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Specialty Chemistry Forums => Citizen Chemist => Topic started by: xchcui on March 31, 2019, 03:33:52 AM

Title: Why is light naphtha better solvent than heavy naphtha?
Post by: xchcui on March 31, 2019, 03:33:52 AM
Hi.
I read that light naphtha is used, among other, as a solvent. According to my understanding, light naphtha has higher volatility than heavy naphtha. Is this (the volatility) the reason that makes it dissolve the rubber better than heavy naphtha?

Heavy naphtha, which has a lower volatility than light naphtha, seems to stay longer on rubber before it evaporates and it makes more sense that, for that reason, they should dissolve the rubber better than light naphtha, which evaporates more quickly.

I have mineral turpentine which contains "Naphtha (petroleum), hydrodesulfurized heavy" (CAS number: 64742-82-1). As far as I understand, it is heavy naphtha. Can I use it to dissolve rubber in the same efficiency as light naphtha? Or it is less/more efficient than light naphtha?
Thanks.
Title: Re: Why is light naphtha better solvent than heavy naphtha?
Post by: Borek on March 31, 2019, 06:37:05 AM
Light naphtha contains smaller molecules, smaller molecules can penetrate much more easily.

Evaporation doesn't change this property. Yes, light naphtha is much more volatile and evaporates faster, but it just means it is inconvenient to use in the open.
Title: Re: Why is light naphtha better solvent than heavy naphtha?
Post by: xchcui on March 31, 2019, 10:50:40 AM
Light naphtha contains smaller molecules, smaller molecules can penetrate much more easily.

Evaporation doesn't change this property. Yes, light naphtha is much more volatile and evaporates faster, but it just means it is inconvenient to use in the open.
So,it is related to the size of the molecules chain
and i assume that if i immerse a piece of rubber in heavy naphtha solution vs light naphtha solution,the rubber will dissolved faster and better in the light one.
But if i only apply(not immerse)a layer of heavy naphtha on a piece of rubber vs a layer of light naphtha,wouldn't the heavy naphtha have more time to work on the rubber and dissolve it better vs the light naphtha that will evaporate faster and will not have time to dissolve it,even though the light naphtha has better penetration?
Title: Re: Why is light naphtha better solvent than heavy naphtha?
Post by: xchcui on April 02, 2019, 04:36:15 AM
Borek?Anyone?
Title: Re: Why is light naphtha better solvent than heavy naphtha?
Post by: Mitch on April 02, 2019, 01:38:34 PM
Light naphtha contains smaller molecules, smaller molecules can penetrate much more easily.

Evaporation doesn't change this property. Yes, light naphtha is much more volatile and evaporates faster, but it just means it is inconvenient to use in the open.
So,it is related to the size of the molecules chain
and i assume that if i immerse a piece of rubber in heavy naphtha solution vs light naphtha solution,the rubber will dissolved faster and better in the light one.
But if i only apply(not immerse)a layer of heavy naphtha on a piece of rubber vs a layer of light naphtha,wouldn't the heavy naphtha have more time to work on the rubber and dissolve it better vs the light naphtha that will evaporate faster and will not have time to dissolve it,even though the light naphtha has better penetration?

Your logic seems right.
Title: Re: Why is light naphtha better solvent than heavy naphtha?
Post by: xchcui on April 03, 2019, 12:07:12 PM
Hi Mitch.

I hope so :)