NANOSCALE RUBBER REINFORCEMENTS

1
NANOSCALE RUBBER REINFORCEMENTS
Faisal M. Alyamani and Lloyd A.
Goettler Department of Polymer Engineering,
University of Akron, Polymer Engineering Academic
Center. Akron, OH 44325-0301

• OBJECTIVES
• The main objectives of this research is to
  determine- a) Layered silicate nanomorphology
  generated in SBR.
• 
  b)
  Effect of dispersing agent on nanocomposite
  formation.

ABSTRACT The strong demand for high performance
polymers has driven attention to polymer
composites in the past two decades as an
effective route to property enhancement. Typical
polymer/clay nanocomposite is composed of filler
embedded in a polymerized medium. Recently,
clay-polymer nanocomposites have become
commercially viable technological materials
because of their ability to improve material
properties in the absence of any significant
disadvantages. This research work focuses broadly
on the effect of different types of layered
silicates at different concentrations to add more
effectiveness to the properties or even a
replacement of the conventional reinforcement
fillers in styrenebutadiene-rubber, with
emphasis on variations in the mixing scheme and
addition of potential dispersion and bonding
agents to the composite formulation. Also, the
effects of both the fillers and additives on the
cure characteristics of the rubber composition
were investigated. Tensile measurements are being
carried out to observe the role of compatibility
between the filler treatment and the matrix. The
intercalation of the silicates by the polymer
molecules, leading to potential exfoliation of
the clay layers into the rubber matrix, will be
investigated using wide angle X-ray diffraction.
The main goal of this work is to produce a
rubber nanocomposite with high mechanical
properties.
EXPERIMENTAL I. Materials Elastomer -
Styrene-Butadiene-rubber 1502(23wt bound
styrene) Nanoclay - Cloisite 10A, 20A,
25A Na (Southern Clay Products)
Dispersing Agent II. Preparation
Direct melt compounding of SBR master batch with
organically treated nanoclays
curatives and organically treated nanoclays
using compatibilizers (5 Phr) carried out in a
Brabender mixer at 65 rpm and 80ºC for
10 min. III. Characterization 1. cure
characterization were done for all runs using
Alpha 2000 Rheometer at 150ºC. 2. X-ray
diffraction using a Rigaku X-ray diffractometer
with Ni filtered CuKa radiation. 3.
Tensile testing under ASTM D412 using Die type D
for specimens.
Surfactants
10A cation
20A cation
25A cation
Formulation Table
X-Ray Diffraction RESULTS FOR SBR NANOCOMPOSITES
RESULTS
TENSILE TEST RESULTS FOR SBR NANOCOMPOSITES
CURE CHARACTERIZATION FOR SBR NANOCOMPOSITES
Figure 2 Overall effect of each type of layered
silicate on the carbon filled rubber matrix with
without DA addition on the tensile strength
Modulus
Figure 4Effect of dispersing agent on nanoclay
nanocomposite
Figure 3 Overall effect of each type of layered
silicate on the Gum SBR with without DA
addition on the tensile strength Modulus

• CONCLUSIONS
• Dispersing agent affects the cure characteristics
  of the nanocomposite directly and through
  interaction with the presence of organoclay.
• Dispersing agent further enhances the tensile
  properties in the presence of nanoclay
  especially for the treated organo layered
  silicates.
• Cloisite 20A AND 25A are the best compatible
  organoclay for the SBR matrix with the presence
  of the dispersion agent.
• Based on WAXD, nanoclay interacts with the
  dispersing agent through enhanced intercalation
  of the polymer into the silicate galleries.

• FUTUR WORK
• Investigate the reactions between the disper-sion
  agent and the nanocomposite.
• Investigate the dispersion of the different types
  of layered silicates in different type of
  elastomers.

Figure 1 Effect of the DA on the cure
characteristics of the SBR nanocomposites
OCTS Workshop, Dayton, OH. MARCH 2005.