GATE Overflow for GATE XE - Questions without answers in Polymer Technology

GATE XE 2026 | Question: 106

Tue, 24 Feb 2026 15:36:45 +0000

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

Maleic anhydride grafted polystyrene
Maleic anhydride grafted polypropylene
Polypropylene-$b$-polystyrene
Glycidyl methacrylate grafted polypropylene

GATE XE 2026 | Question: 108

Tue, 24 Feb 2026 15:35:55 +0000

An insulating polymer is used as a dielectric medium between two capacitor plates. The dielectric constant of the polymer is $5.0$ and the permittivity of vacuum is $8.85 \times 10^{-12} \mathrm{~F} / \mathrm{m}$. The permittivity of the polymer is $\_\_\_\_$ $\times 10^{-12} \mathrm{~F} / \mathrm{m}$ (rounded off to two decimal places).

GATE XE 2026 | Question: 109

Tue, 24 Feb 2026 15:35:53 +0000

Select the correct option to match the Polymer to its Major polymeric constituent from the table given below:

Polymer		Major polymeric constituent
$\text{P}$	Natural rubber	$\text{I}$	Polyisobutylene
$\text{Q}$	Gutta percha	$\text{II}$	Polychloroprene
$\text{R}$	Neoprene	$\text{III}$	trans-$1$, $4$-polyisoprene
$\text{S}$	Butyl rubber	$\text{IV}$	cis-$1$, $4$-polyisoprene

$\text{P-IV ; Q-III ; R-I ; S-II}$
$\text{P-IV ; Q-III ; R-II ; S-I}$
$\text{P-II ; Q-IV ; R-I ; S-III}$
$\text{P-II ; Q-IV ; R-III ; S-I}$

GATE XE 2026 | Question: 112

Tue, 24 Feb 2026 15:34:28 +0000

Select the correct option to match the Compound/Additive to its most suitable Function from the table given below:

Compound/Additive		Function
$\text{P}$	Azocarbonamide	$\text{I}$	Flame retardant
$\text{Q}$	$2$-($2$-hydroxyphenyl)-benzotriazole	$\text{II}$	Coupling agent
$\text{R}$	($3$-Aminopropyl)triethoxysilane	$\text{III}$	Blowing agent
$\text{S}$	Ammonium polyphosphate	$\text{IV}$	UV-absorber

$\text{P-IV ; Q-III ; R-II ; S-I}$
$\text{P-III ; Q-IV ; R-II ; S-I}$
$\text{P-I ; Q-III ; R-II ; S-IV}$
$\text{P-III ; Q-IV ; R-I ; S-II}$

GATE XE 2026 | Question: 114

Tue, 24 Feb 2026 15:33:50 +0000

Select the correct option to match the Initiator(s) with the Method of polymerization from the table given below:

Initiator(s)		Method of polymerization
$\text{P}$	$\mathrm{BF}_{3} / \mathrm{H}_{2} \mathrm{O}$	$\text{I}$	Anionic polymerization
$\text{Q}$	$n-\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{Li}$	$\text{II}$	Cationic polymerization
$\text{R}$	$\mathrm{FeCl}_{2}$ / $\mathrm{K}_{2}$ $\mathrm{~S}_{2}$ $\mathrm{O}_{8}$	$\text{III}$	Coordination addition
$\text{S}$	Metallocene/methylaluminoxane	$\text{IV}$	Free radical addition polymerization

$\text{P-II ; Q-III ; R-IV ; S-I}$
$\text{P-IV ; Q-I ; R-II ; S-III}$
$\text{P-III ; Q-II ; R-IV ; S-I}$
$\text{P-II ; Q-I ; R-IV ; S-III}$

GATE XE 2026 | Question: 116

Tue, 24 Feb 2026 15:33:04 +0000

Which of the following options is/are used to plasticize poly(vinyl chloride) (PVC)?

Addition of vinyl acetate comonomer during the synthesis of PVC
Chlorination of PVC
Addition of di-iso-octyl phthalate during processing of PVC
Addition of dicumyl peroxide during processing of PVC

GATE XE 2026 | Question: 119

Tue, 24 Feb 2026 15:32:57 +0000

Equimolar mixture of terephthalic acid and butylene glycol was taken to synthesize a polyester. The reaction was stopped at $99.6 \%$ conversion of the acid monomer. The weight-average molecular weight ( $\bar{M}_{w}$) of the synthesized polyester is $\_\_\_\_$ $\mathrm{g} / \mathrm{mol}$ (rounded off to the nearest integer).

GATE XE 2025 | Question: 112

Sun, 04 May 2025 19:05:21 +0000

Under which combination of conditions does the glass transition of a polymer increase?

Increase in molecular weight and increase in plasticizer content
Increase in plasticizer content and decrease in cross-linking
Increase in branching and decrease in inter-chain interactions
Increase in chain length and decrease in plasticizer content

GATE XE 2025 | Question: 117

Sun, 04 May 2025 19:05:08 +0000

Match the $\textbf{Polymer}$ with the most suitable $\textbf{Monomer combinations}$ from which it is synthesized.

$\begin{array}{|l|l|l|l|} \hline& \textbf{Polymer} && \textbf{Monomer combinations} \\ \hline P & \text{Polyurethane } & 1 & \text{Maleic acid and propylene glycol } \\
\hline Q & \text{Epoxy } & 2 & \text{Pyromellitic anhydride and } p, p^{\prime} \text{-diamino diphenyl ether} \\ \hline R & \text{Polyimide} & 3 & \text{Epichlorohydrin and bisphenol A} \\ \hline S & \text{Polyester} & 4 & \text{Hexamethylene diisocyanate and tetramethylene glycol } \\ \hline \end{array}$

$\text{P}-4; \text{Q}-3; \text{R}-2; \text{S}-1$
$\text{P}-4; \text{Q}-2; \text{R}-3; \text{S}-1$
$\text{P}-2; \text{Q}-1; \text{R}-4; \text{S}-3$
$\text{P}-2; \text{Q}-3; \text{R}-1; \text{S}-4$

GATE XE 2025 | Question: 118

Sun, 04 May 2025 19:05:04 +0000

Thermoplastic Polyurethane and Polyamide $6$ both contain amide linkages, but when compared to Polyurethane, Polyamide $6$ shows higher melting point due to $\_\_\_\_\_\_\_$.

Higher molecular rigidity
Higher degree of branching
Lower molecular rigidity
Lower degree of crosslinking

GATE XE 2025 | Question: 124

Sun, 04 May 2025 19:04:48 +0000

Which option(s) correctly match(es) the $\textbf{Class of additives}$ used during polymer compounding with the corresponding $\textbf{Chemicals}$?

$$\begin{array}{|l|l|l|l|} \hline & \textbf{Class of additives} & & \textbf{Chemicals} \\ \hline \text{P} & \text{Antioxidant} & 1 & \text{Phthalocyanine} \\ \hline \text{Q} & \text{Flame retardant} & 2 & \text{Di(2-ethylhexyl) phthalate} \\ \hline \text{R} & \text{Plasticizer} & 3 & \text{Tricresyl phosphate} \\ \hline \text{S} & \text{Colorant} & 4 & \text{Phenyl } \beta \text{-napthyl amine} \\ \hline \end{array}$$

$\text{P-4; Q-3; R-2; S-1}$
$\text{P-4; Q-3; R-3; S-1}$
$\text{P-1; Q-2; R-4; S-2}$
$\text{P-2; Q-3; R-1; S-2}$

GATE XE 2025 | Question: 125

Sun, 04 May 2025 19:04:45 +0000

In a set of copolymerization reactions, the following monomer reactivity ratios ($\textbf{r 1}$ and $\textbf{r 2}$) were found for different cases.

$$\begin{array}{|c|c|c|} \hline \textbf{Case} & \textbf{r1} &\textbf{r2} \\
\hline \text{I} & 0.1 & 10 \\ \hline \text{II} & 0.003 & +0.02 \\ \hline \text{III} & 3.4 & 5.6 \\ \hline \text{IV} & 51 & 0.01 \\ \hline
\end{array}$$

Which option(s) correctly identify/identifies the type of copolymerization corresponding to each $\textbf{Case}$?

$\text{I}$ - Ideal copolymerization
$\text{II}$ - Azeotropic copolymerization
$\text{III}$ - Block copolymerization
$\text{IV}$ - Alternating copolymerization

GATE XE 2025 | Question: 127

Sun, 04 May 2025 19:04:37 +0000

The heat of polymerization of ethylene is $25 \mathrm{kcal} / \mathrm{mol}$. The amount of heat generated during the polymerization of $5.6$ $\textsf{kg}$ polyethylene is $\_\_\_\_\_\_\_ \: \mathrm{kcal}$. (Round off to the nearest integer)

GATE XE 2025 | Question: 131

Sun, 04 May 2025 19:04:31 +0000

A rubber contains $70 \mathrm{wt} \%$ butadiene (molar mass $=54 \mathrm{~g} / \mathrm{mol})$, $20 \: \mathrm{wt} \%$ isoprene (molar mass $=68 \mathrm{~g} / \mathrm{mol})$, $5 \: \mathrm{wt} \%$ sulfur and $5 \: \mathrm{wt} \%$ carbon black. Assume that all the sulfur is present in crosslinks.

If each sulfide crosslink contains an average of two sulfur atoms, the percentage of possible crosslinks that are joined by vulcanization is $\_\_\_\_\_ \: \%$. (Round off to one decimal place)

GATE XE 2025 | Question: 144

Sun, 04 May 2025 15:30:34 +0000

Which of the following is the most suitable flexible packaging laminate for dry fruits?

$\textsf{PET/LDPE}$
$\textsf{PS/LDPE}$
$\textsf{BOPP/LDPE}$
$\textsf{Nylon/LDPE}$

GATE XE 2024 | Question: 109

Sun, 21 Jul 2024 16:41:15 +0000

The propagation step of a free radical copolymerization is represented by the following possible reaction steps:

$\text{P1}$: $M_{1}^{*}+M_{1} \rightarrow M_{1}^{*}, \quad$ rate constant $=k_{11}$

$\text{P2}$: $M_{1}^{*}+M_{2} \rightarrow M_{2}^{*}, \quad$ rate constant $=k_{12}$

$\text{P3}$: $M_{2}^{*}+M_{1} \rightarrow M_{1}^{*}, \quad$ rate constant $=k_{21}$

$\text{P4}$: $M_{2}^{*}+M_{2} \rightarrow M_{2}^{*}, \quad$ rate constant $=k_{22}$

where, $M_{1}$ and $M_{2}$ are two monomers and $M_{1}^{*}$ and $M_{2}^{*}$ are the active radicals of $M_{1}$ and $M_{2}$, respectively. $k_{i j}(i, j=1,2)$ represents the rate constant of each step as shown above.

If the reactivity ratios of $M_{1}$ and $M_{2}$ are expressed as: $r_{1}=k_{11} / k_{12}$ and $r_{2}=k_{22} / k_{21}$, respectively, and feed mole ratio, $F$ is expressed as $F=\left[M_{1}\right] /\left[M_{2}\right]$ $\text{(where, $\left[M_{1}\right]$ and $\left[M_{2}\right]$ are the concentrations of $M_{1}$ and $M_{2}$, respectively)}$, the probability of the reaction $P2$ is ___________.

$\frac{r_{1}}{r_{1} F+1}$
$\frac{1}{r_{1} F+1}$
$\frac{1}{r_{2}+F}$
$\frac{r_{2}}{F+r_{2}}$

GATE XE 2024 | Question: 110

Sun, 21 Jul 2024 16:41:14 +0000

Match the following additives to their respective functions for poly$\text{(vinyl chloride)}$ compounding.

Additive	Function
P. Dibutyltin maleate	1. Lubricant
Q. Epoxydized soybean oil	2. Extender
R. Chlorinated paraffin wax	3. Heat stabilizer
S. Calcium stearate	4. Plasticizer

$\text{P-3; Q-4; R-2; S-1}$
$\text{P-2; Q-4; R-1; S-3}$
$\text{P-3; Q-2; R-1; S-4}$
$\mathrm{P}-4 ; \mathrm{Q}-2 ; \mathrm{R}-1 ; \mathrm{S}-3$

GATE XE 2024 | Question: 113

Sun, 21 Jul 2024 16:41:11 +0000

Biaxially oriented poly$\text{(propylene)}$ exhibits high clarity because layering of the crystalline structures

decreases the variation in refractive index across the film thickness
decreases the amount of light scattering
increases the variation in refractive index across the film thickness
increases the amount of light scattering

GATE XE 2023 | Question: 106

Wed, 14 Feb 2024 18:08:40 +0000

\begin{tabular}{|c|c|c|c|c|}
\hline \multirow[t]{6}{*}{ Q. 116} & \multicolumn{4}{|c|}{\begin{tabular}{l}
Among the options given, identify the correct match between the polymers and \\
their glass transition temperatures $\left(\mathrm{T}_{\mathrm{g}}\right)$.
\end{tabular}} \\
\hline & \multicolumn{2}{|c|}{ Polymer } & \multicolumn{2}{|c|}{ Glass transition temperature $\left({ }^{\circ} \mathrm{C}\right)$} \\
\hline & $P$ & High density polyethylene & 1 & $>200$ \\
\hline & Q & Poly(vinyl carbazole) & 2 & 145 to 155 \\
\hline & $\mathrm{R}$ & Polymethyl methacrylate & 3 & -100 to -80 \\
\hline & S & Polycarbonate & 4 & 90 to 100 \\
\hline

& \multicolumn{4}{|c|}{$\mathrm{P}-2 ; \mathrm{Q}-4 ; \mathrm{R}-3 ; \mathrm{S}-1$} \\
\hline
& \multicolumn{4}{|c|}{ P-3; Q-1; R-4; S-2 } \\
\hline
& \multicolumn{4}{|c|}{ P-3; Q-4; R-1; S-2 } \\
\hline
& \multicolumn{4}{|c|}{$\mathrm{P}-4, \mathrm{Q}-2 ; \mathrm{R}-1 ; \mathrm{S}-3$} \\
\hline
\end{tabular}

GATE XE 2023 | Question: 108

Wed, 14 Feb 2024 18:08:37 +0000

\begin{tabular}{l|l|}
Q. 118 & Choose the correct option that best correlates the graphs with the polymerization \\
methods. \\
\hline

& $\mathrm{P}$ - living polymerization; $\mathrm{Q}$ - chain growth; $\mathrm{R}$ - step growth \\
\hline
& $\mathrm{P}$ - chain growth; $\mathrm{Q}$ - living polymerization; $\mathrm{R}$ - step growth \\
\hline
& $\mathrm{P}$ - step growth; $\mathrm{Q}$ - living polymerization; $\mathrm{R}$ - chain growth \\
\hline
& $\mathrm{P}$ - living polymerization; $\mathrm{Q}$ - step growth; $\mathrm{R}$ - chain growth \\
\hline
\end{tabular}

GATE XE 2023 | Question: 110

Wed, 14 Feb 2024 18:08:35 +0000

\begin{tabular}{l|l}
Q.120 & Among the options given, which agents are used to vulcanize or cure rubbers? \\
\hline

& Dicumyl peroxide \\
\hline
& Zinc stearate \\
\hline
& Carbon black \\
\hline
& Dinitrobenzene
\end{tabular}

GATE XE 2023 | Question: 112

Wed, 14 Feb 2024 18:08:33 +0000

\begin{tabular}{l|l}
Q. 122 & \begin{tabular}{l}
Among the options given, identify the correct pair(s) of catalyst and co-catalyst \\
that form a Ziegler-Natta catalyst.
\end{tabular} \\
\hline

& $\mathrm{TiCl}_{3}$ and $\mathrm{Al}\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{Cl}$ \\
\hline
& $\mathrm{ZnCl}_{2}$ and $\mathrm{Al}\left(\mathrm{CH}_{3}\right)_{3}$ \\
\hline
& $\mathrm{TiO}_{2}$ and $\mathrm{Al}\left(\mathrm{CH}_{3}\right)_{3}$ \\
\hline
& $\mathrm{VCl}_{4}$ and $\mathrm{Al}\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{Cl}$ \\
\hline
\end{tabular}

GATE XE 2023 | Question: 114

Wed, 14 Feb 2024 18:08:30 +0000

\begin{tabular}{|c|c|}
\hline Q. 124 & \begin{tabular}{l}
Stress versus elongation profiles for different polymeric materials are shown in the \\
figure. Choose the combination that best describes these profiles.
\end{tabular} \\
\hline & Elongation $\rightarrow$ \\
\hline

& 1-Nylon fibers; 2-Polyethylene; 3-Vulcanized rubber; 4-Polystyrene \\
\hline
& 1-Polyethylene; 2-Vulcanized rubber; 3-Polystyrene; 4-Nylon fibers \\
\hline
& 1-Polystyrene; 2-Nylon fibers; 3-Polyethylene; 4-Vulcanized rubber \\
\hline
& 1-Vulcanized rubber; 2-Polyethylene; 3-Nylon fibers; 4-Polystyrene \\
\hline
\end{tabular}

GATE XE 2022 | Question: 36

Fri, 17 Feb 2023 06:52:10 +0000

In an ideal rubber, the primary factor responsible for elasticity up to small strains is

Change in both enthalpy and entropy
Change in enthalpy, but no change in the entropy
No change in enthalpy, but change in the entropy
Neither a change in enthalpy, nor a change in the entropy

GATE XE 2022 | Question: 39

Fri, 17 Feb 2023 06:52:08 +0000

Which one of the following solvent environments will likely result in swelling of solid polystyrene?

$0.1 \mathrm{M} \mathrm{NaOH}$ in $\mathrm{H}_{2} \mathrm{O}$
$\mathrm{HCl}($ aq.) of $\mathrm{pH}=6$
Distilled water
Benzene