Refractive Index matching to PMMA

[ccatceimy]

Hi

I am trying to figure out the right liquid to use that has the following properties:

optically clear/colorless

refractive index of 1.490

viscosity of 5cSt or lower at 25oC

compatible with PMMA and either polyurethane elastomers or silicone elastomers.

 

I have looked at mineral/white oils but can not get to a sufficiently low viscosity and the index value.

 

Thanks