Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: bashir2008 on 17/07/2009 08:17:47

Title: How to do a density experiment
Post by: bashir2008 on 17/07/2009 08:17:47

Hello everyone:

I have a question regarding how to get the bulk and the solid density of some polymers
 
I do have polypropylene and polyethylene pellets (beads) and i need to find out the bulk and solid density of these pellets... i know that the easier experiment to do it is to take a certain amount of the pellets and put in a beaker and fill it with a liquid and find out the voulme and the mass of the pellets..,,,etc
 
My question is what is the best liquid to use here as i am looking for something that has a density less  than the pellets..so the pellets wont float
 
Could you please tell me which is the common liquid that i can use ?
 
I tried to use Ethanol but i donot know if the ethanol wont effect the pellets..
Please try to help me
 
Kind regards

Title: How to do a density experiment
Post by: Bored chemist on 17/07/2009 14:55:11

Ethanol shouldn't affect polyethylene or polypropylene. It's flammable of course so be careful.

Title: How to do a density experiment
Post by: RD on 18/07/2009 12:22:14

What about putting the beads in a mesh bag* with a lead weight to make them sink in water.
Then repeat the experiment only using the weight and empty bag, (once they have completely dried).
Subtract the displaced volumes and you will have the volume of the beads only, (without the use of exotic liquids), 

[* lets water in, but mesh smaller than beads].
 

Title: How to do a density experiment
Post by: bashir2008 on 24/07/2009 20:54:51

Thanks for replying..but i dont hav a mesh bag,, so i would rather prefer to use a liquid..but which one ?

Title: How to do a density experiment
Post by: lyner on 24/07/2009 22:06:17

Any cloth would do.
Much more easily obtained (and a lot safer) than some exotic chemical.