We need to produce selectively reflecting cholesteric liquid crystalline rubbers, and they should be sufficiently stable that they are free-standing. Even if we polymerize and crosslink between substrates, in the end we need to remove the substrates and we want to end up with a film that is stable. If it swells in contact with a solvent, that is fine, but it shouldn't disintegrate (which our current products do...). We have bought the only reactive chiral mesogen that Synthon sells, Cholesteryl (4-(6-acryloyloxy-hexyloxy)benzoate (I asked them about this, and the reason that they cannot offer others is that many reactive mesogens are patent-protected, making it too expensive for them to offer them), but this melts only at 73°C. So we have tried mixing it with other reactive mesogens from Synthon to bring down the melting point, but then we get phase separation during polymerization, because the other mesogens are not cholesteryl esters. We then tried adding our reactive cholesteryl ester, together with crosslinker and photoinitiator, to a mixture of non-reactive mesogens, that together produces a selectively reflecting cholesteric phase at room temperature. But in the end we then have something like 75% of non-reactive molecules, and the result is that after polymerization we have no stable film. Rinsing in chloroform everything seems dissolved, so if there was any elastomer forming, it must be in extremely small size.

Any suggestions of which commercially available compounds we can use (we are not a synthetic chemistry group...) and/or suggestions on how to formulate a useful mixture for producing a colorful rubber would be greatly appreciated! Thanks a lot. I assume that our target mixture should have as close to 100% reactive molecules as possible.

PS: I attach the structures of the reactive mesogens that we currently have available (all from Synthon).

PS 2: we need fairly large quantities of the final mixture, typically in the several hundred mg to gram range, so this is another reason why we are looking for commercially available materials.