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Xrpdguy
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Solubility of natural resin
Hello guys, for one of the my researches i need to disolve natural resin. The resin is from Cherry and Plum tree. I have tried to disolve it in abs.
Ethanol, n-Hexane, THF, Acetone, but none of these solvents helped me. 
Do you have any recomendition? The only condition is that solvent need to be suitable for IR Spectroscopy (without halogens e.g. CCl4, please).
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Ubya
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acetone and diethyl ether should work, keep in mind that tree resin is slow to dissolve, so you should heat the solvent and agitate with magnetic
stirring even for a few hours
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Xrpdguy
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Quote: Originally posted by Ubya  | | acetone and diethyl ether should work, keep in mind that tree resin is slow to dissolve, so you should heat the solvent and agitate with magnetic
stirring even for a few hours |
I tried with all solvents but on room temperature.
Which temperature you recommend? I am afraid of damaging the structure of resin.
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Ubya
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Most plant resins are composed of terpenes. their boiling points are over 100°C, so even heating acetone to its boiling point shouldn't produce big
losses
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Boffis
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@ Xrpdguy, The "resins" from Prunus species (cherries, plums etc) are not strictly resins but gums and they are composed of polysaccharides. When
fresh they are soluble in water but on exposure to air and light they harden and become completely insoluble in anything that doesn't decompose them.
I have tried hydrolysing cherry gum with dilute hydrochloric acid acid and while it is slow it works. Concentrating the liquor, neutralizing the
excess acid and then adding ethanol or methanol causes a sugar or mixture of sugars to crystallize out. Since you can prepare furfural (my interest)
from these sugars in poor yield (c 20%) they must contain at least a proportion of some pentose. I am sure there is plenty of info out there on the
composition of cherry and other gums. I have just never had the inclination to search for it.
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unionised
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It seems they dissolve in water.
https://pubs.acs.org/doi/abs/10.1021/ie2014179
https://www.ncbi.nlm.nih.gov/pubmed/22701057
Not usually ideal for IR spectroscopy
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Magpie
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I would suggest turpentine. If you can't find this try some other terpene.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Xrpdguy
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| Quote: Originally posted by Boffis | | @ Xrpdguy, The "resins" from Prunus species (cherries, plums etc) are not strictly resins but gums and they are composed of polysaccharides. When
fresh they are soluble in water but on exposure to air and light they harden and become completely insoluble in anything that doesn't decompose them.
I have tried hydrolysing cherry gum with dilute hydrochloric acid acid and while it is slow it works. Concentrating the liquor, neutralizing the
excess acid and then adding ethanol or methanol causes a sugar or mixture of sugars to crystallize out. |
In the beggining of the project i have used peroxy-hydrochloric acid and the resin was disolved within 10minutes but I think that the structure of
the resin was degradated by using highly concentrated acid and peroxide (without heating).
I have determined the structure of pure resin in solid state by IR but now I want to determine the structure of the solution of the resin also with
the IR. Do you think that the structure will be the same or changed?
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DrScrabs
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I did use water only to dissolve cherry gum, then vacuum filter (not fritted filter)
Its a disease called Gummosis
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/gummosis
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/cank
ers/gummosis-of-fruit-trees.aspx
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Xrpdguy
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Can you describe a whole method? Which temperature you used?
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DrScrabs
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No I´m sorry I can´t describe something professional, it was a fun project to replace gum arabic in iron gallus ink and it worked out.
But I can do my best to share my little experience
I harvested the birght amber colored gum (appx 50g) wich was not dry and with as little visible impurities(dirt, insects, bark etc) and put it in a
clean marmelade glass and filled it with dH2O to the top, closed it put at a dark place and let it dissolve at roomtemp until the viscosity did not
increase (4 days for me). Don´t let it stay too long maybe, because as I was writing I remembered a glass sitting in my basement and I just opened it
and smelled a faint odour of alcohol, but this one was forgotten for about two months+ (unfiltered, yeast?).
So when the viscosity does not increase I vacuum filtered trough a buchner funnel and I was left with a slight dim soln. Maybe some particles made it
trough.
Gravity filtration takes like forever so I don´t expect a soxhlet to work. Also I have no clue how elevated temperatures do effect the composition of
the gum, I´ll boil some these days the see what happens visually. I also tried to keep it away from oxygen as good as possible.
Hopefully this helps you a little, if you do need some samples I got a big sick cherrytree in my garden.
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Xrpdguy
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| Quote: Originally posted by DrScrabs | No I´m sorry I can´t describe something professional, it was a fun project to replace gum arabic in iron gallus ink and it worked out.
But I can do my best to share my little experience
I harvested the birght amber colored gum (appx 50g) wich was not dry and with as little visible impurities(dirt, insects, bark etc) and put it in a
clean marmelade glass and filled it with dH2O to the top, closed it put at a dark place and let it dissolve at roomtemp until the viscosity did not
increase (4 days for me). Don´t let it stay too long maybe, because as I was writing I remembered a glass sitting in my basement and I just opened it
and smelled a faint odour of alcohol, but this one was forgotten for about two months+ (unfiltered, yeast?).
So when the viscosity does not increase I vacuum filtered trough a buchner funnel and I was left with a slight dim soln. Maybe some particles made it
trough.
Gravity filtration takes like forever so I don´t expect a soxhlet to work. Also I have no clue how elevated temperatures do effect the composition of
the gum, I´ll boil some these days the see what happens visually. I also tried to keep it away from oxygen as good as possible.
Hopefully this helps you a little, if you do need some samples I got a big sick cherrytree in my garden. |
I am very sure that resin is insoluble in water maybe you have got a resin from the tree in the moment before the whole process of polymerisation has
been ended. In that Period Even it is very short you can dissolve resin into water but mainly solution will be full of polysaccharides.
Thank you for replying every information is priceless.
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Xrpdguy
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| Quote: Originally posted by Ubya | | acetone and diethyl ether should work, keep in mind that tree resin is slow to dissolve, so you should heat the solvent and agitate with magnetic
stirring even for a few hours |
Today I have tried with acetone because it is more polar than diethyletre and has higher b.p.
With stirring and heating (~60°C), after 1.5h a resin was in a state of "chewing gum". I used about 2ml of the solvent.
Do you know some " more powerful" polar solvent? 
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DrScrabs
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Maybe DMSO, nitroethane or acetonitrile?
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Magpie
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Try limonene, which can be obtained from lemon, orange, grapefruit, and lime rinds (squeeze them to get the oil). Also, there is a commercial product
for removing tree resin from cars, etc. It is "Dissolve-It" or something similar.
The single most important condition for a successful synthesis is good mixing - Nicodem
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DrScrabs
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| Quote: Originally posted by Xrpdguy |
I am very sure that resin is insoluble in water maybe you have got a resin from the tree in the moment before the whole process of polymerisation has
been ended. In that Period Even it is very short you can dissolve resin into water but mainly solution will be full of polysaccharides.
Thank you for replying every information is priceless. |
Just saw you reply and you´re right I think, for the ink it was important to have water soluble stuff and the darker hard parts of the resin are
insoluble but they become softer, that´s why I did not use fritted stuff.
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Xrpdguy
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| Quote: Originally posted by Magpie | | Try limonene, which can be obtained from lemon, orange, grapefruit, and lime rinds (squeeze them to get the oil). Also, there is a commercial product
for removing tree resin from cars, etc. It is "Dissolve-It" or something similar. |
As I said the solvent need to be suitable for ir spectroscopy. Are you sure that limonene can a vapourize enough good and enough quick before the
determination?
I dont want any peeks of other compounds in the sample.
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Boffis
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My experience is that once prunus gums have hardened they are insoluble. If finely ground they absorb water a little and swells and it is possible
that a portion actually dissolve, that is certainly the impression I get from some of the papers I have seen following a quick google search
yesterday. These papers (one attached below) show that these gums are complex polymers of pentoses, hexoses and glucouronic acid, they are therefore,
basically, very complex hydrophillic polyesters that continue to polymerise after they have exuded from the tree. The end product is insoluble in
water and I suspect all less polar solvents. If you wish to characterise them there are numerous papers that describe methods of doing this. Most rely
on some form of hydrolysis, either partial or total, with or without prior derivatisation with say dimethyl sulphate or the like.
So I don't think your current line of attach is going to be very fruitful. What sort of mull are you trying to use? Is it possible to grind the gum
with NaCl or KBr and make a pressed disc or an oil mull?
Take a look at this paper for some ideas or just search "hydrolysis of cherry gum" in google
Attachment: 224a248.pdf (3.5MB)
This file has been downloaded 460 times
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Magpie
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I suggest:
1. dissolve the resin in a terpene (limonene or turpentine).
2. extract the resin into water.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Xrpdguy
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| Quote: Originally posted by Boffis |
. If you wish to characterise them there are numerous papers that describe methods of doing this. Most rely on some form of hydrolysis, either partial
or total, with or without prior derivatisation with say dimethyl sulphate or the like.
So I don't think your current line of attach is going to be very fruitful. What sort of mull are you trying to use? Is it possible to grind the gum
with NaCl or KBr and make a pressed disc or an oil mull?
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if I do hydrolize partial or total I will break the polymer chains and that is not my goal. I did before in the some of the steps in this project a
reaction by peroxy-hydrochloric acid and resin can be very easily disolved.
But hydrogen-peroxide cuts the long chains into smaller and change the structure of resin.
A depertment of organic chemisty on my faculty has a device which allows me to determine the structure without KBr disc or oil. Its Nicolet IS 10
(ftir). The resin or some compound of it can be recorded directly.
Because of that i am not into making discs or search about them.
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Xrpdguy
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Nothing! Nothing! Nothing!
I just cannot dissolve fuckin' resin in any solvent (except limonene cause its hard to obtain it( a lot of time and peels)).
Acetone, n-Hexane, THF, acetonitrile.... And nothing!
I tried on boiling point of solvents and still nothing. Crashing into pieces is very hard job (cause resin is hard as a rock), but anyway its
useless.
Any recomendition? Please :'(
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DrP
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Score up the resin first.... leave it to soak in the solvent for about a week - see if it has touched it after that.
\"It\'s a man\'s obligation to stick his boneration in a women\'s separation; this sort of penetration will increase the population of the younger
generation\" - Eric Cartman
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Herr Haber
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I dont think this will be of any help seeing you tried almost everything but...
I dissolved colophony with IPA. It took a very long time at ambiant temperature and was much faster in warm solvent.
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Xrpdguy
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| Quote: Originally posted by DrP | | Score up the resin first.... leave it to soak in the solvent for about a week - see if it has touched it after that. |
It stayed about 5 days in Acetone and THF (in separated vials, not a mixture of solvents). Nothing happened, and after evaporisation of solvents the
resin became much harder than before.
Yesterday i tried with domestic cleaner. It has only three ingredients (Ethanol 70%, isopropyl alcohol 3% and chlorhexidinedigluconate 0.57%) onits
boiling point and the resin was partly dissolved.
Do you think that Ethanol and isopropyl mixture can help?
Or any other mixture?
[Edited on 12-9-2018 by Xrpdguy]
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Boffis
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Your problem is that you don't read or listen to the answers you get.
Cherry gum and related gums are NOT resins like colophony or copal and once hardened they are highly cross linked polyesters that are not soluble in
any simple solvent. End of story.
They are only soluble once at least some of the ester groups are hydrolyzed to give smaller units and these are then soluble in water and possibly
other polar solvents like methanol.
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