Sciencemadness Discussion Board

Extracting Butyl Rubber

Frontier9 - 24-9-2006 at 13:36

I mixed Butyl Rubber Sealant with naphtha and stirred this heterogeneous mixture to form a more or less homogeneous mixture so that the butyl rubber content of the sealant may be dissolved by the maphtha solvent. I then allowed the other contents of the sealant to settle to the bottom of the container and then repeated the mixing process several times to make certain all of the butyl rubber content would dissolve into the solvent. This was done over a 2 day period. I then decanted the liquid portion of the mixture into another container, this liquid is not clear like naphtha by itself but somewhat opaque, presumably due to the dissolved butyl rubber that is suspended in the solvent. Now the problem is that the naphtha solvent is refusing to evaporate. How can I cause the solvent to evaporate so that I can recover the pure butyl rubber? Any suggestions?

nitro-genes - 26-9-2006 at 02:15

Fastest is precipitation by the addition of 50% acetone....

Frontier9 - 26-9-2006 at 19:03

Thanks for the info nitro-genes; I'm assuming by "addition of 50%", I need to add a volume of acetone that is equal to 50% of the volume of the solution that is already in the container. Am I correct in this assumption? Furthermore, I am surprised that acetone which itself is a solvent would cause the polyisobutylene to precipitate out of the solution. What's up with that? Lastly, what about increasing the temperature of the solution by the addition of heat, would this cause the naphtha solvent to evaporate?:cool:

stricnine - 2-10-2006 at 10:05

Try applying vacuum. I have a simple water aspirator that reduces the pressure down to the vapour pressure of water. It will take a lot of water running for a couple of hours (or days!), but it surely will work.

Enjoy!