Sciencemadness Discussion Board

Celluloid for art?

Hockeydemon - 30-5-2013 at 01:23

Okay I've been looking around, and I found out that celluloid is (or was) used as a ivory substitute. You can still buy it online. So how do I get a product similar to this celluloid pen. Obviously I will have an inferior product, but I think it would be a neat project.

I need to nitrate some cellulose - my understanding is this is done with nitric acid (red fuming sufficient?), and sulfuric acid (catalyst?). Since I don't want this for pyrotechnics what sort of ratio would be advisable? What should my source of cellulose be? Is there anything I can do to increase the product's stability?

This product is then plasticized with camphor? I initially wanted to synthesize camphor from turpentine, but I came to the conclusion I lack the equipment, and knowledge to undertake such a task. Which is why I was going to buy these camphor granules online.

How is the nitrocellulose actually plasticized? Is it really as simple as making a solution with the camphor granules, and placing the nitrocellulose in the solution?

Since to my knowledge that is what will eventually produce celluloid how do I change it's aesthetic properties? As in how do I get the product to resemble the celluloid pen initially linked?

I have no problem reading - I just need some direction to material to read. Or is this just a complete waste of my time?

Nitrocellulose

chemcam - 31-5-2013 at 09:19

Quote: Originally posted by Hockeydemon  

I need to nitrate some cellulose - my understanding is this is done with nitric acid (red fuming sufficient?), and sulfuric acid (catalyst?). Since I don't want this for pyrotechnics what sort of ratio would be advisable? What should my source of cellulose be? Is there anything I can do to increase the product's stability?


Yes, I have done it with nitric acid as low as 50% but you need more sulfuric acid to handle the excess water of the low percent HNO3, also the lower the percent the longer the nitration time. I prefer to use >70%. You only need to use RFNA or WFNA if you want the hexanitrate for pyro/detonation. Most common source of cotton is 100% cotton balls, the name brand ones. I have had great success with the round cotton pads as well and I actually prefer those because they fit perfect in 100mL beakers and allow for quicker, more thorough nitration.

To increase the storage stability you must be sure to neutralize every molecule of acid, that is most important part and most difficult, acid can hide in/on the fibers so it is a good idea to rip the cotton open and soak in bicarb solution over night with stirring. Optionally, store it in the dark in a vacuum sealed container/bag or inert atmosphere. I would also keep it below room temp. and in the dark.

I don't know about the plasticizing of NC as I have never done it. I have dissolved NC in acetone before to coat onto fuses and it is plastic-like when it starts to evaporate, but it doesn't stay like that for long.

If you need more info about actually making nitrocellulose or cellulose hexanitrate you can u2u me, I have made both successfully countless times.

Bot0nist - 31-5-2013 at 10:01

hexanitrate...

I haveread this term as well, and was corrected by rosco bodine. A molecule of cellulose can be nitrated only tris, IIRC. ~14% N is as high as it gets. fully nitrated cellulose. Me and him went back and forth on it. Im sure you can find the thread if you search.

chemcam - 31-5-2013 at 11:11

Yeah I have heard that too but I have never seen an actual reference stating it was either right or wrong as I'm sure you have seen it written both ways as well since you thought this too.

I suppose a more correct way to say this is the higher percentage your HNO3 the better your NC will come out. But that isn't really what I have seen in practice.. I have gotten all % HNO3 to work the same way as >90% HNO3 as in an instant flash with no residue but for some reason not all will detonate.

I also suppose it varies depending on who you learned from or what books you have.

Edit: If somebody has proof one way or the other please upload a scan.

[Edited on 5-31-2013 by chemcam]

Bot0nist - 31-5-2013 at 11:48

Impact ytesting is a great way to determine if you have a fully nitrated product, IIRC. As it approches 14% N it will det reliably from hammer on anvil strikes In my experiance. I often nitrate the product twice with salt/acid mix. Search "simple synthesis of cellulose hexanitrate" for my write up, and following conversation with rosco, henning, and blasty. A very informative thread...