ac 002effect of zno nanoparticles on cure · pdf filethe most common activator is zinc oxide...

The 23rd PPC Symposium on Petroleum, Petrochemicals, and Polymers and The 8th Research Symposium on
Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 1
AC 002
EFFECT OF ZnO NANOPARTICLES ON CURE BEHAVIOR OF THE EPDM
RUBBER
Nuttiya Sa-nguansak a and Stephan Thierry Dubas*
a
a The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand
Keywords: EPDM, ZnO, Rubber
ABSTRACT
Ethylene-propylene-diene-monomer (EPDM) rubber is a synthetic rubber that has been
used in a various applications. Many rubber industries mainly use an activator, which is
commonly zinc oxide (ZnO), to promote the accelerator during the vulcanization process.
In this study the morphology, particles size, dispersion of synthesized ZnO nanoparticles in
rubber matrix, and degree of vulcanization are examined. ZnO nanoparticles are prepared
by using different concentration of alginic acid, a polyelectrolyte, as a capping agent and
the synthesized nanoparticles are later mixed into the EPDM rubber. The morphology and
properties of EPDM rubber with ZnO nanoparticles are studied by different techniques such
as scanning electron microscopy (SEM), optical microscope, X-Ray diffraction (XRD) and
moving die rheology (MDR). The results showed that the ZnO particle size is decreased
from 243 to 39 nm with increasing alginic acid concentration. The scorch time of EPDM
rubber filled synthesized ZnO using 0, 0.1, 1 and 10 mM alginic acid are not different
significantly, moreover; 10 mM alginic acid cured the slowest. Also, the MH-ML or the
torque difference of EPDM rubber with ZnO using 10 mM Alginic acid was the highest
meaning that it has the highest cross-linked density.
* [email protected]
INTRODUCTION
Ethylene-propylene-diene-monomer (EPDM) rubber is a synthetic rubber has been gaining
attention from many researchers. In recent years, EPDM has been used in a various
applications such as automobile manufacturing, external body seal, piping industries, seal
and washing machine parts due to its durability, good flexibility, fatigue resistance,
excellent electrical insulation properties, very good chemical resistance and good anti-aging
properties for heat, light, oxygen and ozone, so it is useful for outdoor applications.
However, EPDM rubber requires additives to improve the quality and reduce cost of the
products. Many rubber industries mainly use an activator to promote the accelerator for
vulcanization process. The most common activator is zinc oxide (ZnO) which can improve
the thermal conductivity of rubber, abrasion resistance, heat resistance of the valcanizates,
decrease the shrinkage of molded products. And also enhance mechanical properties.
Currently, many applications require nanoparticles for high-quality product and high
surface area. For this reason the development of, ZnO nanoparticles is interested and should
be use in rubber due to smaller size and higher surface area when compared with
mailto:[email protected]

AC 002
commercial ZnO. The ZnO nanoparticles might lead to an increase in degree of
vulcanization and an improvement mechanical properties. But there is some limitation of
commercial ZnO nanoparticle which is the expensive cost. Consequently, the objective for
this work is to synthesize ZnO nanoparticles and introduce into the rubber.
Polyelectrolyte has been used as stabilizing agent for the synthesis of a wide range of
nanoparticles including organic, inorganic carbon and metallic nanoparticles. Favorable
interactions between the charged functional group on the polyelectrolyte with the surface of
the nanoparticles are needed to insure polyelectrolyte wrapping around the nanoparticles.
In this work, ZnO nanoparticles will be prepared with polyelectrolyte as capping agent, the
parameter in this studies is type and concentration ratio of polyelectrolyte.
The purpose of this work is to achieve nano-size ZnO to fill in EPDM rubber and study the
dispersion of ZnO nanoparticles in rubber matrix, degree of vulcanization and mechanical
properties.
EXPERIMENTAL
A. Synthesis of ZnO nanoparticles
ZnO nanoparticles was synthesize by a mixer of Zn(CH3COO)2.2H2O 200 mM in 200 mL
DI water and alginic acid at different polyelectrolyte concentration in 200 mL DI water.
Add NaOH for adjust pH to 10 in mixture solution and stirred for 1 hour, get white
precipicate and filtrate them. After that, dry in oven at 100 C overnight.
B. Preparation of rubber compound
Masticate EPDM rubber 50 g in Two-roll mill for 5 min. ZnO 3 phr and stearic acid 2 phr
were added and mixed it for 7 min and then add sulfur 2 phr and TBBS (or other
accelerator) 1.5 phr until it was homogeneous (around 7 min). After that, foaming and
valcanising EPDM rubber in compression mould at 140 C for a certain time obtained
from MDR machine.
C. Characterization
The morphology of ZnO nanoparticles was characterized by using scanning electron
microscopy (SEM). The particles size by using particle size analyzer (PSA). Cure time,
cure rate, scorch time were characterized by using die rheology (MDR). The mechanical
properties were characterized by using universal testing machine (UTM). The structure of
crystalline materials was characterized by using X-Ray diffraction (XRD). The dispersion
of ZnO fill in rubber was characterized by using optical microscope.
RESULTS AND DISCUSSION
A. Synthesized ZnO nanoparticles by varies polyelectrolyte concentration
X-ray diffraction (XRD) showed clearly results to confirm that the product
from the synthesis is ZnO as shown in figure 4.1. The peak at scattering angles (2) of
31.3670, 34.0270, 35.8596, 47.1635, 56.2572, 62.5384, 67.6356, and 68.7978 correspond

AC 002
to the reflection from: 100, 002, 101, 102, 110, 103, 200, and 112 crystal planes,
respectively. The XRD pattern is indicate to the hexagonal phase with Wurtzite structure
when compared to the standard peak of ZnO.
20 40 60 80
0.0e+000
2.0e+004
4.0e+004
6.0e+004
Zn
O
Zn
O
Zn
O
Zn
O Zn
O
Zn
O
Zn
O
Na4
Zn
O3
4 H
2 O
Na4
Zn
O3
4 H
2 O
Na4
Zn
O3
4 H
2 O
Na4
Zn
O3
4 H
2 O
Na4
Zn
O3
4 H
2 O
Na4
Zn
O3
4 H
2 O
Na2
Zn
O2
2 H
2 O
Na2
Zn
O2
2 H
2 O
Na2
Zn
O2
2 H
2 O
Na2
Zn
O2
2 H
2 O
Na2
Zn
O2
2 H
2 O
Na2
Zn
O2
2 H
2 O
20 40 60 80 0.0e+000
2.0e+004
4.0e+004
6.0e+004
8.0e+004
Inte
gra
ted I
nte
nsity (
cps d
eg
)
2-theta (deg)
Inte
nsity (
cps)
Zinc Oxide, Zn O, 01-075-0576Sodium Zinc Oxide Hydrate, Na4 Zn O3 4 H2 O, 00-002-1013Sodium Zinc Oxide Hydrate, Na2 Zn O2 2 H2 O, 00-002-1014
Figure 4.1 The components of the elements was characterized by using XRD
Figure 4.2 Morphology of ZnO nanoparticles at different concentration of Alginic acid
without calcination (left side) and calcination (right side)
Alginic acid
concentration (mM)
Mean particles size (nm.)
Without calcination Calcination
0 108 98.5
0.1 173.3 (agglomerate) 69.9 (agglomerate)
1.0 103.2 68.25
10 39 37
Table 4.1 particle size of ZnO at different capping agent concentration

AC 002
From figure 4.1 shows the morphology of ZnO nanoparticles at different
concentration of alginic acid. The result shows that ZnO nanoparticles have sphere shape
and agglomerate into huge particles. The size of ZnO nanoparticles was shown in Table
4.1. At alginic acid concentration 0, 0.1, 1.0 and 10 mM , mean particles size is 108, 173.3,
103.2 and 39 nm., respectively. For ZnO nanoparticles without calcination, the result
showed that at 0 mM Alginic acid, the size of ZnO is around 108 nm and agglomerate into
big particles. At 0.1 mM alginic acid, ZnO is bigger and also agglomerate because the
amount of capping agent isnt enough to cap the Zn2+
. Therefore, it causes the ZnO
nanoparticles to stick together. At 1 mM alginic acid, the size of ZnO particles is still
bigger but it isnt agglomerate. Hence, the capping agent increases, most of Zn2+
was
capped which causes

ac 002effect of zno nanoparticles on cure · pdf filethe most common activator is zinc oxide...

Documents