Field Test to Identify Silicone

If you have known samples of both materials, you could use the flame/hot knife/sniff test. First test your known materials then compare the odors to the unknowns.

This will give you a guide: IDENTIFICATION OF A POLYMER

Don't inhale too much smoke when performing the test.

Good luck!

Thanks - I will give it a try

The other thing that comes to mind is a razor blade penetration test.

If you push a single edged razor blade into silicone, it will penetrate the silicone much more readily than the polysulfide.

Use some form of weight and see how much force it takes to penetrate the silicone.

Then go to polysulfide and you should see much less penetration of PS with that weight. Add weight till you get penetration and compare.

These are all very subjective. You could have it analyzed.

Burn the stuff to ashes: silicone will give some fine white dust of silica.

Polysulphide will have some smell as sulphur at burning.

Burn with oxidative conditions and only a small sample otherwise toxic.

RHABE

Thanks,

this test Worked well - Along with other tests provided by respondants I have determined the sealant I'm working with is Polysulfied.

Great Forum - Very informed and intellegent readers/participants.!!!

This is final test and have done to differenciate between silicon and other adhesive when needed.

If it is actual part in field used pin to poke the seal and then known silicon and other and is very subjective but give info one need to go further to confirm or not

Would a durometer test provide the same information ?

Yes

Firstly, is there a specific reason for needing silicone? If polysulfide works, why not use it? Silicone stands 250ºC continuously Controlled temperature soldering irons are available. Set to 250ºC and keep incontact with the sealant. If it passes it should be OK. Of course Viton will also pass this. However, if a vendor is willing to give you something that costs twice as much as silicone for the price of silicone, that is the vendor's problem.

Bioramani

Thank you for the information. In my application the issue is

cohesion to another sealant - a butylene. esentialy - The butylene will not adhere to the silicon to the point I could simulate and observe cohesive failure. That is, the two materials will peel apart leaving two slick surfaces.

If minimising cohesion to another surface is the issue, can you consider the option of smearing a hiigh viscosity (20000 centipoise) silicone oil between the two contacting surfaces? This is the silicone used for lubricating disposable sterile syringes. Even after five years of being on the shelf the plunger will move effortlessly in operation.

This will free you from selecting an inherently non stick sealant.

Sorry for the misunderstanding - Actually I'm trying to improve cohesion. That is, the butylenes will not stick well to the silicone base sealant. So - I must not use silicone base adhesive or come up with a way to improve the cohesive bond between silicone and a polymer such as polysulfide. My first problem was determining what I had. Input from other correspondents provided me the information to test for silicone. I had Polysulfide. I have since made several sample coupons of various known sealants for future identification testing's.

In earlier life working for the big companies there was always a lab handy on campus to get your analysis in fast turn around. I miss the big $ environment and the technology but really enjoy the lack of nemesis I have here.

Now that I have found you helpful folks out there I think I will just stay where I'm at. - 3 more years to Retire.....then my time will be working on something between becoming a Rock star and/or a doting grandparent. ?? I'm already a doting grandparent ( which means a major drain on the finances) and have little to no musical talent.