Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

Thermoplastic Elastomers

No description
by

Ecem Pınar Kaya

on 27 April 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Thermoplastic Elastomers

What we will see in the presentation...
Raw materials
Product
Production Methods
Industry Relation
Sustainability
Processes In Polymer Technologies

Thermoplastic Elastomers, TPE


Nihat Karakazan
Ecem Pınar Kaya
Gizem Civan
Sarka Holoubkova


April 28, 2014
Raw Materials / Additional Components
Fillers, plasticizers and oils are usually added to the TPE formulations.
Carbon black is often used to increase hardness, ultimate tensile modulus and tensile set.
Some ester-type plasticizers can also be included to improve properties at low temperature or to lower the final product Tg.
Product / TPE
Thermoplastic elastomers
are known as two-phase system consisting of rubbery elastomeric (
soft
) component and rigid (
hard
) component.
The soft phase can be;
polybutadiene, polyisobutylene, poly(ester), etc.
The hard phase can be;
polystyrene, urethane, ethylene propylene diene monomer (EPDM), and fluropolymers, etc.

Thermoplastic Elastomers, TPEs
Briefly,

Thermoplastic elastomers (TPEs) belong to a class of materials that have the combined physical properties of
thermoplastics
and
elastomers
.

They exhibit properties typical of rubbery materials but can be processed like thermoplastics.

There are six main thermoplastic elastomer groups found commercially; styrenic block copolymers (
TPE-s
), polyolefin blends (
TPE-o
), elastomeric alloys (
TPE-v or TPV
), thermoplastic polyurethanes (
TPU
), thermoplastic co-polyesters and thermoplastic polyamides.
Raw Materials / Elastomer
An elastomer
is a polymer with viscoelasticity, generally having low Young's modulus and high failure strain compared with other materials.
They will undergo an immediate, linear and reversible response to high strain to an applied force.

Some examples;

Polybutadiene


EPM (Ethylene propylene rubber)

Raw Materials / Thermoplastic
Most thermoplastics have a high molecular weight.
Some thermoplastics do not fully crystallize above glass transition temperature Tg.
Brittleness can be decreased with the addition of plasticizers.
Amorphous and semi-amorphous plastics are used when high optical clarity is necessary.

PE PP PS PVC
Product / TPEs Properties
TPEs are processed as thermoplastics
According to the volume fraction of elastomer; their properties can be optimized according to their application.
They have all the same features as described for an elastomer except that chemical cross-linking is replaced by a network of physical cross-links.
TPEs give better material utilization because scrap and rejects can be recycled.
Often, the phases are bonded chemically by block or graft polymerization.
The hard phase gives these TPEs their strength and represents the physical crosslinks.
On the other hand, the elastomer phase provides flexibility and elasticity to the system.
Product / Thermodynamic Behavior of TPE
If a gas is compressed its temperature will increase, while if an elastomer is stretched its temperature will increase.

Temperature volume and length relationship for a gas and elastomer [Elias, H.G., 2008].
Product / Tg and Tm of Some Elastomers
Thermoplastic elastomers have two service temperatures. The lower service temperature depends on the Tg of the elastomer phase, whereas the upper service temperature depends on the Tg or Tm of the hard phase.
Glass Transition and Crystal Melting Temperatures of Some Elastomers [Holden, G., 2010].
Production Methods
Elastomers are mainly synthesized using chain growth polymerization because high molar mass is a feature of this mechanism and high molar mass is required for high chain extension.

TPEs are two phase polymers, however they can be synthesised in
one reaction step
or in
two or three steps
to create each phase separately.

One-step method
is a commonly used industrial technique to prepare polyurethanes. The urethane reaction involves a diisocyanate (hard segment) and a diol (soft segment)
Schematic representation of TPUs composed of alternating hard segment and soft segment structures [Shanks and Kong., 2012].
Production Methods / Comparison of Methods
The structural regularity leads to a better packing of hard segments where physical cross-linking points are easier to form. Hence, a two-step method gives a product of better mechanical properties than a one-step method.
Comparison of properties of TPUs made from one-step and prepolymer methods [Shanks and Kong., 2012]
Production Methods / Processing Methods
The two most important manufacturing methods with TPEs are
extrusion
and
injection molding
.
Compression molding
is seldom, if ever, used. Fabrication via injection molding is extremely rapid and highly economical.
Both the equipment and methods normally used for the extrusion or injection molding of a conventional thermoplastic are generally suitable for TPEs.
TPEs can also be processed by
blow molding
,
thermoforming
, and
heat welding.
Production Methods / Typical Set-up Production
Industry Relation / Economy
For both economical and ecological reasons the replacement of virgin components of TPEs (fully or partly) by recycled polymers is very important.
Many thermoplastic elastomers (TPE) are widely used owing to good formability and elasticity.
Some TPEs are used to impart soft tactile properties or seal electric appliances or automotive parts.
Industry Relation / TPE Demand by Types
The world TPEs demand by types in year 2004, 2009 and 2014
Industry Relation / TPE Demand by Region
The world TPEs demand by region in year 2004, 2009 and 2014
Industry Relation / Companies
in the World...
DSM
Dynasol
Dow Chemical
DuPont
Hexpol
Kraton Polymers
in Turkey...
Enplast
Elastron
Sustainability / Health and Environmental
Thermoplastic elastomers are stable materials.
They decompose slowly under normal circumstances.
When decomposed they usually convert into the products which are not hazardous
and do not pose any problems.
The products containing polyolefins and PVC should be handled with care so as to avoid
their overheating.
They should be disposed off properly to avoid their burning because they emit
isocyanates and caprolactam, which are potential pollutants and cancer producing
carcinogenic agents.
Industry Relation / Application Areas
Thermoplastic elastomers have replaced rubber in many applications,

the automotive industry and also in seals,
general purpose,
overmolding,
sporting Goods,
consumer applications,
gaskets,
medical/healthcare applications,
weather-stripping and more.
Finally...

Advantages

Disadvantages
They can be processed speedily, efficiently and economically.
TPEs can be easily colored by most types of dyes.
lightweight,
elastic recovery properties with in a specific temperature range,
metal replacement,
noise reduction by self lubrication,
very good electrical insulation properties,
heat resistance with in a specific temperature range,
oil resistance, improved adhesion, tear resistant surface,
low permeability and colorable
can be made in a variety of hardness grades.
In comparison to thermoset rubbers TPE materials have decreased chemical & environmental resistance.
The cost of TPE materials are higher than the
thermoset materials
they can not be used with fillers in order to make products requiring large amounts of material at low cost
thermal resistances as they melt or become soft at high temperatures and lose their rubbery
behavior.

Thanks for your attention....
Full transcript