88 Tyre Asia February/March 2018
TechnoTeS
By Arup K.Chandra & PK Mohamed
([email protected]; [email protected])
Global R&D Centre-Asia, Apollo Tyres, IndiaDr Arup Chandra P K MohamedAn overview on
innovation in tyre
Synthetic alternatives
Synthetic poly isoprene which has the structure and
properties of nR has been an important elastomer
ever since it was first discovered in 1954 with the then
newly discovered Ziegler catalyst. Although it still
demonstrates lower green strength, slower cure rates,
lower hot tear, and lower aged properties than its
natural counterpart, synthetic poly isoprene exceeds
the natural types in consistency of product, cure rate,
processing, and purity. In addition, it is superior in
mixing, extrusion, moulding, and calendering processes.
Isoprene is found in products ranging from surgical
gloves to car tyres.efforts to produce synthetic isoprene from bio-resources
commenced in the backdrop of depletion of global
petroleum resources and environmental hazards as
mentioned earlier. The production of isoprene from
renewable resources (BioIsoprene™) is the target of
a joint venture between Goodyear Tire and Rubber
company and the biotechnology company Genencor.
Using Bio Isoprene™ from Genencor, Goodyear has
produced a synthetic rubber for incorporation in a
concept tyre demonstrating the equivalence of Bio
Isoprene™ with petroleum derived isoprene. Recently,
Amyris has signed a deal with Michelin to collaborate in
the development and commercialization of Amyris no
compromise® renewable isoprene.
Amyris is also collaborating with Kuraray & Kuraray
in a venture to use Biofene to replace petroleum-
derived feedstock such as butadiene and isoprene in
the production of specified classes of high-performing
polymers.
Let’s keep our fingers crossed to see whether the joint
effort of scientists and technologists will result in
harnessing these alternatives commercially or not.General purpose rubbers
Styrene Butadiene Rubber (SBR ), among the available
synthetic rubbers, possesses the greatest balance of
functional qualities in the widest range of applications.
Solution SBR will widely replace emulsion SBR,
especially in passenger radial tyre. Solution SBR has
no organic fatty acid and has more control on micro
structure, prepared by using Ziegler-natta catalyst. This
results in better physical properties like lower rolling
resistance and better wet grip that are more stringent
requirement of ultra high performance tyre.
Butadiene Rubber (BR) prepared using neodymium
catalyst has a very high cis content, very high molecular
weight, and narrow molecular weight distribution. This
polymer exhibits better physical properties and higher
abrasion resistance, but difficult to process.
Recently, Bridgestone corporation has announced the
development of a synthetic technology that chemically
bonds a high cis-butadiene rubber (cis-BR) with silica at
its molecular chain end, resulting in a better performing,
more abrasion-resistant tyre. Bridgestone has generated
two technologies that when integrated lead to the
development of the end-functionalized high cis-BR with
reactivity to silica.
This first creates a polymer chain of high cis-BR
with an active site at chain end by redeveloping the
polymerization catalyst, which converts monomer
molecular chain to a polymer chain. The second relates
to the chemical conversion of the chain-end active site
to the silica-reactive functionality, by reaction with a
carefully designed functionalizing agent.
Bridgestone has said that if the new compound,
nanostructure-oriented properties control technology,
is used in tyre tread, it would improve flexibility in cold
conditions yet retain stiffness for warm conditions.