new therban compound development - sgf · 2018. 9. 17. · therban lt2007 change in elongation [%]...

New Therban ® Compound Development

Lars PetrenDr. Susanna Lieber, Dr. Sarah David, Dr. Ulrich FrenzelSGF 24th of November,

ARLANXEO � RubberCon � 2016-06-082

Root Causes for Vehicle BreakdownCooling System Failure Most Common

� Cooling system failure is one of the most common causes of

vehicle breakdowns

� Over 60% of water pump

failures can be attributed to seal failure

� Just 0.6 mm of deposits can reduce the heat dissipation by

40%

Failure Analysis0 2 4 6 8 10 12 14 16 18 20 22

safety system

differential

gas installation

steering

power train

brakes

transmission

fuel circuit

engine

electrical circuits

cooling system

Source: CG Car-Guarantee, Ardeco


Requirements and Coolant Technologies

Requirements Technologies

� 5 Functions of engine coolants:

‒ Effective heat transfer fluid

‒ Protection of all materials – no deposit

‒ Environmentally friendly

‒ Freeze protection

‒ Boiling protection

� Water plus Ethylene or Propylene glycol

� Corrosion inhibitor to protect materials

‒ Standard coolant contains borates and silicates

‒ The organic acid technology coolant contains neutralized organic acids – silicate free and extended lifetime

� New coolants are additivated by Glycerin –

different ageing behavior than pure Ethylene or

Propylene glycol based coolants


Cavitation

https://en.wikipedia.org/wiki/Cavitation � https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=277481&docFormat=PDF


Volvo Trucks

� http://www.volvotrucks.com/SiteCollectionDocuments/VTNA_Tree/ILF/Products/Powertrain/power_brochure_050510.pdf

� P11

� P13


CAT

� http://www.cat.com/en_US/by-industry/marine/marine-product-support/engine-advice/cylinder-liners.html


Cavitation of a liner

Mahle

� https://www.youtube.com/watch?v=5_7PtvziB-Q


G13 as Commercial Coolant ExampleComposition

Chemical StructureExample G13

� Composition based on Ethylene glycol, Glycerin and Sodium ethyl hexanoate according to data sheet

� Also reaction products of Ethylene glycol and Sodium ethyl hexanoate e.g. Diethyleneglycolmonoethylhexanoate identified through analysis

approx. 25 – 50% approx. 2.5 – 10%

approx. 2.5 – 10%

Stringent Requirements VW

� Ageing in G13, 1000h at 150°C

− EAB change: < 25%

� Ageing in hot air, 1000h at 150°C

− EAB change: < 40%


G13 as Commercial Coolant ExampleChange of Coolant Composition during Ageing

Development of Acid during AgeingAgeing of G13

� Ageing at 150°C changes the composition of the fluid

� Samples were taken at several times and the

composition determined by GC MS

� Significant increase of Methyl-2-ethylhexanoat,

Diethyleneglycol monoethylhexanoat, 2-Methyl-

dioxolane and free Ethyl hexanoic acid can be seen

� Addition of Fe ions seems to speed up the change

of the compositionAgeing Time [h]

Pea

k A

rea

/ Ini

tial W

eigh

t

Ethyl hexanoic acid


Evaluation of Therban based Compounds

� Simple formulation for seals using N550 as filler

� Standard 34% ACN as well as

low temperature grades with

17% and 20% ACN

Formulation 1: N550


Formulation 1: Ageing in Water/Ethylene Glycol Mixt ures High Swell in Presence of Ethyl Hexanoic Acid

Volume Swell w/o Acid Volume Swell with Acid

� Low volume swell in a coolant mixture without OAT technology

� Extremely high volume swell when Ethyl hexanoic acid is present

Ageing in water / Ethylene glycol 50 / 50 at 120°C Ageing in water / Ethylene glycol / Ethyl hexanoic acid 47.5 / 47.5 / 5

0

1

2

3

4

5

6

7

8

9

10

Therban 3407 Therban LT1707VPTherban LT2007

Vol

ume

Sw

ell [

%]

14d

21d

42d

0102030405060708090

100

Therban 3407 TherbanLT1707VP

Therban LT2007

Vol

ume

Sw

ell [

%]

14d

21d

42d


Analysis after Ageing with Ethyl Hexanoic AcidEthyl Hexanoic Acid and Esters in Compound after Age ing

GC MS Spectrum Chemical Composition

� Extraction of samples after ageing and analysis ofextract with GC MS

2-Ethylhexanol

Ethylhexanoic acid

Ethylhexanoic diethylenglycolester

Ethylhexanoic ethylhexylester

Diethylenglycoldiethylhexanoat

� Esters of ethyl hexanoic acid with ethyleneglycol formed during ageing

� Swelling caused by ethyl hexanoic acid andesters

Ageing in water / Ethylene glycol / Ethyl hexanoic acid 47.5 / 47.5 / 5


Formulation 1: Ageing in Water/Ethylene Glycol Mixt ures High Change in Elongation in Presence of Ethyl Hexa noic Acid

Change in Elongation w/o Acid Change in Elongation with Acid

� Increase in elongation after ageing and nearly no change in hardness

� Extremely loss in elongation

Ageing in water / Ethylene glycol 50 / 50 at 120°C Ageing in water / Ethylene glycol / Ethyl hexanoic acid 47.5 / 47.5 / 5

0

2

4

6

8

10

12

14

16

18

20

Therban 3407 Therban LT1707VP Therban LT2007

Cha

nge

in E

long

atio

n [%

] 14d

21d

42d

-70

-60

-50

-40

-30

-20

-10

0Therban 3407 Therban

LT1707VPTherban LT2007

Cha

nge

in E

long

atio

n [%

]

14d

21d

42d


Formulation 1: Ageing in Water/Ethylene Glycol Mixt ures High Change in Modulus in Presence of Ethyl Hexanoi c Acid

Change in M100

� High increase in modulus for compounds aged in contact with Ethyl hexanoic acid

� At the same time hardness is decreasing

� Clear indication of embrittlement during ageing

Comparison of modulus at 100% elongation for different ageing conditions

0

10

20

30

40

50

60

70

80

90

Therban 3407 Therban LT1707VP Therban LT2007

Cha

nge

in M

100

[%]

ethyl hexanoic acid 21dethyl hexanoic acid 42dwater / glycol 21dwater / glycol 42d

-20

-15

-10

-5

0Therban 3407 Therban

LT1707VPTherban LT2007

Cha

nge

in H

ardn

ess

[%]

14d21d42d

Hardness after ageing in water / Ethylene glycol / Ethyl hexanoic acid






17% and 20% ACN

Formulation 1: N550

� Therban® LT with a blend of N990 and N774 to reduce fluid

ageing

Formulation 2:Combination of N990 and N774


Formulation 1 Formulation 2

� Volume swell is significantly reduced

� Hardness is decreased

� Change in elongation is increased

� However – modulus is still increased

� Change of elongation at 150°C, 504h is -47%!

� Improvement in hot air resistance needed

Improvements

Formulation 2: Ageing in Water/Ethylene Glycol Mixt ures Volume Swell Reduced by Use of N990

Ageing in water / Ethylene glycol / Ethyl hexanoic acid 47.5 / 47.5 / 5, for 504 h at 120°C

-80

-60

-40

-20

0

20

40

60

80

100

Cha

nge

in %

hardness change

change in elongation

change in M100

volume swell

-80

-60

-40

-20

0

20

40

60

80

100

Cha

nge

in %

hardness change

change in elongation

change in M100

volume swell


Improvement of Hot Air Aging in Formulation 2 Carbonates Effective, but High Swell

Improvement with Carbonates Change during Ageing

� Addition of Li2CO3, which is known to improve hot air ageing

� Use of calcinated clay which has been investigatedfor excellent long term compression set

� Improve hot air ageing when using Li2CO3

� BUT high volume swell when using Li2CO3

Ageing in hot air and G13 at 150°C for 504h

-40

-30

-20

-10

0

10

20

30

change in elong. volume swell G13 change inelongation G13

chan

ge in

%

N990

calc. clay

calc. clay + Li2CO3


New Filler Type Necessary

New Mineral Filler Test Formulation with new filler

� Low surface area needed for good compression set

� BET surface < 20 m2/g

� high pH needed to prevent ageing of elastomers in organic acids

� pH > 7

� Basic, naturally occuring mineral filler identified

� Comparison of N990 and New Filler


Test Formulation with New FillerImprovement of Properties after Ageing

Ageing in Hot Air and G13 Results

� Volume swell is similar between New Filler and N990

� Change in elongation after ageing in both hot air

and G13 is greatly improved for the formulation

with the new filler

� Further evaluation with this filler

Aging in different media for 21 d at 150°C

-40

-30

-20

-10

0

10

20

30

change in elong. volume swell G13 change in elongationG13

Cha

nge

in %

N990

new filler






17% and 20% ACN

Formulation 1: N550

� Therban® LT with a blend of N990 and N774 to reduce fluid

ageing

Formulation 2:N990 combined with N774

Formulation 3:New Filler combined with N774

� Use of New Filler as main filler

to improve ageing

� Standard 34% ACN and 17%

ACN LT grade tested


Formulation 3: Ageing with added Ethyl Hexanoic Aci dImproved Aging of Compound with New Filler

Formulation 1 +2 Formulation 3

� Use of carbon black only - Improvement in swellwhen using low surface black

� Significant improvement when using New Filler in swell and elongation

-80

-60

-40

-20

0

20

40

60

80

100

Therban 3407 Therban LT1707VPCha

nge

in %

elong.

volume-80

-60

-40

-20

0

20

40

60

80

100

Therban3407/N550

TherbanLT1707VP/N550

Therban LT1707VP N990

Cha

nge

in %

elong.

volume

Ageing in mix with Ethyl hexanoic acid for 504h at 120°C Ageing in mix with Ethyl hexanoic acid for 504h at 120°C


Newly developed Therban Compound Meets VW Specifica tion

Ageing in G13

Volume Swell in G13

Ageing in Hot Air

Compression Set ��

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RequirementsTherban

New Filler Compound

Hardness ShA 70 69Elongation at Break % min 200 300Tensile Strength MPa min 12 20M100 MPa min 3 7DVR PVW 3307 150°C 22h (50 % defl.) % max 60 60Tear resistance ISO34-1A N/mm min 4 5Heat Ageing 1008h, 150°CHardness ShA 76delta Hardness ShA max 8 7Tear resistance ISO34-1A N/mm 5Elongation at Break % min 120 254Tensile Strength MPa 17M100 MPa min 3 11E@B Change % max 25 -15TS Change % max 25 -14M100 Change % 54Coolant Ageing, 1008h, 150°CHardness ShA 76delta Hardness ShA max 8 7Elongation at Break % min 120 206Tensile Strength MPa 18M100 MPa 14Volume Swell % max 3 3E@B Change % max 40 -31TS Change % max 25 -9M100 Change % 97


Conclusion

Therban ® compound meeting high requirementsin contact with coolant could be generated

A filler with low surface area and high pH suitablefor contact with coolant could be identified

Based on findings of media ageing, compoundcomposition has been modified

Change of test fluid during ageing has beenmonitored to understand compound behaviour ��

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