25
Influence of polymer properties on final features of technical rubber parts Dr. Martin Mezger Technical Marketing Manager Zahnriementagung 2013 Dresden
Influence of polymer properties on final features of technical rubber parts
Dr. Martin Mezger
Technical Marketing ManagerZahnriementagung 2013 Dresden
Agenda
Motivation Requirements for polymers and compounds Tailor-made fillers for enhanced properties
- Processing- Final properties Therban AT for superior processing and properties
- Processing- Final properties Conclusion
2
Motivation
Timing belts in engines
3
TDI Engine
Good aging behavior
Double bonds in main chainGood oil
resistancePolarity
Good processing behavior
Low compound viscosity
High vulcanizatemodulus
Strong filler-filler and polymer interaction
Polymer Compound/Vulcanizate
Lifecycle up to 250,000 kmat temperatures up to 130°C
Spec. of a “modern” timing belt
Motivation
Polymers for timing belt applications
NBR Poly(acrylonitrile-butadiene)
CH CH2
N
C
CH2 CH CH CH2 CH CH2
CH
CH2
a b c
- Aging behavior+ Oil resistance
XNBR
CH CH2
C
O
OHd
HXNBR
CH CH2
C
O
OHd
Functional-ization
Carboxylation
CH3
HNBR Hydrogenated Poly(acrylonitrile-butadiene)
CH CH2
N
C
CH2 CH2 CH2 CH2 CH CH2
CH2a b c
+ Oil resistance Aging behavior+
Hydrogenation Hydrogenation
44
Motivation
Compounds for timing belt applications
5
Polymers
HNBRTherban
FillersCarbon Black
SilicaSilica with Silane
Zn-Diacrylate
Cross-linkers
PeroxidesC-C BondsSulphur
C-SX-C Bonds
34 wt% ACN yields good compromise
between low temperature
behavior and oil resistance
At high temperaturesC-C bonds
more stable thanC-SX-C bonds
?
Filler-filler and filler-polymer interactions determine mechanical and dynamic-mechanical properties and their dependence on temperature
5
Processing behavior (i.e. extrusion)
6
During extrusion unvulcanizedcompounds undergo high
deformations at high temperatures
Good processing behavior, if compound viscosity is low at
relevant shear rates
6
Improvement of
processing behavior
Shear rate
Extrusion process
T = 60°C
Visc
osity
HNBR + 60phr N330 (carbon black)
HNBR unfilled
60%
25%
Conclusion – Processing
77
Improvement of processing behaviorwithout losing final propertiesTarget
Compound viscosity determined by polymer viscosityand reinforcement
Variation of reinforcement
By variation of Type Amount of
filler
Variation of compound viscosity
Filler Polymer
? Influence on the final properties
of the vulcanizate
Filler-filler and filler-polymer interaction
Physical filler-polymer interaction (Van der Waals)
Chemical filler-polymer interaction (Covalent Bond)
Can act as plasticizer
Carbon Black Silica + Silane ZDA + Therban XT
Energy dissipation Temperature Adhesion
Mechanical properties Service life Processing Abrasion
Processing Service life Abrasion
Energy dissipation Temperature Mechanical
properties
8
– –
+ +
XHNBR + ZDA – Processing behavior
Extrusion process
During extrusion unvulcanizedcompounds undergo significant
deformations at high temperatures
Good processing behavior, if compound viscosity is low at
relevant shear rates
HNBR + 60phr N330 (carbon black)
HNBR unfilled
XHNBR + 60 phr ZDA
T = 60°C
Improvement of
processing behavior
Visc
osity
Shear rate
Viscosity of XHNBR + ZDA lower than viscosity ofHNBR standard grade: superior processing behaviorConclusion
9
Filler-filler and filler-polymer interaction
Physical filler-polymer interaction (Van Der Waals)
Chemical filler-polymer interaction (Covalent Bond)
Can act as plasticizer
Energy dissipation Temperature Adhesion
Carbon Black Silica + Silane ZDA + Therban XT
Mechanical properties Service life Processing Abrasion
Processing Service life Abrasion
Energy dissipation Temperature Mechanical
properties
Thermoplastic filler with ionic
interaction
Peroxidiccross-linking
causespolymerization of
Zn-diacrylate
Ionic filler-polymer interaction
Energy dissipation Processing Temperature Mechanical properties Service life Abrasion
10
– –
+ +
+
Standard HNBR +
Carbon Black
Standard HNBR +
Silica + Silane
Final properties
Final properties of a timing belt
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
betterworse
11
ca. 100,000km
–+
– – –– ––
+
+
+
++
+
Standard HNBR +
Carbon Black
Standard HNBR +
Silica + Silane
Final properties
Final properties of a timing belt
12
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
betterworse–
+
– – –– ––
+
+
+
++
+
ca. 100,000km
Standard HNBR +
Carbon Black
Standard HNBR +
Silica + Silane
XHNBR + ZDA
Final properties
Final properties of a timing belt
13
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
ca. 250,000km
betterworse–
+
– – –– ––
+
+
+
++
+
ca. 100,000km
Standard HNBR +
Carbon Black
Standard HNBR +
Silica + Silane
XHNBR + ZDA
Final properties
Final properties of a timing belt
14
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
ca. 250,000km
betterworse–
+
– – –– ––
+
+
+
++
+
ca. 100,000km
Conclusion – Processing
1515
Compound viscosity determined by polymer viscosityand reinforcement
Improvement of processing behaviorwithout losing final propertiesTarget
Variation of reinforcement
By use of
ZDA Therban XT
Variation of compound viscosity
Filler Polymer
Influence on the final properties
of the vulcanizate
By variation of
Variation of polymer viscosity
Molar mass?
Conclusion – ProcessingReduction of molar mass via olefin metathesis
Nobel Prize Chemistry 2005 by Robert H. Grubbs, Richard R. Schrock, Yves Chauvin
16
De Gennes1
16 1) Nobel Prize Physics 1991
Visc
osity
Shear rate
Extrusion
Therban© 3406ML(1+4)100ºC 63
Therban© 3404ML(1+4)100º C´39
Therban© 3400ML(1+4)100ºC < 2
x8 x7 x30
x200
Therban© 3406+ 60phr N330
x1.25
x1.6
Final properties
Final properties of a timing belt
17
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
ca. 250,000km
Standard HNBR +
Carbon Black
Standard HNBR +
Silica + Silane
XHNBR + ZDA
XHNBR + Therban
AT + ZDA
betterworse–
+
– – –– ––
+
+
+
++
+
Standard HNBR+ Carbon Black
Standard HNBR + Silica + SilaneXHNBR + ZDA
XHNBR + Therban AT + ZDA
Final properties
Final properties of a timing belt
18
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
ca. 250,000km
Decrease of molar mass – increased
number of dangling chain ends
Reduction of mechanically
effective cross-links
Problem
P. Flory1
1) Nobel Prize Chemistry 1974
betterworse–
+
– – –– ––
+
+
+
++
+
Decrease of molar mass – increase of dangling chain ends
Reduction of mechanically effective
cross-links
Compensation of reduced molar mass by increased amount
of peroxide
Final properties
Final properties of a timing belt
19
Therban© 3406ML(1+4)100ºC 63
Therban© 3404ML(1+4)100ºC 39
Therban© 3400ML(1+4)100ºC < 2
Cro
ss-li
nk d
ensi
ty1
Amount of peroxide2
constant cross-linking
density
1) Number of cross-links per 1000 C-atoms of the main chain2) Number of Bis(tert-butylperoxyisopropyl)benzene per 1000 C-atoms of the main chain
+3.5phr
+1.6phr
Final properties
Final properties of a timing belt
20
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
ca. 250,000km
Standard HNBR+ Carbon Black
Standard HNBR + Silica + SilaneXHNBR + ZDA
XHNBR + Therban AT + ZDA
XHNBR + Therban AT + ZDA
adapted cross-link density
betterworse–
+
– – –– ––
+
+
+
++
+
Standard HNBR+ Carbon Black
Standard HNBR + Silica + SilaneXHNBR + ZDA
XHNBR + Therban AT + ZDA
XHNBR + Therban AT + ZDA
adapted cross-link density
Final properties
Final properties of a timing belt
21
Adhesion
Service lifeAbrasion
Energydissipation
Mechanicalproperties
Processing
ca. 250,000km
Superior processing
behavior and improved final
productsbetterworse–
+
– – –– ––
+
+
+
++
+
Conclusion
Why do we need special products like liquid HNBR or XHNBR?
2222
Standard (HNBR + Carbon Black)
Specific optimization is based on the fundamental understanding of the polymer, its network and its interaction with fillers
Longer lifetime Lower energy dissipation
Optimized formulation Superior processingOptimized formulation
Standard (HNBR + Carbon Black)
Energy consumptionduring production
Energy consumptionduring lifetime
Green2 Belt
LANXESS BU HPE – experts in advanced physical characterization of polymer materials
23
Our technical expertise offers the efficient development and optimization of elastomer products
We do not only have an in-depth knowledge of polymers, but also know about the influence of fillers, which enable us to offer solutions for Superior processing Longer lifetime Low energy dissipation
Safe harbour statement
This presentation contains certain forward-looking statements, including assumptions, opinions and views of the company or cited from third party sources. Various known and unknown risks, uncertainties and other factors could cause the actual results, financial position, development or performance of the company to differ materially from the estimations expressed or implied herein. The company does not guarantee that the assumptions underlying such forward looking statements are free from errors nor do they accept any responsibility for the future accuracy of the opinions expressed in this presentation or the actual occurrence of the forecasted developments.No representation or warranty (express or implied) is made as to, and no reliance should be placed on, any information, including projections, estimates, targets and opinions, contained herein, and no liability whatsoever is accepted as to any errors, omissions or misstatements contained herein, and, accordingly, none of the company or any of its parent or subsidiary undertakings or any of such person’s officers, directors or employees accepts any liability whatsoever arising directly or indirectly from the use of this document.
