[NorPar]

We are developing an application where we are applying to the surface of an SBR Sheet a Polyurethane Sheet.

We are structural engineers, and we are at a loss to solve the problem that is stopping our progress developing the idea.

We have got this far.

The problem is we are getting staining/discolouration of the Polyurethane sheet when applied to the SBR (Rubber) surface. We understand the problem is caused by the aromatic oils in the SBR blooming out and causing the "yellowing" discolouration of the PU.

The solution would be to place a barrier layer between the SBR and the PU.
For the application we have to retain the flexibility of the PU.

Would any of the members know if there is a film, additive or method that is commercially available to stop the discolouring phenomena.


Many thanks

[typhoon2028]

Could you just add an antioxidant package to the urethane?

[NorPar]

Thanks for the suggestion, the company developing the PU have tried an antioxidant, but the PU still yellows.

We have obtained a sample of a bespoke film from the States that has a barrier film, used for a similar application, and I understand this company had similar problems, they seemed to have solved it using some technique we cannot understand.

Thanks, we are not very productive with the info, we are still looking

[pufeng]

i was thinking possible to use PVDC as the barrer film between them?