Formulating the right Polyurethane adhesives or sealants that can resist to extreme environmental conditions such as high and low temperatures, humidity and chemical aggressions while ensuring durable high performance is a challenge.
Polycarbonate Diols (PCD) and Polycarbonate-based Polyurethane Prepolymers
offer customizable possibilities with superior and long-term retention of designed performances, without modification of initial properties after being exposed in harsh environments.
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The
outstanding durability of Polyurethane adhesives & sealants based on PCD or Polycarbonate-based Polyurethane Prepolymers
is obtained thanks to different performances, such as:
Access more information about the best-in-class performances of Polycarbonate Diol-based Polyurethane adhesives, click on the pictures below:
Increased adhesion properties of Polyurethane adhesives
Polycarbonate Diols and Polycarbonate-based Polyurethane Prepolymers allow adhesive formulators to
improve the adhesion properties of their
Polyurethane adhesives.
A
cross-cutter adhesion test was run in order to compare the adhesion properties of Diol-based Polyurethane once a part of the coating was removed
(see picture 1).
Picture1: Cross-cut adhesion test
ISO 2409
Test method: part of the coating is removed
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| Base polyol |
T-peel
(KN/m, ISO11339:2010) |
| Eternacoll® grades |
0 |
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0: No modification of adhesion properties
1: <5%
2: from 5% to 10% |
Polyadipate of
1,6-hexane diol |
2 |
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Table 1: Modification of adhesion properties of polyol-based Polyurethane after a cross-cut adhesion test
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The results in
Table 1 show that compared to Polyurethanes formulated with standard diols, those formulated with
Eternacoll® or
Eternathane®
Polycarbonate-based Polyurethane Prepolymers show
excellent adhesion properties after the cross-cut adhesion test.
Moreover,
Figures 2 and 3 illustrate that Eternacoll® or Eternathane
® provide a better T-peel and Lap-shear strength than standard diols for adhesives. This results in an
improved durability of Polyurethane adhesives.
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Figure 2: T-peel test of PCD-based Polyurethane adhesives
(kN/m, ISO 11339:2010) |
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Figure 3: Lap-shear strength of PCD-based Polyurethane adhesives
(kPa, ISO 4587:2003) |
Excellent water resistance of Polyurethane adhesives
Polycarbonate Diols (PCD) and Polycarbonate-based Polyurethane Prepolymer allow formulators to provide
extremely durable Polyurethane adhesives & sealants thanks to
increased resistance to water / hydrolysis.
Figure 4 illustrates that
Polyurethane based on Eternacoll® or Eternathane®
better retains the initial Polyurethane properties in extreme humid conditions. Compared to standard Polyether Diols, it shows a very
low variation of the T-peel initial value after exposure to water.
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Figure 4: Water resistance of PCD-based Polyurethane adhesives
Water immersion at 80° C for 15 days
ISO 9142:2003 - Adhesives - Guide to the selection of standard
laboratory ageing conditions for testing bonded joints |
Therefore,
Polyurethane adhesives & sealants formulated with
Eternacoll® or Eternathane® withstand
extreme humid conditions and remain intact after long-term exposure to water and humidity.
Increased chemical resistance of Polyurethane adhesives
Exposure to harsh solvents and fluids tends to damage
Polyurethane adhesives & sealants over time.
Polycarbonate Diols (PCD) and Polycarbonate-based Polyurethane Prepolymers can help you to overcome this annoying constraint by
enhancing the chemical resistance of your Polyurethane formulations.
An ethanol resistance test was run in order to compare the chemical resistance of Diol-based Polyurethanes
(see picture 2).
As illustrated on
Figure 5, Polyurethane formulated with Eternacoll® or Eternathane® shows an improved resistance to harsh solvents compared to Polyurethane based on benchmark Diols.
Picture 2: Ethanol resistance test of
PCD-based PU
ISO 2812-1:2007
Determination of resistance to liquids
Part 1: Immersion in liquids other than water
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Figure 5: Ethanol resistance of Diol-based PU
*5 = Intact adhesive after exposure
4 = Slight change in color
3 = Light mark
2 = Strong mark
1 = Adhesive removal
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The use of Eternacoll® or Eternathane® in your Polyurethane formulations allows you to
provide highly durable Polyurethane adhesives that can
better resist to exposure of chemicals.
This makes Eternacoll® or Eternathane® suitable for applications in which
Polyurethane adhesives have to
resist to very harsh environmental conditions.
High thermal stability of Polyurethane adhesives
Is
temperature resistance a must-have for your
Polyurethane adhesives? If you can’t afford to provide Polyurethane that tends to yellowish over time, then Polycarbonate Diols (PCD) and Polycarbonate-based Polyurethane Prepolymers is the technology you have always been looking for!
Polycarbonate Diols provide a
very high thermal stability to Polyurethane adhesives compared to traditional Polyester and Polyether Diols, thanks to excellent heat resistance.
Figure 6 illustrates that Polyurethane based on
Eternacoll® polycarbonate diols or Eternathane® polycarbonate-based polyurethane prepolymers has a very
low variation of the T-peel initial value after artificial weathering, compared to standard Polyether and Polyester Diols.
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Figure 6: Variation of the initial value of T-peel for Diols-based PU
Test conditions: Dry heat, wet heat and cold
ISO 9142:2003 - Adhesives - Guide to the selection of
standard laboratory ageing conditions for testing bonded joints
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Eternacoll® or Eternathane® based Polyurethane shows an
excellent retention of initial properties, even after exposition to extreme weather conditions, for an improved durability of your adhesives & sealants!
Therefore, Eternacoll® or Eternathane®
allow to provide
highly durable Polyurethane adhesives & sealants that resist to heat and can be used for
applications exposed to high temperatures.
Improved mechanical properties of Polyurethane Adhesives
Formulating Polyurethane with
Polycarbonate Diols or polycarbonate-based polyurethane prepolymers maximize the performance of your adhesives & sealants formulation. How?
Polyurethane based on
Eternacoll® or Eternathane® shows
better mechanical properties compared to Polyurethane based on traditional Diols:
- The Polyurethane adhesive has a better tensile strength (+329%) and is therefore less elastic (Figure 7)
- It also shows a better hardness (+173%), as illustrated on Figure 8
Figure 7: Tensile strength of Diol-based PU |
Figure 8: Hardness of Diol-based PU |
The improvement of mechanical properties allows you to provide less elastic Polyurethane and with a better hardness, for a
highly durable adhesive!
Improvement of adhesion performance thanks to diol blends
Last but not least, you can
cost effectively improve the adhesion properties of your Polyurethane adhesives
using blends of Eternacoll® or Eternathane® / standard diols.
Eternacoll® or Eternathane® are fully miscible with most of standard diols.
As illustrated on
Figures 9 and 10, you can easily
adjust your formulation according to the cost / adhesion performance you want to get with standard diols content about 10-50% wt.
The adhesion improvement can be strongly enhanced compared to standard diol.
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Figure 9: T-peel of PU adhesives using polycarbonate diols blends
Test method: ISO 11339 :2010
25% wt = 25% of Eternacoll® PCD, 75% of benchmark diol (PTMG)
50% wt= 50% of Eternacoll® PCD, 50% of benchmark diol (PTMG)
100% wt= Benchmark PTMG without Eternacoll® PCD
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Figure 10: Lap-shear strength of PU adhesives using polycarbonate diols blends
Test method: ISO 4587:2003
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