envelope (Tmo − Tg) is widened
		4	Crystallization is favored

A

P-3; Q-2; R-4

B

P-3; Q-1; R-2

C

P-4; Q-1; R-3

D

P-4; Q-1; R-2

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20

2026 · Engineering Sciences · Polymer Blends and Composites · Blend Miscibility and Morphology

Engineering Sciences (XE) 2026

Which of the following is/are the most appropriate compatibilizer(s) for the polypropylene/Nylon 66 blend?

A

Maleic anhydride grafted polystyrene

B

Maleic anhydride grafted polypropylene

C

Polypropylene-b-polystyrene

D

Glycidyl methacrylate grafted polypropylene

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