Effect of annealed titania on dielectric and mechanical properties of ethylene propylene diene monomer-titania nanocomposites

e-Polymers 2014; 14(4): X–X

Rakesh Manna , Suryakanta Nayak * , Mostafizur Rahaman and Dipak Khastgir *

Effect of annealed titania on dielectric and mechanical properties of ethylene propylene diene monomer-titania nanocomposites Abstract: Flexible ethylene propylene diene monomer

(EPDM)-titania nanocomposites of different composi-

tions were prepared by room temperature mixing using

both neat and annealed titania. All these composites

showed composition-dependent dielectric and mechani-

cal properties, and composites with controlled dielectric

properties could be made through judicial adjustment of

the composition. The effect of moisture/filler heat treat-

ment was also studied and found that composites with

annealed titania showed lower dielectric constant than

composites with normal titania. There was a significant

improvement in mechanical properties, where compos-

ites with 60 parts per hundred parts of titania gave the

optimum tensile strength. The particle size of titania

particles was analyzed by high-resolution transmission

electron microscopy (HRTEM) and a dynamic light scat-

tering technique. The morphology and dispersion of tita-

nia particles in the EPDM matrix were studied by field

emission scanning electron microscopy and HRTEM.

Finally, different dielectric models were compared with

experimental data, and the best match was achieved by

the Lichtenecker model, which can be used as a predic-

tive rule for different volume contents of titania filler in

the EPDM matrix.

Keywords: dielectric properties; EPDM; heat treatment;

mechanical properties; nanocomposites; titania.

DOI 10.1515/epoly-2014-0043

Received March 18 , 2014 ; accepted May 1 , 2014

1 Introduction

For the last decades, enormous research work has been

going on in the field of polymer-ceramic composites,

owing to their novel electronic and electrical properties

(1) . These composites have some potential applications

as integrated decoupling capacitors, acoustic emission

sensors, electronic packaging materials and angular

acceleration accelerometers (2 – 4) . Polymer-ceramic com-

posites can act as good dielectric materials for energy

storage (5, 6) . Selection of the appropriate polymer matrix

and ceramic oxide can lead to the formation of graded die-

lectrics where dielectric properties like dielectric constant

and loss factor can be varied over a wide range by simply

changing the composition of the composites. These com-

posites have good mechanical properties, along with easy

processing, which allows them to be formed into any

typical shape through a simple molding process. Selvin

et al. (7) have reported on the mechanical properties of

TiO 2 -filled polystyrene composites. It has been reported

that the tensile modulus of the composites increases

with the increase in TiO 2 content, but tensile strength

first showed an increase followed by a decrease at higher

loading. The proper selection of matrix polymer for such

composites can give rise to both rigid and flexible ceramic

polymer composites that can be used for various electrical

and electronic applications.

Ceramic materials are brittle, possess medium dielec-

tric strength and require, in many cases, very high tem-

perature to process. But polymers are flexible in nature,

can be processed at much low temperature and also have

high dielectric breakdown voltage (8 – 10) . However, the

combination of these two constituents in a single com-

posite material will give a better performance compared to

individual ones. Recently, many studies have been done

on TiO 2 owing to their remarkable optical and electronic

properties (11 – 16) . There is also available literature on the

dielectric properties of TiO 2 -epoxy composite where the

electrical relaxation dynamics and conductivity have been

discussed by means of broadband dielectric spectroscopy

over a wide range of frequency and temperature range

*Corresponding authors: Suryakanta Nayak and Dipak Khastgir, Rubber Technology Centre, Indian Institute of Technology

Kharagpur, West Bengal-721302, India, Tel.: + 91 9333599963,

Fax: + 91 3222282292, e-mail: [email protected] ,

[email protected]

Rakesh Manna: Rubber Technology Centre, Indian Institute of

Technology Kharagpur, West Bengal-721302, India

Mostafizur Rahaman: Chemical Engineering Department, King Fahd

University of Petroleum and Minerals, Dhahran-31261, Saudi Arabia

Bereitgestellt von | provisional accountAngemeldet | 46.30.84.116

Heruntergeladen am | 03.06.14 09:34

2 R. Manna et al.: Effect of annealed titania on dielectric and mechanical properties of ethylene propylene

at three different filler concentrations (17) . By the heat

treatment of filler, both physisorbed and chemisorbed

moisture can be removed from the filler (titania) surface

and electrically stable titania can be developed. With the

decrease in moisture, the extent of interfacial polarization

decreases. With this heat-treated titania, a stable polymer-

ceramic [ethylene propylene diene monomer (EPDM)-tita-

nia] composite can be developed, as normal titania often

contains variable amounts of moisture.

In the present study, flexible polymer-ceramic nano-

composites were prepared from neat EPDM elastomer and

normal/heat-treated titania as filler. The effect of filler

(normal/heat treated) on both electrical and mechanical

properties was studied extensively. As per the extensive

literature survey, there is no available report regarding the

moisture/heat treatment effect of titania on the electrical

and mechanical properties of EPDM-titania composites.

2 Results and discussion

2.1 Properties of titanium dioxide

In the present investigation, both normal and heat-treated

titania were used in order to determine the effect of mois-

ture on the electrical and mechanical properties of EPDM-

titania nanocomposites. The presence of moisture on the

titania surface was confirmed through thermogravimetric

analysis (TGA), as reported elsewhere (18). According to

this study, titania contains both physisorbed and chem-

isorbed moisture on its surface. The particle size of titania

particles was measured by both transmission electron

microscopy (TEM) and a dynamic light scattering (DLS)

technique as presented in Figure 1 . From Figure 1A, it can

be observed that there were more particles whose size

was < 100 nm, but the average particle size found through

the DLS method was 189.53 nm, which is higher than that

found in the TEM study. The bigger particle size obtained

through the DLS study than that through TEM was due to

the association of water molecules on the titania particles.

2.2 Electrical properties

The resistivity of the composites mainly depended on the

resistivity of the polymer matrix as well as on the contri-

bution of the filler. Direct current (DC) resistivity of the

nanocomposites (containing normal/heat-treated TiO 2 )

was found to decrease with the increase in filler loading

as shown in Figure 2 I. The continuous decrease in DC

120

A

B

100

80

60

Inte

nsity

40

20

00 100 200 300 400

309.

6727

5.53

231.

57

189.

53

142.

39

92.6

Diameter (nm)500 600 700 800

Figure 1 (A) TEM image of the titania powder; (B) particle-size

distribution of the titania particles determined through a DLS

technique.

resistivity with titania loading was due to the lower resis-

tivity value of the titania filler than that of the neat EPDM

matrix. The presence of moisture on the filler surface also

affected the resistivity of the final composites, as EPDM

with heat-treated titania showed higher resistivity as com-

pared to the composites containing normal titania at the

same filler loading. From the figure, it can be observed

that composites containing heat-treated TiO 2 (moisture

free) showed higher resistivity compared to those with

normal titania. As the titania particles contained very

little amount of moisture on their surface, it did not affect

much the DC resistivity of low filler loading composites.

Figure 2II-a and II-b represents the log-log plots

of dielectric constant and loss factor vs. frequency for



R. Manna et al.: Effect of annealed titania on dielectric and mechanical properties of ethylene propylene 3

different EPDM-titania nanocomposites, respectively.

From the figure, it can be observed that both the dielec-

tric constant and the dielectric loss were frequency and

composition dependent. It can also be observed that,

as the filler loading increased, both the dielectric con-

stant and the loss factor increased continuously, but the

composites containing filler loading up to 40 php (parts

per hundred parts) (28.57 wt%) showed only a marginal

change in dielectric constant over the whole frequency

region (10 – 10 6 Hz). Beyond 40 php (28.57 wt%) of titania

loading, the increase was more pronounced at the low-

frequency region. The higher dielectric constant at the

low-frequency region was due to the interfacial polariza-

tion between the EPDM matrix and the titania particles.

At any particular frequency, dielectric loss also increased

with the increase in filler loading. Dielectric constant was

also influenced by the presence of moisture on the titania

surface as presented in Figure 2III (inset: plot of the filler

loading against log ε ″ ’ up to 40 php of titania loading). It

can be observed that composites containing heat-treated

titania showed a lower dielectric constant than compos-

ites containing normal titania at a particular frequency.

The presence of moisture in the filler system greatly

affected the dielectric value of the final nanocomposites

owing to its high dielectric constant ( 2

H 080≈′ε at 20 ° C).

In order to obtain electrically stable titania and to prepare

nanocomposites with controlled dielectric properties, the

filler system should be properly dried for moisture (phys-

isorbed/chemisorbed) removal.

The log f vs. loss tangent (tan δ ) plot for composites

containing filler loadings of 20 – 80 php is presented in

Figure 3 A and B. It can be seen from the figure that one

relaxation peak was observed for composites containing

60 and 80 php of normal titania but no relaxation peaks

were observed for composites containing 20 – 40 php of

titania loading. Titania contains very little amount of

17

2.1

1.8

1.5

1.2

0.9

0.6

4

3

2

1

0

–1

1 2 3 4 5 6

log f

80 php

60 php

40 php

20 php

10 php

0 php10 Hz (untreated TiO2)

1 MHz (untreated TiO2)

1 MHz (heat treated TiO2)

0 10 20 30

8

7

6

5

4

log

ε′log

ε′

log

ε″lo

g ε′

40Filler loading (php)

0 20 40 60 80

Filler loading (php)

10 Hz (heat treated TiO2)

1 KHz (heat treated TiO2)

1 KHz (untreated TiO2)

80 php

60 php

40 php

20 php

10 php

0 php(II)

(III)

(a)

(b)

(I)

Composite with normal TiO2

Composite with heat treated TiO216

15

14

13

12

11

10

40

35

30

25

20

15

10

5

0 10 20

log

(vol

ume

resi

stiv

ity)

(ohm

.cm

)

30 40 50 60 70 80


Figure 2 (I) Effect of filler loading on DC resistivity, (II) log-log plots of the dielectric constant ( ε ′ ) and dielectric loss ( ε ″ ) vs. frequency for

EPDM-TiO 2 composites at various filler loadings, and (III) effect of filler loading on dielectric constant ( ε ′ ) at three different frequencies for

composites containing normal and heat-treated titania.




moisture on its surface based on a TGA study, as reported

elsewhere (18). Because of the lower percentage of mois-

ture on titania surface composites with lower filler,

loading did not show any relaxation. In addition to that,

composites containing heat-treated titania did not show

any relaxation peak over the frequency region, which

confirms that relaxation peaks were present owing to the

presence of moisture on the titania surface. Composites

containing lower loading of normal titania did not show

any relaxation, which may be due to the lower percentage

of moisture on the titania system.

Variation of a specific polarization with filler loading

is shown in Figure 4 A. From this figure, it can be observed

that specific polarization was continuously increased

with the increase in filler concentration at any particular

frequency.

2.3 Mechanical properties

Figure 4B shows the plot of variation of the filler loading

with tensile strength and% elongation at break (% EB) for

different composites containing both normal and heat-

treated titania. It can be observed that both the tensile

strength and the % EB increased continuously up to

60 php of titania loading and that, beyond 60 php of titania

loading, both of these properties decreased. It can be con-

cluded that titania acts as a reinforcing filler for the EPDM

matrix up to a certain loading level. The reinforcing nature

of titania with EPDM may be due to some physicochemical

interaction between the EPDM matrix and the chemisorbed

moisture on the titania surface. As the filler concentration

increased, the polymer-filler interaction decreased and

the filler-filler interaction increased. So, this explains why

beyond 60 php of titania loading both the tensile strength

and the % EB decreased. The presence of moisture on the

titania surface also affected both of these properties, as

the presence of moisture adversely affected the wetting

of the filler particle by polymer chains, which hampered

the polymer-filler interaction there by reducing the tensile

strength and increasing the % EB to some extent.

Both the tensile modulus and the hardness of all

the composites were affected by the presence of mois-

ture on the titania system, as shown in Figure 4C. It can

be observed that both the tensile modulus and the hard-

ness were increased with filler loading, as expected. In

addition, at a particular filler concentration, composites

containing heat-treated titania showed higher tensile

modulus and hardness than composites containing

normal titania. The increase in these properties for com-

posites containing heat-treated filler may be due to the

loss of adsorbed moisture from the titania surface. The

effect of moisture was also studied with tear strength of

different composites as shown in Figure 4D. From this

figure, it can be observed that tear strength increased con-

tinuously with filler loading for composites containing

both normal and heat-treated titania. Moisture had no sig-

nificant effect on tear strength as composites containing

both normal and heat-treated titania showed almost the

same tear values. George et al. (19) reported the dielectric,

mechanical and thermal properties of low-permittivity

polymer-ceramic composites for microelectronic applica-

tions. In their study, they used Li 2 MgSiO

4 (LMS) ceramic

as the filler material, whereas polyethylene (PE) and poly-

styrene (PS) were used as base matrices. It was observed

that tensile strength decreased with the increase in LMS

loading in the PE/PS matrix (19) . From the aforementioned

comparative study, it can be concluded that the increase/

decrease in the properties the of composites depended

on the nature of the materials (polymer/ceramic filler)

used. In our previous work on the dielectric and mechani-

cal properties of PDMS-titania composites, we found that

mechanical properties like tensile strength, % EB and tear

strength decreased with the increase in filler loading (19) .

0.70 php20 php

A B40 php60 php80 php

0 php20 php40 php60 php80 php

0.6

0.5

0.4

0.3

0.2

0.1

0

1 2 3

log f log f

Heat treated TiO2

Tan

δ0.6

0.5

0.4

0.3

0.2

0.1

0

Tan

δ

4 5 6 1 2 3 4 5 6

Figure 3 Log f vs. tan δ for (A) EPDM-normal TiO 2 , (B) EPDM-heat-treated TiO

2 nanocomposites at various filler loadings.




1.0A B

C D

6(a) T.S. (MPa)-normal TiO2

(a) Modulus@100%-normal TiO2TiO2

(b) Modulus@100%-heat treated TiO2

(c) Hardness-normal TiO2

(d) Hardness-heat treated TiO2

Heat treated TiO2

(b) T.S. (MPa)-heat treated TiO2

(c) % EB-normal TiO2

(d) % EB-heat treated TiO2

5

4

3

2

100

% E

long

atio

n at

bre

ak

Har

dnes

s (s

hore

A)

200

300

400

500

Tens

ile s

tren

gth

(MP

a)

Tens

ile m

odul

us (

MP

a)

Tear

str

engt

h (N

/mm

)

1

0 20 40

(a)

(c)

(d)

(b)

60 80Filler loading (php)

0.9

@ 100 Hz

0.8

0.7

0.6

0.5

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0 20 40Filler loading (php)


6030

35

40

45

50

55

6024

22

20

18

16

14

12

10

8

0 20 40 60 80

80

0

Vc (TiO2)

(ε′-1

)/(ε

′+2)

0.03 0.06 0.09 0.12

db

c

a

0.15

Figure 4 (A) Specific polarization [( ε ′ -1)/( ε ′ + 2)] as a function of filler loading (volume fraction) for different composites at 100 Hz. (B) Varia-

tion of tensile strength and % elongation with filler loading. (C) Tensile modulus at 100% and hardness against titania loading. (D) Plots of

tear strength against filler loading.

However, in the present investigation on the “ dielectric

and mechanical properties of ethylene propylene diene

monomer-titania nanocomposites ” , these properties

increased up to a certain filler concentration (60 php),

beyond which they started to decrease.

2.4 Morphology study

The scanning electron microscope images of the cryo-frac-

tured surface of EPDM-TiO 2 nanocomposites containing

different amounts of titania (20 and 40 php) are presented

in Figure 5 A and B. It can be observed from these images

that the filler particles are thoroughly dispersed through-

out the polymer matrix. In the figure, titania particles are

marked by blue arrows and are also well wetted by the

polymer matrix. So, as the loading of titania increased,

more portion of the EPDM matrix was wetted with titania

particles, up to a certain filler concentration. So, the

tensile strength of the composites increased continuously

with filler loading as discussed earlier. The TEM images

of the EPDM-titania composites containing 20 and 40

php of titania are presented in Figure 6 A and B. It can be

observed from the TEM images that the titania particles

are thoroughly distributed in the EPDM matrix and some

particle agglomeration can also be seen at higher loading.

2.5 Comparison of measured permittivity with values predicted by classical dielec-tric mixing rules

The two insulating components of the composites could

not exchange electric charges at their separation surfaces;

this gave rise to Maxwell-Wagner interfacial polarization.

For the present systems, the resulting dispersive behavior

appeared to be located at low frequencies, so that above

1000 Hz it seemed to be reasonable to assume the dielec-

tric permittivity to be almost completely unrelaxed with

respect to this process. Several dielectric mixing models




have been proposed to account for the effective permittiv-

ity ( ε c ) of the two immiscible components of the composite

materials: one made of polymer matrix having dielectric

permittivity ( ε 1 ) and volume fraction ( v

1 ), and another

filled with ceramic fillers having permittivity ( ε 2 ) and

volume fraction ( v 2 = 1- v

1 ). Among those models, models

having spherical particles are of special interest:

(i) The Maxwell-Wagner (20, 21) or Maxwell-Garnett (22)

or Rayleigh (23) or Clausius-Mossotti (24) or Lorentz-

Lorenz (24) or Kerner-B ö ttcher (25) equation:

2 2 1

c 1

1 2 2 2 1

3 ( - )1

2 - ( - )

⎡ ⎤= +⎢ ⎥+⎣ ⎦

ε εε ε

ε ε ε ε

vv

[1a]

(ii) The above equation can also be written as:

c 1 2 1

2

c 1 2 1

- ( - )

2 2=

+ +ε ε ε ε

ε ε ε εv

[1b]

(iii) The Lichtenecker equation (21) .

0

4

6

8

10

12

14

16

A

B

CMaxwell-Wagner

Lichtenecker

Sillars

Jayasundere-Smith

Experimental, 100 Hz

Die

lect

ric c

onst

ant (

ε′)

0.02 0.04 0.06 0.08 0.10 0.12 0.14

Vc (TiO2)

Figure 6 Transmission electron microscope images of cryo-frac-

tured samples: (A) EPDM + 20 php (16.67 wt%) untreated TiO 2 , and

(B) EPDM + 40 php (28.57 wt%) untreated TiO 2 composites, and (C)

experimental ε c data of EPDM-TiO

2 composites at 100 Hz at various

filler contents ( V 2 ), compared with specified models.

Figure 5 Scanning electron microscope images of cryo-fractured

samples: (A) EPDM + 20 php (16.67 wt%) untreated TiO 2 , and (B)

EPDM + 40 php (28.57 wt%) untreated TiO 2 composites.




c 1 1 2 2ln( ) ln( ) ln( )= +ε ε εv v

[2]

The Sillars (20, 26) or Landau-Lifshitz (27) equation

2 2 1

c 1

1 2

3 ( - )1

2

⎡ ⎤= +⎢ ⎥+⎣ ⎦

ε εε ε

ε ε

v

[3]

The Jayasundere-Smith equation (20, 25)

1 2 1

1 1 2 2 2

1 2 1 2

c

1 2 1

1 2 2

1 2 1 2

3 ( - )1 3

( 2 ) ( 2 )

3 ( - )1 3

( 2 ) ( 2 )

⎡ ⎤+ +⎢ ⎥+ +⎣ ⎦=

⎡ ⎤+ +⎢ ⎥+ +⎣ ⎦

ε ε εε ε

ε ε ε εε

ε ε ε

ε ε ε ε

v v v

v v v

[4]

The volume fractions of the filler ( v 2 ) and those of the

polymer ( v 1 ) were calculated by means of the following

relation:

2 2

2

1 2 2

1 2

1

Vol

Vol Vol= =

+ ⎛ ⎞+⎜ ⎟⎝ ⎠

ρ

ρ

mVm m

[5]

where v i , m

i , and ρ

i (for i = 1, 2) respectively represent the

volume, mass, and density of phase i (polymer/filler) of

the composite. The density of neat EPDM elastomer was

ρ 1 = 0.86 g/cm 3 , and the density of titanium dioxide was

ρ 2 ≈ 4.2 g/cm 3 . The filler volume fractions corresponding

to different composites were v 2 = 0.04, 0.08, 0.11, and 0.14

vol%.

Predictions of the above equations, based on differ-

ent assumptions, even if derived within the same theo-

retical approaching scheme, may considerably differ

from one another. For comparison, the theoretical and

experimental values are reported in Figure 6C. The

experimental data sets to which the models were com-

pared are listed in Table 1 . Notably, of all the models,

the Lichtenecker model gave the best agreement to the

experimental data.

Table 1 Dielectric constant of EPDM/titanium dioxide composites

at 100 Hz.

TiO 2 volume fraction ε ′′ (100 Hz)

0.000 4.15

0.04 4.70

0.08 6.58

0.11 17.93

0.14 55.25

1.00 32801.88

Data for filler contents up to 14% and those for pure titanium

dioxide were measured.

3 Summary and conclusions EPDM-titania composites exhibit composition-depend-

ent dielectric properties, where both the dielectric con-

stant and the dielectric loss increased with the increase

in titania content. All the composites show frequency-

dependent dielectric properties, where both the dielec-

tric constant and the dielectric loss increased with the

decrease in frequency due to the increased contribution

of interfacial and space charge polarization. Heat treat-

ment of the titania particles decreased the permittivity

and the dielectric loss of the composites because of loss of

moisture. The addition of titania to the EPDM matrix also

improved the mechanical properties of the composites and

attained an optimum at 60 php of titania loading. Above

this filler loading, the mechanical properties decreased

due to the dilution effect. The titania reinforced the filler

for the EPDM matrix up to a certain filler loading (60

php), as apparent from the tensile test. Different dielectric

models were compared with the experimental data, and

the best match was achieved by the Lichtenecker model,

which can be used as a predictive rule for different volume

contents of the titania filler in the EPDM matrix.

4 Experimental section

4.1 Materials

The EPDM rubber (grade EP 96) was supplied by Yangtse

Petrochemical (Nanjing, China) with an ethylene content

of 66%; the ethylidene norbornene type of EPDM had a

diene content of 5.8% and a Mooney viscosity (ML l + 4

at

100 ° C) of 61. Titanium dioxide (TiO 2 ) was supplied by

Merck Chemicals (India). The curative dicumyl peroxide

(DCP) was purchased from Aldrich Chemical Company

(WI, USA). The co-vulcanizing agent triallyl cyanurate

(TAC) was purchased from E-Merck India Ltd (India). The

antioxidant 2,2,4,-tri methyl 1-1,2-dihydroquinoline (TQ)

was obtained from Lanxess India Orivate Ltd. (India). All

the chemicals except titania were used as received without

further purification. Titania was used with/without heat

treatment at 600 ° C.

4.2 Preparation of EPDM-titania nanocomposites

Heat treatment of titania was done at 600 ° C in order

to remove the adsorbed (physisorbed/chemisorbed)




moisture from the titania surface and to get electrically

stable titania. Mixing of the titania particles (normal/

heat treated) and other ingredients into the EPDM matrix

was done using an internal mixer (-Plasti-Corder, model

PLE 330, Brabender) at room temperature for 6 min with

a shear rate of 45 rpm. Addition of TiO 2 , DCP, TAC, and

TQ into the EPDM matrix was done sequentially as per

Table 2 . Finally, the compounded elastomer was passed

through a two-rolled mill for three to four times to get a

better dispersion of the fillers inside the polymer matrix

and to make them into a sheet form. The cure property

of the compounded elastomer was done at 160 ° C using a

Monsanto Rheometer 100 equipment. The compounded

elastomers were cast into moulds and cured at 160 ° C

for 26 min (obtained from the Monsanto Rheometer 100

equipment) at a pressure of 10 MPa.

Different nanocomposites were designated by using

alphanumeric characters; for example, E 100

T 40

means the

composition of the EPDM elastomer and TiO 2 contained 40

parts of titanium dioxide by weight per hundred parts of

polymer (php) and so on, where “ E ” stands for EPDM and

“ T ” stands for titanium dioxide. In all the compositions,

the other ingredients were kept constant.

4.3 Characterization

Tensile and tear properties were measured using a uni-

versal testing machine (Hounsfield H10KS) in accord-

ance with ASTM D-412 and ASTM D-624, respectively.

The Shore-A hardness of all the nanocomposites and that

of neat elastomer were measured according to ASTM D

2240 using the Durometer Type A equipment from (Shore

Instrument &Mfg. Co., Mineola, NY, USA). The DC volume

resistivity of different nanocomposites was measured

using an Agilent 4339B high-resistance meter coupled

with an Agilent 16008B resistivity cell. The dielectric prop-

erties of the nanocomposites were measured using a pre-

cision LCR meter (Model Quad Tech 7600) coupled with

a homemade cell, which had parallel plate circular elec-

trodes. The morphology and dispersion/distribution of

the particulate titania filler in the elastomer matrix were

studied using a field emission scanning electron micro-

scope (Model SUPRA 40, Carl Zeiss SMT AG, Germany).

The particle size of the titania filler was measured by a

dynamic light scattering technique using a particle size

analyzer (Brookhaven 90 Plus).

Acknowledgments: The authors would like to thank the

Indian Institute of Technology Kharagpur for providing

funding for the research fellowship and research facility.

References 1. Popielarz R, Chiang CK, Nozaki R, Obrzut J. Dielectric properties

of polymer/ferroelectric ceramic composites from 100 Hz to 10

GHz. Macromolecules 2001;34:5910 – 5.

2. Sebastian MT, George S, Anjana PS, Thomas S, Subodh G.

Polyethylene-ceramic composites for electronic packaging appli-

cations. In: International Conference on Microwave, Jaipur, India,

November 21 – 24, 2008.

3. Chahal P, Tummala RR, Allen MG, Swaminathan M. A novel inte-

grated decoupling capacitor for MCM-L technology. IEEE Trans

Comp Pack Manuf Technol Part B. 1998;21(2):184 – 93.

4. Dias CJ, Igreja R, Marat-Mendes R, Inacio P, Marat-Mendes JN,

Das-Gupta DK. Recent Advances in Ceramic-polymer Composite

Electrets. IEEE Tran Dielectr Electr Insul. 2004;11(1):35 – 40.

5. Barber P, Balasubramanian S, Anguchamy Y, Gong S, Wibowo A,

Gao H, Ploehn HJ, Loye HCZ. Polymer composite and nanocom-

posite dielectric materials for pulse power energy storage.

Materials 2009;2:1697 – 733.

6. Murugendrappa MV, Prasad MVNA. Dielectric spectroscopy of

polypyrrole- γ -Fe 2 O

3 composites. Mater Res Bull. 2006;41:

1364 – 9.

7. Selvin TP, Kuruvilla J, Sabu T. Mechanical properties of tita-

nium dioxide-filled polystyrene microcomposites. Mater Lett.

2004;58:281 – 9.

8. Webster JR. Thin film polymer dielectrics for high-voltage

applications under severe environments. M.Sc. Thesis, Electrical

Engineering, Virginia Polytechnic Institute and State University,

Blacksburg, VA; 1998. 95 pp.

9. Liang X, George SM, Weimer AW. Synthesis of a novel porous

polymer/ceramic composite material by low-temperature atomic

layer deposition. Chem Mater. 2007;19:5388 – 94.

Table 2 Formulations of EPDM-TiO 2 nanocomposites.

Ingredients Composition parts by weight per hundred parts of polymer (EPDM)

E 100 T 0 E 100 T 10 E 100 T 20 E 100 T 40 E 100 T 60 E 100 T 80

EPDM 100 100 100 100 100 100

TiO 2 (php/wt%) 0 10 (9.09) 20 (16.67) 40 (28.57) 60 (37.5) 80 (44.45)

DCP 1.5 1.5 1.5 1.5 1.5 1.5

TAC 0.5 0.5 0.5 0.5 0.5 0.5

TQ 1.0 1.0 1.0 1.0 1.0 1.0




10. Bai Y, Cheng ZY, Bharti V, Xu HS, Zhang QM. High-dielectric-

constant ceramic-powder polymer composites. Appl Phys Lett.

2000;76(25):3804 – 6.

11. Ahn JH, Mane RS, Todkar VV, Han SH. Invasion of CdSe nanopar-

ticles for photosensitization of porous TiO 2 . Int J Electrochem

Sci. 2007;2:517 – 22.

12. Karunagaran B, Kim K, Mangalaraj D, Yi J, Velumani S. Struc-

tural, optical and Raman scattering studies on DC magnetron

sputtered titanium dioxide thin films. Sol Energ Mat Sol.

2005;88:199 – 208.

13. Noori FTM, Kbashi HJ, Ali NA, Al-ajaj EA, Jaffer HI. Effect of nano-

composites TiO 2 addition on the dielectric properties of epoxy

resin. Iraq J Phys. 2009;7(8):1 – 5.

14. Bhuvanesh NSP, Gopalakrishnan J. Solid-state chemistry of

early transition-metal oxides containing d 0 and d 1 cations.

J Mater Chem. 1997;7(12):2297 – 306.

15. Oehrlein GS. Oxidation temperature dependence of the dc elec-

trical conduction characteristics and dielectric strength of thin

Ta 2 O

5 films on silicon. J Appl Phys. 1986;59(5):1587 – 95.

16. Nayak S, Sahoo B, Chaki TK, Khastgir D. Development of poly-

urethane-titania nanocomposites as dielectric and piezoelectric

material. RSC Adv. 2013;3:2620 – 31.

17. Kontos GA, Soulintzis AL, Karahaliou PK, Psarras GC, Georga SN,

Krontiras CA, Pisanias MN. Electrical relaxation dynam-

ics in TiO 2 -polymer matrix composites. Express Polym Lett.

2007;1(12):781 – 9.

18. Nayak S, Rahaman M, Pandey AK, Setua DK, Chaki TK, Khast-

gir D. Development of Poly(dimethylsiloxane)-titania nano-

composites with controlled dielectric properties: effect of heat

treatment of titania on electrical properties. J Appl Polym Sci.

2013;127(1):784 – 96.

19. George S, Anjana PS, Sebastian MT. Dielectric, mechanical, and

thermal properties of low-permittivity polymer-ceramic com-

posites for microelectronic applications. Int J Appl Ceram Tec.

2010;7(4):461 – 74.

20. Gallone G, Carpi F, Rossi DD, Levita G, Marchetti A. Dielectric con-

stant enhancement in a silicone elastomer filled with lead magne-

sium niobate-lead titanate. Mater Sci Eng C 2007;27:110 – 6.

21. Carpi F, Rossi DD. Improvement of electromechanical actuating

performances of a silicone dielectric elastomer by dispersion

of titanium dioxide powder. IEEE Tran Dielectr Electr Insul.

2005;12(4):835 – 43.

22. Sihvola AH. Self-consistency aspects of dielectric mixing theo-

ries. IEEE Tran Geosci Remote Sens. 1989;27(4):403 – 15.

23. Nelson SO, You TS. Relationships between microwave permit-

tivities of solid and pulverised plastics. J Phys D: Appl Phys.

1990;23:346 – 53.

24. Jayasundere N, Smith BV. Dielectric constant for binary piezo-

electric 03 composites. J Appl Phys. 1993;73(5):2462 – 6.

25. Bottcher CJF, Bordewijk P. Theory of electric polarization: dielec-

trics in time-dependent fields, vol. 2. Amsterdam: Elsevier;

1978; pp. 476 – 9.

26. Tuncer E, Gubanski SM, Nettelblad B. Dielectric relaxation in

dielectric mixtures: Application of the finite element method

and its comparison with dielectric mixture formulas. J Appl Phys.

2001;89:8092 – 100.

27. Landau LD, Lifshitz EM, Pitaevskii LP. Electrodynamics of con-

tinuous media, 2nd ed. Oxford: Pergamon Press; 1984.



Effect of annealed titania on dielectric and mechanical properties of ethylene propylene diene monomer-titania nanocomposites

Documents