Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 1

ISSN 2229-5518

NANOKAOLIN CLAY AS REINFORCING FILLER IN NITRILE RUBBER

Preet ha Nai r K, Dr. Rani Joseph

Abstract Nanocomposites w ere prepared by incorporating varying amounts of nanokaolin clay and vinyl silane grafted nanokaolin clay in NBR, on a tw o roll mill. Improvement in mechanical properties like tensile strength, elongation at break, modulus and tear strength w er e observed f or the composites. Cure characteristics show ed an increase in the cure rate of the composites.Clay rubber nanocomposites w ere characte- rized by X- ray diff raction (XRD) and scanning electron microscopy (SEM). The increase in d spacing suggested an intercalated /exf oliated

structure of clay and SEM studies show ed unif orm dispersion of clay in the matrix. Sw elling index decreased w ith the increase in f iller loading,

as observed f rom the sw elling studies conducted in toluene. Rubber f iller interactions w ere also studied by strain sw eep analysis. It w as f ound that the complex modulus values increased w ith the clay content indicating better rubber f iller interaction.Diff erential scanning calorimetry (DSC) studies show ed that glass trasition temperature (Tg) remained unchanged. Thermal studies show ed that addition of clay marginally im- proved the thermal stability.

Inde x Terms, Cure charecterestics, Mechanical properties, Nanokaolin clay, Nitrile butadiene rubber, Vinyl silane graf ted nanokaolin clay, Scanning electro microscopy, Thermo gravimetric analysis.

—————————— ——————————

1 INTRODUCTION

Remarkable enhancement in the properties of polymers are ob- served on incorporation of nanofillers . With the advent of p o- lymer nanocomposites by the Toyota group of companies, con- ventional fillers gave way to nano fillers. Among the nanofil- lers, nanoclays occupy the prime position. Now polymer clay nanocomposites (PCNs) have become one of the most promis- ing research areas in the field of polymer science and technol o- gy. Use of clay in thermoplastics like polypropylene [1],[2],[3] polystyrene [4] etc. are widely studied. Recently rubber/clay nanocomposites[5],[6],[7] have also received special attention.
. Filler reinforcement is more pronounced with non crystal- lising synthetic rubbers like NBR and SBR compared to NR which undergoes crystallization on stretching. In rubber rein- forcement, the most important characteristic of the reinforcing filler is its small size, so that the particles have a large surface area to interact with rubber. In addition to particle size, particle structure also influence its reinforcing efficiency[8] . Among the various nano clays used the 2:1, expanding type, clay min- eral , montmorillonite takes prime position. Polymer clay nan o- composites derived from organically modified MMT has been extensively studied as shown by a large number of publications on the subject.[9],[10].[11],[12],[13],[14],[15],[16],[`17].

.

———— ——— ——— ——— ———

Preetha Nair K is currently pursuing research in the Department of Polymer Science and Rubber Technology ,Cochin University of Science and Technolo- gy,Cochin ,Kerala, PH-9447390769 E-mail: preethaknair@gmail.com

Dr Rani Joseph is Professor, Department of Polymer Science and Rubber Tech-

nology,Cochin University of ScienceandTechnology,Email:rani@cusat.ac.in
However kaolin (Al2[Si2O5](OH)4) is a 1:1 non expanding type clay with neither cations nor anions in the interlayer re- gion. Modified nano kaolin is used in natural rubber [18] sty- rene butadiene rubber [19] and epoxidized natural rubber [.20] Kaolin can provide excellent reinforcement in rubber. Q Liu[21] has compared pricipitated silica (PS) and nanokaolin clay (NK) in different matrices and has found that the mechanical proper- ties like tensile strength, elongation at break and rebound elas- ticity are superior to PS.
Until now little study has been taken up with kaolin clay.
Kaolin is very low cost, non swellable, easily available clay. In this work we report the effect of addition of unmodified and modified kaolin clay on the mechanical properties of NBR.
.

2 EXP ERIM ENTAL

2.1 Materials

Acrylo nitrile butadiene rubber grade-KNB 35L, Nanokaolin clay (Nano Caliber 100) and vinyl silane grafted nano kaolin clay (Nano Caliber 100V) are supplied by English Indian Clays Ltd. (Thiruvananthapuram). Zinc oxide (ZnO), Sulphur (S), N-Cyclohexyl-2benzothiazole sulfenamide (CBS), Tetra methyl thiuram disulphide (TMTD), Stearic acid, antioxidant HS used were of commercial grade.

.

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 2

ISSN 2229-5518

2.2 Preparation of NBR clay compound s

Compounding of NBR was done on a two roll mi ll as per the formulation given in Table1.NBR was masticated for 2 mts on a two roll mill (6 x 12‖) and the ingredients were added in the same order as mentioned. Unmodified clay (Nano Cal iber 100) is represented as C and modified clay (Nano Caliber 100V) as V.The composites are designated as NBR C and NBR V com- pounds.Cocentration of filler is also given along with the name of the compound. C and V were added in varying con- centration(inparts per hundred rubber,phr) .The samples were then cured at 1000C in an electrically heated hydraulic press to their respective optimum cure time at a pressure of 150
Kg/cm2in a specially designed mould to get sample sheets having thickness 1.5 mm approximately.
Table1
Formulation of NBR clay composite

INGREDIENTS

WEIGHT (g)

NBR

100

S

1.5

ZnO

4.5

Stearic acid

2.0

Clay

Varying concentration

HS

1

CBS

1

TMTD

0.25

2. 3.Cure characteresti cs

Cure charecterestics of clay filled NBR was studied using a
Rubber Process Analyzer (RPA2000) as per ASTM standard D
2084-01 .Important parameter like maximum torque Dmax, minimum torque Dmin, cure time T90, Scorch time T10 were determined. Cure rate index which is a measure of the rate of cure reaction is given by CRI = 100/ T90-T10

2.4 Mechanical properties

Dumb-bell shaped specimens were cut from the cured latex sheets and tensile strength, elongation at break and modulus, were determined on a Shimadzu Un iversal Testing Machine (AG1 series),using a cross head speed of 500mm/min as per ASTM D 412-1998. All the tests were carried out at 28+/-
20C.Five samples were tested and their average values were
taken.
Tear resistance was also carried out on a Shimadzu Auto- graph AG1 series Universal testing machine UTM ,using a cross head speed of 500mm/min at test temperature 28+/-
20C as per ASTM D 624 -1998. The tear resistances of the samples were reported in N/mm

2.5 Swelling studie s:

Solvent swelling of cured rubber compounds was car ried out in toluene. Samples were weighed (w1) before immersion at
250C. After 24 hrs when equilibrium swelling was reached, the
swollen samples were removed, wiped dry and again weighed (w2). The degree of swelling was calculated using the follow ing equation. Swelling index (100%) = w2 - w1/ w1x100

2.4 X ray Dffraction Studies (X RD)

For characterization of clays and rubber composites XRD stu- dies were conducted by Bruker, D8 advance model employing CuKα radiation λ=1.54A0 X-ray diffraction method gives qualitative information about the exfoliation and d spacing of clay layers in the polymer matrix compared to that of pure clay. When polymer chains are inserted in the gallery spacing of the clay layers, the interlayer spacing increases and the shifting of diffraction peaks to lower angle takes place. Di f- fraction peaks disappear for exfoliated structures, where sil i- cate layers are completely and uniformly dispersed in the ma- trix

2.6 Scanning Electron Micr o scopy (S EM)

The morphology of the nanocomposites was studied using
Joel Model JSM 6390LV Scanning electron microscope.

2.7 Strain Sweep Studies

The strain sweep studies at low strain amplitude were con- ducted on RPA. It gives information about the dispersion of filler particles in rubber matrix. The variation of storage mod- ulus G, loss modulus G/ and complex modulus G* with change in strain amplitude can be measured on RPA

2.8 Differential Scanning Calorimetric Analysi s (DS C):

To analyze the effect of clay on the glass transition tempera-
ture of NBR, DSC scan was performed. DSC measurements
were performed at a temperature range of -600 C to 900C. In the case of polymer nanocomposites DSC measurements are useful for the identification of the extent of intercalation or exfoliation of the nanopa rticles in the matrix.

2.9 Thermo Gravimetric Analysi s (T GA)

Thermal degradation studies involve the measurement of
change in the weight of the material as a result of heating in an inert atmosphere. The integral (TGA) and derivative (DTG) thermogravimetric curves provide information about the thermal stability and extent of degradation of polymeric mate- rials.

3. RES ULTS AND DISCUSSION

3.1Cure characteristics

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 3

ISSN 2229-5518

Cure characteristics of NBR-C and NBR-V composites ex- pressed in terms of optimum cure time (T90), scorchtime (T10), and cure rate index CRI and the difference in maximum and minimum torque values (Dmax-Dmin) are given in tables 2 and 3 respectively.
Table2
Cure Charecterestics of NBR C composite
Acidic nature of Clay activates the formation of s oluble Zn ions and the Zn ions might have promoted the formation of free radicals by the accelerator in the early stages of the cross linking reaction. These free radicals can cause premature vul- canization resulting in a decrease in scorch time [22].
From the cure time values it is seen that NBR V composites accelerates curing reaction when compared to NBR C compo- sites. Cure retardation in NBR C composites may be due to the absorption of curatives by the unmodified clay which will reduce the amount of curatives available for cure rea c- tion.Higher CRI values of NBR V composites show that the unsaturated sites of vinyl group may get cross linked with that of NBR in the vulcanization. The favorable entrapment of rub- ber, curatives and vinyl modifier within the intercalated sil i- cate galleries might be the reason for the accelerating effect of modified clay on curing [23]
Slight increase in torque values suggests an increase in cross linking density in the rubber phase. Swelling studies also con- firm an increase in cross link density with the increase in the concentration of clay.

3.2Cure Kinetics:

The plots of log (Dmax-Dt) against time for NBR C andNBR V composites are given in Fig: 3 and 4 respectively Dmax is the maximum torque and Dt is the torque at a given time.
The plots are found to be linear which proves the cure rea ction proceeds according to the first order kinetics.

-0.2

Table3
Cure Charecterestics of NBR V composite

-0.4

-0.6

-0.8

-1.0

c0 c1 c10 c20

-1.2

-1.4

-1.6

5 6 7 8 9 10

TIME (min)

(a)
Addition of C and V in NBR shows a small reduction in scorch time and cure time of the composites. Torque values (Dmax- Dmin) of the composites show a slight increase and CRI va l-

0.0

-0.1

-0.2

-0.3

-0.4

-0.5

-0.6

-0.7

-0.8

-0.9

-1.0

-1.1

-1.2

-1.3

-1.4

-1.5

-1.6

v0 v1 v5 v10 v15


ues of the composites show considerable increase with the
addition of clay.

4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0

TIME (min)

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 4

ISSN 2229-5518

(b)
Fig: 1: Plot of log Dmax-Dt against time for
(a)
NBR C Com- posite
and (b)

6.4

6.2

6.0

5.8

5.6

5.4

5.2

5.0

4.8

4.6

4.4

4.2

4.0

3.8

TENSILE STRENGTH

V C

composite

3.3 Mechanical properties:

NBR V

0 2 4 6 8 10 12 14 16 18 20 22

CONCENTRATION OF CLAY (phr)

Fig:2
Table4
Variation in mechanical properties of NBR clay composites

1040

1000

960

ELONGATION AT BREAK

V C

920

880

840

800

760

0 2 4 6 8 10 12 14 16 18 20 22

CONCENTRATION OF CLAY (phr)

Maximum increase in mechanical properties of both the com- posites is given in Table 4.
Tensile strength, elongation at break, modulus and tear strength are maximum for unmodified clay composite at 15 phr. But modified clay composite gives maximum values of tensile strength and elongation at break at a lower concentra tion of 5 phr.
Here unmodified clay is hydrophilic and on organic modifica- tion it becomes hydrophobic. Hydrophobic clay is more com- patible with NBR.
Variation of tensile strength and elongation at break of NBR C and NBR V composite is as shown in Fig 2 and 3 respectively. Both the values increases with clay loading, reaches a maxi- mum and then decreases. For NBR V composite tensile strength and elongation at break increases up to 5 phr (32% and 13% respectively) and then decreases. But for NBR -C composite tensile strength and elongation at break reaches a maximum (57% and 30% respectively) only at 15 phr.
Fig: 3
The increase in tensile strength may be due to the increase in interfacial area of clay platelets and good interaction between the clay platelets and NBR. Increase in interfacial area arises
by intercalation or possible exfoliation of clay layers, as evi-
denced by XRD analysis. In kaolin clay the layers are linked through Hydrogen bonding between hydroxyl groups on the octahedral sheet and oxide arrangement of tetrahedral sheet. Even though the intercalation rea ctivity of kaolin is low due to hydrogen bonding between the layers, the free OH groups on kaolin can interact with the CN groups of NBR .In vinyl mod- ified clay the vinyl groups on the surface of kaolin clay forms
a bridging cross linking reaction with rubber when cured, thus giving reinforcement in properties.Decrease in tensile strength at higher loading may be due to agglomeration of clay tacto- ids.
Generally rigid fillers cause a significant reduction in elonga- tion at break, but the presence of clay improves the elongation at break more than with other isotropic fillers. Better filler dispersion and strong rubber filler interaction leads to an in-

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 5

ISSN 2229-5518

crease in elongation values.SEM images of the composites show a good dispersion of filler in NBR. When rubber filler interaction increases, rubber absorbs more energy, decoils the chain to a greater extent, leading to a chain slippage over the longer clay particles. At higher loading the elongation at break decreases because of filler aggregation. Aggregation of filler weakens the number of available reinforcing links [ 24]. The formation of non exfoliated aggregates at higher clay content makes these composites much more brittle.
Variation of modulus at 300% elongation of NBR C and V composites are shown in Fig4. Modulus of NBR- C composite increasesupto 5phr and then remains a constant. While the modulus of NBR- V composite increases continuously with the increase in clay content. Better compatibility of modified clay and the cross linking of the vinyl group with the matrix may
be the reason for this behaviour. Also n anometric dispersion of clay layers gives sufficient reinforcement leading to im- proved stiffness.

TEAR STRENGTH

24 V C

23

22

21

20

19

18

17

16

15

0 5 10 15

CONCENTRATION OF CLAY (phr)

Fig: 5

2.4

2.3

2.2

MODULUS AT 300% ELONGATION

V C

Swelling studies show that the swelling index of both clay composites decreases with the addition of clay as shown in Fig: 6. The extent of cross linking is inversely proportional to the swelling index. The gum has the maximum toluene uptake at equilibrium swelling, showing that there is no restriction for toluene penetration .When the clay loading increases the sol- vent uptake is restricted due to the increased cross linking.

2.1

2.0

1.9

0 2 4 6 8 10 12 14 16 18 20 22

CONCENTRATION OF CLAY (phr)

Fig: 4

190

188

186

184

182

180

178

176

174

172

SWELLING INDEX

C V

Tear strength of NBR C and V composites increases with the clay loading as seen in fig 5. Tear strength is greater for the unmodified clay composite. The dispersed c lay layers and small tactoids act as a barrier for crack propogation during the tear process thus increasing the tear strength.

170

168

0 2 4 6 8 10 12 14 16

CONCENTRATION OF CLAY (phr)

Fig:6
3. 4 XRD analysis: XRD patterns of clay and its composites are given in fig 7 The charecterestic peaks of kaolin are seen around 2θ =120, 200 and 25.0which are assigned to the interla y- er spacing of 7.12, 4.41 and 3.56A0 respectively.

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 6

ISSN 2229-5518

100

80

60

40

20

0

d=7.11

d=3.56

V NBR V

modified MMT nanocomposite a decrease in d spacing after curing was observed [25]. For NBR /Na- MMT composite a peak appeared with a decrease in intensity compared to pris- tine Na MMT [24]. S.Sadhu and A K Bhowmick [27] have dealt with unmodified MMT on SBR with varying styrene content and using dicumyl peroxide as the curing agent and suggested that exfoliation has taken place in all the composites

3 .5 SEM ANALYSIS:

Fig 8 and 9 are the SEM images of the tear fractured surfaces
of NBR C and NBR V composites. A uniform distribution of

9 12 15 18 21 24 27 30

2 THETA(Degree)

(a)
clay particles is seen in both images. The tear pattern of NBR V composite shows a series of tear ridges parallel to the tea ring direction.

100

80

60

40

20

0

d=7.11

C

d=4.41

d=3.56

NBR C

9 12 15 18 21 24 27 30

2THETA(Degree)

(b)
Fig: 7 XRD of (a) NBR Vand (b) NBR C composites
XRD peak at 120 shows a shift to a lower angle in both the composites.The shift is greater for NBR C composite. Shift to lower angle indicates intercalation of NBR into the clay galle- ries.The increase in d spacing after curing may be due to the increase in the mobility of clay and polymer chains at the moulding temperature and pressure [25]. A small reduction in the intensity of the peak shows a disordered intercalated structure and exfoliation of some organic clay in the nano- composite. The disappearance of the peaks between 13 0 and
250in the composites show that exfoliation has taken place to some extent. Additional peaks at higher 2 theta for both the composites indicate the collapse of some intercalated struc- ture. In the melt blended system part of the intercalated clay must have been squeezed out from the layer giving rise to some clay aggregates [25].
These observations are common in literature where MMT is used as the reinforcing filler. Amit et al [26] have worked on carboxylated NBR / Organomodified MMTcomposites and has shown that the intercalation is a common process from 2.5 to 10 phr organo clay mixed at 160 0C. In an NBR- organically

Fig:8

SEM of NBR C composite
Fig:9
SEM of NBR V composite

3.6 STRAIN SWEEP STUDIES

Fig: 10 (a) and (b) shows the variation of complex modulus of the uncured NBR C and NBR V composite respectively with the strain amplitude. Strain sweep studies were conducted to study the rubber filler interaction. Complex modulus values decreased with the increase in strain. This is because forma- tion of filler net work contributes to the reinforcement in the properties of rubber. At high filler loading a gglomeration of filler particles takes place leading to chain like filler structures or clusters which are termed filler networks. In kaolin compo- sites besides the confinement of the polymer chains between

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 7

ISSN 2229-5518

the silicate layers there is polar interac- tion betwee the OH group of the clay and CN group of the ni- trile rubber.With the increase in strain,the filler networking is destructed leading to
tures of NBR and its composites are almost the same.So the mobility of the polymer chains are not a ffected by the clay layers Table: 5

Tg of NBR and NBR clay composites
a reduction in complex modulus.
The complex modulus values at low strain increased with

Na me T0 Tma x Res idue

%

T5 T50

filler concentration. The enhancement of modulus with clay
content is an indication of better filler-rubber interactions and hydrodynamic effect.
The increase in modulus is due to the inclusion of rigid filler

0.0

NBR 340.36 456 6.783 322.03 444.79

NBR 5c 341.44 456 1N5B.4R5 319.15 448.63

NBR V

particles in the soft rubber matrix. At low strain although both

-0.1

NBR15c 340.90 458 1N6B.6R9C

318.60 451.77

the clay rubber interaction and the compatibility between the
clay and NBR are weak the filler -filler interaction is very
strong due to filler aggregates

-0.2

NBR 7v 339.12 456 12.98 304.64 448.18

NBR15v 340.14 458 16.23 302.7 451.04

110

105

100

95

90

85

80

75

70

65

60

c0 c1 c5 c10 c15

-0.3

-0.4

-20 0 20 40 60 80 100

TEMPERATURE(0C)

Fig: 11
DSC curves of NBR, NBR C and NBR V

115

110

105

100

10 20 30 40

STRAIN%


(a)

v0 v5 v10 v15

3.7Thermo gravimetric analysis

The thermal properties of the NBR Composites were studied
by thermo gravimetric analysis. Table (6) shows the thermal degradation data for pure NBR and its composites.
T able: 6
TGA results of NBR andNBR clay composites

95

90

85

80

10 20 30 40

STRAIN%

(b)
Fig:10 Variation of storage modulus with strain% of (a)NBR
C composite and (b) NBR V composite.

3.7 DSC STUDIES:

. DSC thermograms for NBR, NBR C and NBR V composites are shown in Fig: 11and the corresponding Tgs are summa- rized in Table: 5. It is seen that the glass transition tempera-
At lower temperature there is no considerable change in the behavior of pure NBR and the composites. Onset of degrada-

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 8

ISSN 2229-5518

tion starts around 3400C for all the vulcanizates. Hence the samples may be considered thermally stable upto340 0C in ni- trogen atmosphere.
The degradation temperature at 5% weight loss (T5) decrea ses with the addition of clay. NBR V composite shows greater reduction in T5 values than the unmodified clay. This shows the decomposition of vinyl chains cause faster degradation for the modified composites. Degradation temperature at 50% weight loss (T50) follows the same trend for NBR C and NBR V composites. Composites give higher value of T50 than that of pure NBR. This shows the thermal stability of NBR has i m- proved by the presence of intercalated/exfoliated clay at tem- peratures above 4000C.
DTG curves are shown in Fig 17 (a&b). DTG curves show that the pyrolysis of NBR takes place in two steps. The curve exh i- bits a shoulder at 4280C followed by a main peak with a ma x- imum at 4560C. The peak of the DTG curves shows the tem- perature corresponding to maximum degradation. The ther- mal degradation of rubber results in th e scission of cross link- ing network and chain cleavage and a reduction in molecular weight

1.4

.Fig:12: DTG curves of (a) pure NBR and NBR C composite
(b) pure NBR and NBR V composite
This reduces the mechanical strength and application value of rubber. It is generally believed that the inclusion of inorganic components into organic matter can improve the thermal sta- bility. Maximum degradation temperature slightly i ncreased from 456 to 458 in both the composites at 15 phr. So the com- posites have the same thermal stability. It is also observed that the amount of residue increases with the increase in clay con- tent. The residual materials are mainly due to Zn salts and inorganic fillers.

4 CONCLUSIONS

Improvement in mechanical properties of the composites re- veal that both unmodified and modified nanokaolin clay can be used as reinforcing filler in NBR.Modified clay is found to be a better reinforcing filler compared to unmodified clay..
The cure rate is increased with the addition of both clays..
The XRD charecterisation of the composites show par- tial intercalation, but the increase in gallery gap may not be sufficient for the rubber molecules to have a strong interaction with the clay as observed from DSC analysis.The strain sweep

1.2

1.0

0.8

0.6

0.4

0.2

0.0

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

nbr

nbr 5c nbr 15c

0 100 200 300 400 500 600 700 800

TEMPERATURE (0C)


(a)

nbr

nbr 5v nbr 15v

0 100 200 300 400 500 600 700 800

TEMPERATURE (0C)

(b)
studies shows better polymer filler interaction and SEM anal y-
sis shows a uniform dispersion of clay in the matrix. There is a small increase in the thermal stability of the system as ob- served from TGA.
.REFEREN CES

[1] Masaya Kawasumi, Naoki Hasegawa, Makoto Kato, Arimitsu Usuki, and Akane Okada,‖.Preparation and Mechanical Properties of Polypropylene−Clay Hybrids‖, Macromolecules, 1997, 30 (20), pp

6333–6338

[2] Jeong Hyun Parka, Hyung Min Leea, In-Joo China, Hyoung Jin Choia

―Intercalated Polypropylene/Clay nanocomposite and its Physical Cha racteristics‖,Journal of Physics and Chemistry of Solids

Volume 69, Issues 5-6, May-June 2008, Pages 1375-1378

14th International Symposium on Intercalation Compounds

[3] Jian Li, Cixing Zhou, Gang Wang, Delu Zhao,Study on Rheological Behavior of Polypropylene/Clay Nanocomposites‖ Journal of Applied Polymer Science, Vol. 89, 3609–3617 (2003)

[4] Periyayya Uthirakumar, Min-Ki Song, Changwoon Nah, Youn

Sik Lee‖ Preparation and Characterization of Exfoliated P olystyrene/ Clay nanocomposites using a Cationic Radical I nitiator-MMT Hybrid‖ EuropeanPolymerJournalVolume 41, Issue 2, February 2005, Pages

211-217

[5] Qing-Xiu Jia , You-Ping Wub , Yi-Qing Wang , Ming Lu , Li-Qun

Zhang,‖ Enhanced Iinterfacial Iinteraction of Rubber/Clay nanocom po sites bya Novel Two-Step Method‖Composites Science and Technol gy 68 (2008) 1050–1056

[6] Wonho Kim, Byung-Suk kang, Seong-Gyucho, Chang-Sikha and Jong-

IJSER © 2012

http :// www.ijser.org

Inte rnatio nal Jo urnal o f Sc ie ntific & Eng inee ring Re se arc h Vo lume 3, Issue 3 , Marc h -2012 9

ISSN 2229-5518

Woo bae, ―Styrene butadiene Rubber-Clay nanocomposites using a Latex MethodMorphology and Mechanical Proper ties‖ Composite Interfaces, Vol. 14, No. 5-6, pp. 409–425 (2007)

[7]Anirbanganguly, Madhuchhandamaiti and Anil K Bhowmick

Structure–Property Relationship of Specialty Elastomer–

Clay nanocomposites Bull. Mater. Sci., Vol. 31, No. 3, June 2008, pp.

455–459

[8] Renukap p a, R.D, Sudhaker, S.J, ―Studies on Phy sicomechanical and Electrical Prop erties of SBR-C black comp osites‖, Journal of Rein forced Plastics and Comp osites, August (2006)Vol25 no:11 1173

[9] Yu-Rong Liang, Wei-Liang Cao, Xiao-Bin Zhang, Ying-Jie Tan, Shao-JianHe, Li-Qun Zhang‖, Prep aration and Prop erties of Nanocomp osites Based on Different Polarities of Nitrile–Butadiene Rubber with Clay ‖, Journal ofApp lied Poly mer Science, Vol. 112,

3087–3094 (2009).

[10] Jin-tae Kim, Taeg-su Oh and Don g-ho Lee,‖ Prep aration and Cha racteristics of Nitrile Rubber (NBR)Nanocomp ositesBased on Organop hilic Lay ered Clay,‖ Poly mer International Poly m Int

52:1058–1063 (2003)

[11] Jae Woo Chung, Seok Jong Han, Seung-Yeop Kwak, ―Application of strain–time correspondence as a tool for structural analysis

of acrylonitrile–butadiene copolymer na nocomposites with vari

ous organoclay loading,‖European Polymer Journal 45 (2009) 79–87

[12] Seyed Javad Ahmadi ,Christian G‘Sell, Yudong Huang, Nanqi Ren, Ahmad Mohaddespour Jean-Marie Hiver,‖Mechanical Properties of NBR/Clay nanocomposites by using a novel

testing system‖ Composites Science and Technology 69 (2009) 2566–2572

[13] Bluma G. Soares, Marlucy de Oliveira, Soraia Zaioncz, Ana

C. O. Gomes, Adria na A. Silva, Kelly S. Santos, Raquel S. Mauler Nitrile Rubber/Organomontmorillonite Nanocomposites Produced by Solution and Melt Compounding: Effect of the Polarity of the Quaternary Ammonium Intercalants , Journal of Applied Polymer

‗ Science, Vol. 119, 505–514 (2011)

[14] Meera Balachandran a, Sriram Devanathan a , R. Muraleekrishnan S.S. Bhagawan,‖ OptimizingProperties of NanoclayNitrileRubber (NBR)Composites using Facce Centred Central Composite Design Materials and Design xxx (2011) xxx–xxx

[15]Lan Liu, Demin Jia, Yuanfang Luo, Baochun Guo,‖ Preparation, Structure and Properties of Nitrile–Butadiene Rubber– Organo clay Nanocomposites by Reactive Mixing Intercalation Method,‖ Journal of Applied Polymer Science, Vol. 100, 1905–1913 (2006)

[16] Rajesh Chowdhury‖, Electron-Beam-Induced Crosslinking of

Natural Rubber/Acrylonitrile–Butadiene Rubber Latex Blends

in the Presence of Ethoxylated Pentaerythritol Tetraacrylate Used

as a Crosslinking Promoter,‖ Journal of App lied Poly mer

Science, Vol. 103, 1206–1214 (2007)

[17] Lan Liu, Yuanfang Luo, Demin Jia, WeiwenFu and Baochun Guo ―Structure and Properties of Natural Rubber Or ganoclay Nanocomposites Prepared by Grafting and–

Intercalating Method in Latex,‖ Journal of Elastomers and Plas tics, Vol. 38–April 2006

[18] Rugmini sukumar, ARR Menon,‖ Organomodified Kaolin asa

Re inforcing Filler for Natural Rubber‖, Journal of Applied Poly

‗ mer Science, Vol Vol107,3476-3483 (2008)

[19] M. Sh. Zoromba and A. A. M. Belal, A. E. M. Ali

F. M. Helaly, A. A. Abd El-Hakim, and A. S. Badran, ―Preparation

and Characterization of Some NR and SBR Formulations Contain ing Different Modified Kaolinite,‖Polymer-Plastics Technology and Engineering, 46: 529–535, 2007

[20] A K Manna,D K Tripathy, P P De,S K De M K Chatterjee,D G Peifer

, Bonding between Epoxidized Natural Rubber and Clay in Presence of silane coupling agent,‖ Journal of App lied Poly merScience vol

72, 1895-1903 (1999)

[21] Qinfu Liu, Yude Zhang, Hongliang Xu,‖ Properties of Vulcanized Rubber Nanocomposites Filled with Nanokaolin and Precipitated Silica,‖ Applied Clay Science 42 (2008) 232 -237

[22] A Shojaeia and M. Faghihia ,‖ Analysis of Structure–Properties Rela tionship in Nitrile-Butadiene Rubber/Phenolic Resin /Organoclay Ternary Nanocomposites Using Simple Model System, Polym.

Adv Technol. 2010, 21 356–364

[23] Mithun Bhattacharya, Anil K Bhowmick, ―Correlation ofVulcaniza tion andViscoelasticProperties ofNanocompositesBased onNatural Rubber and DifferentNanofillers, withMolecular and Supramole cular Structure,‖ Rubber chemistry and technology Jan-March2010 vol 83 No:1

[24] Kader, M.A.,.Kim.K.,Lee.Y.S,.NahC,‖ PreparationandProper

ties ofNitrile rubber/MontmorilloniteNanocomposites via latexBlending‖ ,J Mater Sci (2006)41:7341-7352

[25] Dongcheol Choi, M. Abdul Kader, Baik-Hwan Cho, Yang-

il Huh, Changwoon Nah, ―Vulcanization Kinetics of Nitrile

rubber/Layered Clay na nocomposites‖ Journal of Applied Poly

‗ mer Science) Volume 98,Issue 4,pages 1688 -1696 ,15 November2005

[26] AmitDas, Rene‘ Jurk, Klaus Werner Stockelhuber, Papiya Sen Ma jumder,Thomas Engelhardt, Juliane Fritzsche, Manfred Klu¨ppel and GertHeinrich,‖Processing and Properties of Nanocomposites Based on Layered Silicate and Carboxylated Nitrile Rubber‖ Jou r

nal of Macromolecular Science Part A: Pure and Applied Chemistry

(2009) 46, 7–15

[27] Susmitha Sadhu, A nil K Bhowmick,―Preparation and Properties of Nanocomposites based on Acrylontrile -Butadiene Rubber ,Styrene -Buta dene Rubber,and Poly butadiene RubberJournal ofPolymer Science Part B:Polymer Physics ,vol.42,1573 -1585 (2004)

IJSER © 2012

http :// www.ijser.org

International Jotunal of Scientific & Ergineerirrg Research Volume 3, IsseE 3, March -2012 10

ISSN 2229-5518

IJSER © 201 2

http:1/W t>NV.i jser _crg