deadpool
Harmless
Posts: 21
Registered: 13-3-2014
Member Is Offline
Mood: No Mood
|
|
Binder issue =(
Hello guys & pyrotechnic gods (or goddess). I have a binder issue. I've read a few post and thought I would give it a try, typically I ended up
wasting a lot of product and created a sticky mess. My method was to use polybutene and methylricinoleate (also tried small amounts of oil). I
created the methylricinoleate via esterification with methanol and caster oil. My product was a liquid, but once cooled turned into a sold mass. I
don't know anything about this product and thought perhaps I made a mistake during the esterification process. I did use sodium hydroxide as the
catalyst, which may have been a mistake. Can anyone confirm if this is the right product? Also am I also correct to assume that total inert
materials shouldn't exceed 10% by weight? I have extreme difficulty getting 10% plasticizer/binder to mix that well.
|
|
|
DubaiAmateurRocketry
National Hazard
Posts: 841
Registered: 10-5-2013
Location: LA, CA, USA
Member Is Offline
Mood: In research
|
|
Umm, what is the majority of that mass?
|
|
|
deadpool
Harmless
Posts: 21
Registered: 13-3-2014
Member Is Offline
Mood: No Mood
|
|
This was the product of the caster oil esterification, guess I should have been more clear on that sorry.
|
|
|
deadpool
Harmless
Posts: 21
Registered: 13-3-2014
Member Is Offline
Mood: No Mood
|
|
answering my own question, comments are welcome!
It looks to me like the sodium hydroxide turned the castor oil into a fat  yup..
just googling showed me methyl ricinoleate is a liquid... dang it. Should have I just used an acid for the esterification? Guess I'll try it again.
|
|
|
Deathunter88
National Hazard
Posts: 508
Registered: 20-2-2015
Location: Beijing, China
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by deadpool  | | It looks to me like the sodium hydroxide turned the castor oil into a fat yup..
just googling showed me methyl ricinoleate is a liquid... dang it. Should have I just used an acid for the esterification? Guess I'll try it again.
|
You used sodium hydroxide for an esterification?! No wonder you got such a weird product. Try the same procedure again but this time try using
concentrated sulfuric acid instead of the sodium hydroxide.
|
|
|
NitreRat
Harmless
Posts: 45
Registered: 22-1-2015
Location: Cyberspace
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Deathunter88 | | Quote: Originally posted by deadpool | | It looks to me like the sodium hydroxide turned the castor oil into a fat yup..
just googling showed me methyl ricinoleate is a liquid... dang it. Should have I just used an acid for the esterification? Guess I'll try it again.
|
You used sodium hydroxide for an esterification?! No wonder you got such a weird product. Try the same procedure again but this time try using
concentrated sulfuric acid instead of the sodium hydroxide. |
Or better still, use sodium methoxide. Maybe even, the more easily made, magnesium methoxide, but I'm not sure about that one.
|
|
|
Microtek
National Hazard
Posts: 830
Registered: 23-9-2002
Member Is Offline
Mood: No Mood
|
|
What you have is likely the sodium soap of ricinoleic acid.
I think you should go back one more step; castor oil is a triglyceride, so you could either make a trans-esterification, or you could liberate the
ricinoleic acid first (eg. by hydrolysis with hydroxide). Then after purifying the fatty acid you can do the esterification with methanol and sulfuric
acid.
[Edited on 8-12-2015 by Microtek]
|
|
|
deadpool
Harmless
Posts: 21
Registered: 13-3-2014
Member Is Offline
Mood: No Mood
|
|
Yea i was suppose to mix the methanol and sodium hydroxide to form sodium methoxide first, and I goobered on that part. Thanks guys for the help!
|
|
|
nux vomica
Hazard to Others
Posts: 267
Registered: 18-7-2013
Member Is Offline
Mood: No Mood
|
|
When I made some recently I used these ratios.
Mix 50ml castor oil 20ml methanol 0.3 grm potassium hydroxide together , stir and reflux at 100°c for 3 hours use a vertical condenser to stop
methanol loss, after 3 hours dilute with h2o and seperate oil layer, dont over agitate oil and water mix or it will take days to seperate because it
goes into an emulsion with the water.
Nux.
[Edited on 9-12-2015 by nux vomica]
|
|
|
deadpool
Harmless
Posts: 21
Registered: 13-3-2014
Member Is Offline
Mood: No Mood
|
|
More questions (feed my brain)
Hello again,
I was wanting some clarification on the hydrolysis reaction that taking place (this laborious process isn't going to be use so don't flame me, I just
want to learn).My current understanding is:
Castor oil is a triglyceride that is mainly comprised of ricinoleic acid. When water is added it the hydroxide anions will attack the triglyceride
and break it down (saccharification?) to 3 x ricinoleic acid molecules.
My questions are: Is sodium/potassium hydroxide required or is it just a catalyst? If it is, how do you prevent the soapy salt forming? Lets assume
that I wanted a high quality product and used the method provided by Microtek. From what I understand from this process I should mix castor oil &
water (perhaps with hydroxide salt) and setup for fractional distillation to yield pure ricinoleic acid in receiving glass.
|
|
|
NeonPulse
Hazard to Others
Posts: 417
Registered: 29-6-2013
Location: The other end of the internet.
Member Is Offline
Mood: Isolated from Reality! For Real this time....
|
|
The hydroxide is the catalyst, and by using only a tiny amount and keeping the temp fairly low 20-25c and you should be able to avoid the
saponification of the oil. I'm not sure about distilling the oil though. In my experience just washing the oil with a little water to remove methanol
any excess catalyst and glycerol formed is sufficient. By putting the product into a measuring cylinder and letting water run through this works for
me while preventing too much loss if an emulsion formed with the water. Further methanol can just be warmed off and the oil dried over a dessicant if
needed. The end result was the nice clear Kind of thin oil suitable for plastics.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
