Can Different Types of Hydrocarbons Mix?

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Discussion Overview

The discussion revolves around the mixing behavior of different types of hydrocarbons, specifically paraffin wax and petroleum jelly, as well as the miscibility of various waxes and oils. Participants explore the physical properties and interactions of these substances when heated and cooled, along with methods for analyzing mixtures of petroleum-based solids and fluids.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • Some participants propose that melted paraffin wax and petroleum jelly would mix at elevated temperatures but may separate upon cooling, with crystallization of wax occurring.
  • Others argue that molten paraffin wax and petroleum jelly would mix completely due to the composition of petroleum jelly, which includes paraffin wax, leading to a harder gel upon cooling.
  • One participant questions the transparency of petroleum jelly, suggesting that wax crystallites may be present within the matrix.
  • Methods for analyzing a mixture of unknown petroleum-based solids and high viscosity fluids are discussed, including optical methods, chromatography, and various spectrometry techniques.
  • A question is raised about the existence of waxes and oils that are mutually immiscible, with a suggestion that beeswax in olive oil may exhibit some separation.
  • Another participant mentions that the rule "like dissolves like" applies, indicating that waxes may not crystallize in mixtures with oils.
  • There is curiosity about whether mixing olive oil and sesame oil with heat would prevent separation during cooling.

Areas of Agreement / Disagreement

Participants express differing views on the mixing behavior of paraffin wax and petroleum jelly, with no consensus reached on whether they would remain mixed or separate upon cooling. Additionally, there are varying opinions on the miscibility of different waxes and oils.

Contextual Notes

Participants mention various methods for analyzing mixtures, but the discussion does not resolve the effectiveness or applicability of these methods in specific contexts. There are also assumptions about the properties of the substances involved that remain unexamined.

GiTS
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I don't know if I used the right word, it's been awhile since chemistry. If I melted parrafin wax and petroleum jelly would they mix like water and salt? Or would they remain separated?

Also, let's say I had a sample of a mixture of various unknown petroleum based solids and high viscosity fluids. How would I determine the make up of that sample?
 
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GiTS said:
I don't know if I used the right word, it's been awhile since chemistry. If I melted parrafin wax and petroleum jelly would they mix like water and salt? Or would they remain separated?

They would probably be miscible at elevated temperature. As the sample cooled, the parrafin would likely crystallize out somewhat and you would probably have finely-divided wax crystallites embedded within a petroleum jelly (contaminated with some uncrystallized wax) matrix.

Also, let's say I had a sample of a mixture of various unknown petroleum based solids and high viscosity fluids. How would I determine the make up of that sample?

There are many ways. You could determine the crystallinity of the sample by optical methods or by X-ray or even by synchrotron radiation methods. You could separate the sample based on some affinity to a high surface area material like silica gel or alumina which would give you a 'chromatographic' separation. Identification of the relatively pure fractions would be done by other methods like elemental analysis, UV-Vis, NMR or mass spectrometry. There are others as well but you get the idea.
 
chemisttree said:
They would probably be miscible at elevated temperature. As the sample cooled, the parrafin would likely crystallize out somewhat and you would probably have finely-divided wax crystallites embedded within a petroleum jelly (contaminated with some uncrystallized wax) matrix.

Have to disagree with you here, having worked on petroleum jellies developments for about 15 years (what a way to spend your life eh?).

If you mixed together molten paraffin wax and molten petroleum jelly they would mix together completely, in all proportions. This is because petroleum jelly is generally a blend of white liquid paraffin and paraffin wax. By mixing together molten paraffin wax and molten petroleum jelly you are simply adding wax content to the petroleum jelly. So, as the sample cools it will simply form petroleum jelly again, just slightly harder and a little higher in drop melting point.
 
And just why is petroleum jelly not water clear? Could there be wax crystallites embedded within the matrix? I've done a little work myself on wax/oil suspensions, but not 15 years worth.
 
Petroleum jelly is not transparent for the same reason that paraffin wax is not transparent. The wax contains a range of molecular sizes, so the crystal sizes show a fair degree of polydispersity which means that light tends to be scattered by them.

When molten petroleum jelly cools the wax matrix traps the oil in its interstices to create the gel structure; if you add molten paraffin wax to molten petroleum jelly, this wax simply adds to the density of the matrix that would otherwise be formed, so that the light scattering effect is still present.
 
Dear all,
Could you answer this question.
Is there any wxes and oils which are mutually immiscible?
I want to melt a wax in a oil, and then cool-down the system to see wax separate as tiny bubbles in the oil phase (while agitating continuously).
 
lohit said:
Dear all,
Could you answer this question.
Is there any wxes and oils which are mutually immiscible?
I want to melt a wax in a oil, and then cool-down the system to see wax separate as tiny bubbles in the oil phase (while agitating continuously).

Hmmm... I'm not sure about tiny, but beeswax in olive oil will do that to some extent. I wouldn't call that mutually immiscible though, but it seems to match your desired end result. If you want a bigger gradient, you could try parrrafin and something like clarified peanut or sesame oil (be CAREFUL).
 
Dear all
The rule "like disolves like"
you know waxes are not crystals then not recrystalize in the mixture with oil ,like crud oil which composed wax,grease ,oil and variable hydrocarbons.
 
wazani said:
Dear all
The rule "like disolves like"
you know waxes are not crystals then not recrystalize in the mixture with oil ,like crud oil which composed wax,grease ,oil and variable hydrocarbons.

Interesting... so if I take Olive oil, and sesame oil and mix them with heat, I won't be able to see separation during the cooling phase? Hmm.
 

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