Studies on FMCM-41 reinforced cyanate ester nanocomposites for low k applications

Article abstract of DOI:10.1039/c4ra09399b

The continual development of microelectronics needs insulation materials with lower dielectric constant (low k). To accomplish this, a new type of cyclohexyl branched aliphatic chain bridged cyanate ester has been developed by the synthesis of chalcone fr

Full text of DOI:10.1039/c4ra09399b

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Studies on FMCM-41 reinforced cyanate ester
nanocomposites for low k applications†
Cite this: RSC Adv., 2014, 4, 57759
*
Mathivathanan Ariraman, Ramachandran Sasi kumar and Muthukaruppan Alagar
The continual development of microelectronics needs insulation materials with lower dielectric constant
(low k). To accomplish this, a new type of cyclohexyl branched aliphatic chain bridged cyanate ester has
been developed by the synthesis of chalcone from 4-hydroxybenzaldehyde and cyclohexanone, and
followed by reduction. Cyanate ester nanocomposites have been developed by polymerizing cyanate
ester monomer reinforced with varying weight percentages of glycidyl silane functionalized mesoporous
MCM-41 (FMCM-41). Subsequently, the monomer and polymer composites were characterized by
spectral analysis using FTIR (Fourier transform infrared), 1H and 13C NMR (nuclear magnetic resonance)
spectroscopy. The thermal properties were analyzed by TGA (thermogravimetric analysis) and DSC
(differential scanning calorimetry), and morphological studies were carried out by SEM (scanning
electron microscopy) and HRTEM (high resolution transmission electron microscopy). The HRTEM
images clearly indicate the existence of pores, which were responsible for the reduction of the dielectric
constant. The dielectric properties were measured by broadband dielectric spectrometer. From the
dielectric studies it was inferred that 10 wt% of MCM-41 reinforced BCC polymer composites exhibits
the lowest value of dielectric constant of 1.98 at 1 MHz.
Received 28th August 2014
Accepted 20th October 2014
DOI: 10.1039/c4ra09399b
www.rsc.org/advances
addition, the existence of less polar functional groups strongly
reduces the dielectric constant of the matrix due to the reduc-
Introduction
tion of polarization throughout the matrix which in turn results
in lowering the capacitance between the electrodes.8 The ratio
of the permittivity of a substance to that of free space is called
the dielectric constant (k) or relative permittivity (3r). A material
containing non-polar components has less electric dipoles (e.g.
non polar chemical bonds) and a decreased dielectric constant.
The dipole formation is a result of electronic polarization
(displacement of electrons), distortion polarization (displace-
ment of ions), or orientation polarization (displacement of
molecules) in an alternating electric eld. These phenomena
have characteristic dependencies on the frequency of the
alternating electric eld, giving rise to a change in the real and
imaginary part of the dielectric constant between the micro-
wave, ultraviolet, and optical frequency range.1,9 The less polar
aliphatic chains inherently reduce the dipoles between the
electrodes and signicantly reduce the value of the dielectric
constant.
Networked polymer matrices such as polyimide,10 poly-
benzoxazine,5 PEEK,11 and cyanate ester3 have frequently been
reported as low k materials. Among these the cyanate ester (CE)
resin systems have drawn increasing attention due to their
unique properties such as good thermal and mechanical
properties, high glass transition temperature (Tg), radiation
resistance, excellent metal adhesion, compatibility with carbon
ber reinforcements, high ame retardant, low moisture uptake
and excellent electrical insulation behavior.12 Moreover, these
The microelectronics industries are continuously trying to nd
new technological solutions to the reduction of resistance–
capacitance (RC) time delay, power consumption, and ‘cross-
talk’ between nearby interconnects, and to keep pace with the
trend of increasing device densities in ultra-large-scale inte-
grated (ULSI) circuits.1 Generally, microelectronic integrated
circuits consist of interconnected wires which are insulated by
dielectric materials with intra and interlayer capacitance.2 In
order to reduce the capacitance, it is essential to replace the
present insulating materials with the introduction of thin lms
of low dielectric materials (<2.2).3 There are two main routes
normally used to reduce the dielectric constant: (1) by the
preparation of polymer nanocomposites with porous silica
materials such as polyhedraloligomericsilsesquioxane (POSS),4
SBA-15,5 MCM-41,6 etc., and (2) by the introduction of less polar
aliphatic groups into the skeleton.4 Thus, the incorporation of
porous materials into the polymers signicantly reduces the
dielectric constant of the polymer composites because the
intrinsic air/vacuum has a dielectric constant of ꢀ1.7 Subse-
quently, thermally stable dense silica materials drastically
increase the thermal stability of the polymer composites. In
Polymer Composites Lab, Department of Chemical Engineering, A. C. Tech, Anna
University, Chennai-600 025, India. E-mail: mkalagar@yahoo.com
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c4ra09399b
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outstanding performances of CE resin make them an excellent reaction mixture and the resulting precipitate was ltered and
material for radiation resistant and high temperature applica- washed several times with water to yield 90% off brown solid as
tions in aerospace, as adhesives, and as sealants for micro- the nal product.
electronics.13 A cyanate ester resin is a class of thermosetting
polymers and can be prepared by the thermal treatment of a Synthesis of 4,40-(cyclohexane-1,3-diylbis(methylene))
monomer in the absence of any catalyst. It is well known that diphenol (CDD)
the cyanate esters can easily combined with epoxy resin through
covalent bond to form oxazoline ve membered rings with low
curing temperature. It can also be self-polymerized to obtain
cross linked polycyanurate with six member triazine rings.14 The
polycyanurate segment contributes to improved thermal
stability and superior mechanical toughness to other thermo-
setting polymers. Furthermore, the existence of less polar
aliphatic, oxazoline, and triazine inuence the reduction of the
To a stirred solution of BHC in methanol, 10% Pd/C was added
under N2 atmosphere and the reaction atmosphere was subse-
quently changed to hydrogen and stirred for 48 h at RT. Aer
the completion of the reaction, the reaction mixture was ltered
through celite and the ltrate was concentrated under reduced
pressure. The purication procedure is as follows: the resulting
product was dissolved with a small amount of methanol and
cooled with crushed ice, followed by the addition of cold water
value of the dielectric constant of the materials. Recently,
to obtain the precipitate. The precipitate was ltered and
porous silica materials incorporated into cyanate ester polymer
nanocomposites have been reported, and it can be seen that the
10% OG-POSS reinforced bisphenol cyanate ester nano-
composites exhibit the value of dielectric constant of 2.4 which
is lower than that of neat CE matrix.8 In addition, 15% glycidyl
silane functionalized mesoporous silica reinforced poly-
cyanurate exhibits a lower value of dielectric constant (2.11)
than that of neat matrix.3 Hence, reinforcing the varying weight
percentages of porous silica and the existence of less polar
aliphatic long chains in the polymer composites are vital
parameters considered to reduce the dielectric behavior of
insulating materials.
In this context, in the present work we have developed a
cyclohexyl branched aliphatic long chain bridged phenolic
cyanate ester which was cured and reinforced with varying
weight percentages of glycidyl silane functionalized meso-
porous MCM-41 and then characterized and reported. It was
observed that increasing weight percentages of FMCM-41
strongly inuenced the reduction of the value of the dielectric
constant and also signicantly enhanced the thermal stability
of the cyanate ester polymer nanocomposites.
ꢁ
washed several times with water and dried for 12 h at 70 C to
yield 90% pale pink solid product.
1H NMR (DMSO-d6, d, ppm). 9.14 (–OH), 6.93–6.61 (aromatic
protons), 2.63–2.46 (methylene proton), 1.89–1.16 (cycloali-
phatic protons).
Synthesis of 1,3-bis(4-cyanatobenzyl) cyclohexane (BCC)
The synthesis of 1,3-bis(4-cyanatobenzyl) cyclohexane (BCC) is
as follows: CDD was dissolved in dry acetone under nitrogen
atmosphere and then the solution of cyanogen bromide in
acetone was added, followed by the slow addition of triethyl
amine at ꢂ15 ꢁC. Then the temperature was slowly raised to
room temperature and stirred for 1 h. Subsequently, the reac-
tion mixture was ltered and the ltrate was added to cold
water, the precipitate thus obtained was ltered and washed
several times with water and dried for 12 h at 40 ꢁC to yield 88%
pale yellow solid product.
FTIR (KBr cmꢂ1). 2923 (symmetric stretching), 2854 (cyclo-
hexyl CH2 asymmetric stretching), 2238 (CN vibration
stretching).
1H NMR (DMSO-d6, d, ppm). 7.45–7.33 (aromatic protons),
2.49–2.39 (methylene protons), 1.65–1.20 (cycloaliphatic
protons).
Experimental
Materials
13C NMR (DMSO-d6, d, ppm). 150.91, 139.78, 131.28, 115.26
(aromatic carbon), 108.98 (OCN), 51.32 (methylene carbon)
34.15, 26.02, 24.44 (cycloaliphatic carbon).
Analytical grades of 4-hydroxybenzaldehyde, cyclohexanone,
cyanogen bromide (CNBr), triethyl amine (TEA), acetic acid,
sulfuric acid and solvents were purchased from SRL, India.
High purity sodium trisilicate, cetyl trimethylammonium
Synthesis of MCM-41 and functionalization of MCM-41
(FMCM-41)
bromide
(CTAB),
3-(glycidyloxypropyl)trimethoxysilane
MCM-41 was synthesized as per the previous report16,17 as
follows: to an aqueous solution of sodium trisilicate, catalytic
amount of cetyl trimethylammonium bromide (CTAB) was
added drop by drop at room temperature under vigorous stir-
ring and continꢁued for 1 h. Then the resultant gel was heated
for 24 h at 100 C. The jelly mass was cooled to room temper-
(GPTMS) and 10% Pd/C were purchased from Sigma-Aldrich
and were used as received without further purication.
Synthesis of (2E,6E)-2,6-bis(4-hydroxybenzylidene)
cyclohexanone (BHC)
(2E,6E)-2,6-Bis(4-hydroxybenzylidene)cyclohexanone (BHC) was ature, and the pH was adjusted to 10 with acetic acid and it was
synthesized as per the reported procedure.15 To a solution of 4- further heated for 48 h at 100 ꢁC. The pH adjustment and
hydroxybenzaldehyde in a mixture of acetic acid and a catalytic subsequent heating were repeated, and the precipitated MCM-
amount of sulfuric acid, cyclohexanone was added and stirred 41 product was collected by ltration. The product was
ꢁ
for 48 h at room temperature. Aer the completion of the washed with ethanol and calcined in air at 550 C. Aer that,
reaction (monitored by TLC), ice cold water was added to the MCM-41 was functionalized with GPTMS (FMCM-41) as per the
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procedure reported;18 to a suspended solution of MCM-41 in was determined by Broadband Dielectric Spectrometer (BDS),
ethanol, GPTMS was added and sonicated for 1 h and then the NOVOCONTROL Technologies GmbH & Co. (model Concept 80)
ꢁ
mixture was reuxed for 24 h. Aer that the precipitate was at 30 C in the range of 100 Hz to 1 MHz.
ltered and washed with cold ethanol and dried at 70 ꢁC under
reduced vacuum to obtain FMCM-41.
Results and discussion
To investigate the dielectric properties of cyanate ester matrices
and composites (Scheme 2), a less polar aliphatic based cyanate
ester was designed and its molecular structure was conrmed
by NMR and FTIR spectral analysis. For the synthesis of BCC, a
three-step process was used; rst BHC was synthesized and then
the BHC was reduced to get cyclohexyl branched aliphatic chain
bridged phenolic diol (CDD). Finally, CDD was treated with
cyanogen bromide to get BCC (Scheme 1). Fig. 1a presents the
1H NMR spectral data for CDD. The appearance of peaks at
9.14 ppm was attributed to the aromatic OH group and the
peaks in the range from 6.93 to 6.61 ppm correspond to the
aromatic protons. The formation of cyclohexane branched
aliphatic chain linked aromatic diol was conrmed by the
appearance of peaks in the range from 2.63 to 2.46 ppm and
Development of BCC/FMCM-41 nanocomposites
The BCC/FMCM-41 nanocomposites with different concentra-
tions of FMCM-41 (1, 3, 5, 7 and 10%) were prepared according
to Scheme 2; the solution of FMCM-41 in THF was sonicated for
15 minutes, and subsequently BCC was added to that clear
solution and stirred for 15 minutes at 30 ꢁC. The resulting
viscous solution was poured into a respective glass mold and
ꢁ
allowed to evaporate the solvent at 50 C for 3 h and then the
temperature was raised slowly to 210 ꢁC at a heating rate of
20 ꢁC hꢂ1. Aer that the cured lms were removed and
preserved for further characterization.
Characterization
FTIR spectroscopic measurements were conducted on a Bruker 1.89 to 1.16 ppm, which represent the aliphatic shielded region.
1
TENSOR 27 using KBr pellet method. H and 13C NMR spectra Further, the successful formation of cyanate ester was
were recorded on a Bruker 500 NMR spectrometer. Thermog- conrmed by FTIR, 1H and 13C NMR spectral data. Fig. 1b shows
ravimetric measurements were carried out on a Q500 Hi-Res the 1H NMR spectra, the disappearance of the respective
TGA thermogravimetric analyzer from TA instruments. The aromatic OH peak and the retaining of peaks in the ranges from
samples (about 10 mg) were heated from ambient temperature 7.45–7.33 ppm (aromatic protons), 2.49–2.39 ppm (methylene
to 800 ꢁC under a continuous ow of nitrogen (20 mL minꢂ1), at protons) and 1.65–1.20 ppm (cycloaliphatic protons) indicate
a heating rate of 10 C minꢂ1. The calorimetric analysis of the the formation of cyanate ester. Furthermore, the structure
ꢁ
nanocomposites was performed on a Netzsch DSC-200 differ- elucidation was also conrmed by 13C NMR (Fig. 1c); the peak at
ential scanning calorimeter at a heating rate of 10 ꢁC minꢂ1 108.9 was associated with OCN and also the aromatic and
under nitrogen atmosphere. The X-ray photoelectron spectro- aliphatic peaks exhibit in the ranges of 150.91 to 139.8 ppm and
scopic analysis of the samples was carried out using a JEOL JPS- 51.3 to 24.4 ppm, respectively. In addition, the FTIR spectral
9200 photoelectron spectrometer with a monochromatized Al- data (Fig. 1d) was also used to ascertain the OCN formation; the
Ka X-ray source operated at 12 kV and 20 mA.
new absorption band at 2238 cmꢂ1 was attributed to OCN and
High resolution transmission electron microscope (HRTEM) the respective aliphatic vibration bands were observed in the
analysis was carried out on a TECNAI-G2 (model T-30) at an range of 2854 to 2923 cmꢂ1 indicating the successful formation
accelerating voltage of 300 kV. Scanning electron microscope of BCC.
(SEM) measurements were performed using a VEGA 3 TESCAN
The molecular structures of MCM-41 and FMCM-41 were
scanning electron microscope. The piece of lm was xed to the conrmed by FTIR spectra (Fig. 2). FTIR spectra show the bands
surface of double-sided adhesive tape, and the lm was sput- at 1087 cmꢂ1 and 792 cmꢂ1 which correspond to the asym-
tered with gold prior to SEM observation. Dielectric constant metric and symmetric stretching vibrations of the Si–O–Si bond,
Scheme 1 Preparation of BCC cyanate ester.
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Scheme 2 Preparation of BCC/FMCM-41 polymeric nanocomposites.
respectively. The broad absorption band at 3500 cmꢂ1 was
The various chemical bonds of polymer nanocomposites
attributed to the hydroxyl group of MCM-41. In addition, the have their own binding energies and can be evaluated by X-ray
GPTMS functionalized FMCM-41 was conrmed by the photoelectron spectroscopy (XPS), from which the formations of
appearance of new bands at 2933 cmꢂ1 and 2856 cmꢂ1 repre- the chemical structures of the polymer composites were exam-
senting the asymmetric and symmetric stretching modes of the ined. Fig. 3a shows the XPS survey spectra of BCC/10% FMCM-
CH2 group, respectively, and the band appearing at 934 cmꢂ1 41, from which it could be clearly observed that the binding
indicates the presence of a glycidyl group, which conrms the energies of elemental peaks at 283 eV, 531 eV, 398 eV, and
successful functionalization of FMCM-41.
101 eV correspond to C1s, O1s, N1s, and Si2p, respectively.19,20
The cured BCC/FMCM-41 nanocomposites were character- Fig. 3b–d shows the deconvolution peaks of individual elements
ized by FTIR spectra. Fig. S1† shows the disappearance of bands with the characteristic binding energies and is supported by
at 2252 cmꢂ1 (the –OCN group of the cyanate ester) and 943 earlier reports. Consequently, the deconvoluted peaks infer the
cmꢂ1 (the glycidyl group of FMCM-41) and the appearance of a existence of different kinds of bonds in the polymer composites
band at 1645 cmꢂ1 (oxazoline ring) indicates the successful with typical binding energies. Fig. 3b shows the deconvolution
incorporation of FMCM-41 through covalent bonding by cyclic of the C1s signal into three peaks; the major peak at 284.4 eV
oxazoline ring formation between the OCN group of the cyanate corresponds to C–C, C]C and Si–C bonds and the second
ester and the glycidyl group of FMCM-41. Further, the appear- major peak at 285.6 eV is associated to the C–O–C bonds.
ance of bands at 1085 cmꢂ1 and 1365 cmꢂ1 are associated with Subsequently, the third peak at 288.6 eV represents N]C–O
Si–O–Si linkages and the triazine ring, respectively,3 which bonds of the oxazoline ring indicating the successful incorpo-
indicates the successful formation of triazine rings by the self- ration of FMCM-41 through covalent bonds.21 Fig. 3c shows the
polymerization of OCN. The combination of triazine and oxa- deconvolution of the N1s signal into two peaks; the peak at
zoline rings with aliphatic chain and porous silica materials 398.4 eV was assigned to the contribution of the C]N–C bonds
facilitates the reduction of the dielectric constant of the of triazine ring in the polymer composites, implying that the
nanocomposites.
cyanate esters were self-polymerized to form polycyanurate, and
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1
Fig. 1 (a) 1H NMR spectrum of CDD, (b) H NMR spectrum of BCC, (c) 13C NMR spectrum of BCC and (d) FTIR spectrum of BCC monomer.
successful formation of BCC/FMCM-41 polymer nano-
composites through strong covalent bonds could be clearly
ascertained.
The well-dened surface microstructure of the polymer
nanocomposites can be observed by scanning electron micros-
copy (SEM). Fig. 4 shows the SEM images of the surface of the
neat and 10% FMCM-41 reinforced cyanate ester composites,
from which it could be clearly observed that the smooth surface
indicates the homogeneous polymerization of cyanate ester.
The homogeneous distribution of light spots in the BCC/
FMCM-41 polymer composites indicates the covalently
bonded FMCM-41 with the cyanate ester through the oxazoline
ring and inuences the formation of a homogeneous surface.
Fig. 4c describes the results of Si-mapping of the 10% FMCM-41
composite and demonstrates the uniform distribution of MCM-
41 over the surface. Thus, the distinguishable microstructures
of neat and their composites indicate the existence of silica
particles well coordinated with cyanate esters in their compos-
ites which could contribute to sustainable thermal stability.
However, the dielectric features of the polymer composite lms
could not be described and the internal microstructure of the
lms needs to be studied.
In order to understand the internal microstructure of the
composites with varying weight percentages of FMCM-41, they
were studied by high resolution transmission electron micro-
scope (HRTEM). Fig. 5a and b and 5c and d shows the HRTEM
images of MCM-41 and BCC/10% FMCM-41 composites,
respectively. Fig. 5a and b shows the porous nature of the as
Fig. 2 FTIR spectra of MCM-41 and GPTMS functionalized FMCM-41.
the peak at 404.5 eV represents the characteristic shake up
satellite peak which was raised by p–p* transitions in the
aromatic groups.22 In addition, the characteristic O1s signal was
deconvoluted into two peaks; the major peak (Fig. 3d) at 530.9
eV corresponds to C–O and the other one exhibited at 532.2 eV
was assigned to the Si–O–Si bonds. From these observations the
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Fig. 3 XPS spectra of BCC/10% FMCM-41 polymeric nanocomposites.
Fig. 4 SEM images of (a) BCC polymer and (b) BCC/10% FMCM-41, and (c) Si mapping of BCC/10% FMCM-41 polymeric nanocomposite.
prepared MCM-41 materials. Subsequently, the different weight gradual increment of char yield suggests that the presence of
percentages of FMCM-41 were incorporated into the cyanate the triazine ring and oxazoline linked silica materials convert to
ester resin to form cyanate ester nanocomposites. From Fig. 5c form a thermally stable rigid graphene like structure with silica
and d it can be seen that the porous silica nanoparticles are layers at higher temperature.23 In detail, the initial weight loss
surrounded by cyanate ester with distinct distances. In addi- of material below 200 ꢁC is probably due to the removal of
tion, the uniform distribution of the porous silica segments in residual solvent and adsorbed moisture. The major weight loss
the composites provides an ordered air/vacuum in the appro- observed above 300 ꢁC is associated with the decomposition of
priate places. Thus, the denite internal microstructure clearly the polymer network and nally to yield residual chair at 800 ꢁC;
demonstrates the existence of pores which contributes to the these are presented in Table 1. Moreover, the higher decom-
reduction in the value of the dielectric constant of the position temperature and char yield indicate the higher thermal
composites.
stability of the polymer composites, which suggests the utility of
The thermal stability of the BCC/FMCM-41 composites has these composites in the eld of microelectronics as interlayer
been ascertained by thermogravimetric analysis. Fig. 6 shows materials. Fig. S2† shows the DSC proles of neat BCC and BCC/
the TGA curve of different weight ratios of BCC/FMCM-41 10% FMCM-41 composites. The neat BCC exhibits a broad
ꢁ
composites. It can be seen that the increasing weight percent- exothermic peak maximum at 210 C indicating the formation
ages of FMCM-41 increases the thermal stability of the resulting of polycyanurate by the polymerisation of cyanate ester which is
polymer composites and the highest percentage of 10% meso- an exothermic reaction. The BCC/10% FMCM-41 shows the
porous silica exhibits better thermal stability than the neat absence of an exothermic peak indicating the occurrence of
sample indicating that the existence of rigid siloxane and the completely polymerised composites. The existence of absolute
strong covalent bond of the Si–O–Si skeleton contribute to the polymerisation illustrates the uniform structure formation.
enhanced thermal stability of the composites. In addition, the
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Table
1
Thermal and dielectric properties of BCC/FMCM-41
nanocomposites
Char yield
800 ꢁC (%)
Dielectric
constant
Tangent
loss
Sample
BCC
14.88
16.18
16.94
21.49
23.6
2.97
2.87
2.58
2.22
2.08
1.98
0.0233
0.0103
0.0102
0.0102
0.0092
0.0140
BCC/1% FMCM-41
BCC/3% FMCM-41
BCC/5% FMCM-41
BCC/7% FMCM-41
BCC/10% FMCM-
41
25.55
mesoporous materials. Fig. 7, S3† and Table 1 show the
dielectric constant (k) and dielectric loss of the neat and
composite materials. Fig. 7 shows the decreasing trend of
dielectric constant with increasing FMCM-41 content due to the
increasingly porous nature of the silica material which provokes
air in the composites. Fig. 8 presents the log–log form of the
frequency dependency of the dielectric constant for BCC/
FMCM-41 nanocomposites. From Fig. 8 the signicant varia-
tion on dielectric constant with the frequency as well as FMCM-
41 concentration can be seen. The absence of peaks (Fig. 8)
indicates the homogeneous polarization of the nano-
composites. Over the measured frequency region, plateau vari-
ation in dielectric constant was observed in both the lower and
higher frequency regions which demonstrates that low relaxa-
tion and less interfacial polarization of the matrix.24,25 In addi-
tion, the HRTEM images clearly show the existence of pores,
which suggests that the existing pores mainly contribute to the
reduction of the dielectric constant of the material. The neat
polycyanurate exhibits a dielectric constant of 2.98 which is a
lower value than that of the previously reported polycyanurate.
This may be due to the presence of a greater number of less
polarizable aliphatic CH2 groups in the polymer composites.
Fig. 5 HRTEM images of (a and b) MCM-41 and (c and d) BCC/10%
FMCM-41 polymeric nanocomposites.
Microelectronics devices need a lower dielectric constant
material as an interlayer, so it warrants the development of such
novel materials. Recently, researchers have made many efforts
towards the reduction of the dielectric constant of polymeric
materials due to their characteristic physico chemical proper-
ties. Thus, the materials with the lowest dielectric constant
(below 2) have potential applications in electronic devices. In
order to obtain the potential dielectrics, porous silica based
polycyanurate polymer composites were prepared by the poly-
merization of cyanate ester with varying weight percentages of
Fig.
6
Thermogram
curve
BCC/FMCM-41
polymeric Fig. 7 Dielectric constants of BCC and BCC/FMCM-41 polymeric
nanocomposites.
nanocomposites.
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mesoporous FMCM-41 content. Further the thermal stability of
polymer composites was also considerably increased with
increasing Si–O–Si linkage. Data resulting from different
experimental studies suggests that the newly developed class of
skeletal modied cyanate ester polymer composites can be used
as
a
potential insulation material for microelectronic
applications.
Acknowledgements
The authors thank DST (Nanomission), SR/NM/NS-18/2010,
New Delhi, Govt. of India, for the nancial support. The
authors also thank Dr K. Gunasekaran, and Mr M. Kesavan,
Department of Crystallography and Biophysics for providing the
NMR facility and Dr S. Balakumar, National Centre for Nano-
science and Nanotechnology, University of Madras, for
providing the HRTEM facility.
Fig. 8 Log–log plot dielectric constants of BCC and BCC/FMCM-41
polymeric nanocomposites.
References
Moreover, the non-polar aliphatic chain intrinsically reduces
the dipoles between the electrodes and signicantly reduces the
dielectric constant throughout the matrix, because the reduc-
tion of polarization between the electrodes inuences the
reduction of capacitance and hence reduces the dielectric
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FMCM-41 lowers the value of dielectric constant upto 10 wt%.
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dielectrics which could contribute to power consumption in
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lowest tangent loss value of 0.0092 was observed for BCC/7%
FMCM-41 polymer nanocomposites indicating that these types
of composite materials can be employed as a potential candi-
dates for next generation microelectronics.
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57766 | RSC Adv., 2014, 4, 57759–57767
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