Cross-linking Polyvinyl Alcohol

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The discussion revolves around creating a food-safe, stringy slime for a movie project, similar to the slime seen in "Charlie and the Chocolate Factory." The original idea involved using polyvinyl alcohol (PVA) cross-linked with disodium tetraborate, but this is not suitable due to safety concerns. Participants suggest exploring alternative edible compounds for cross-linking PVA, such as various starches, gums, and soluble polymers. Guar gum and carrageenan are mentioned as potential options, but the effectiveness of methylcellulose is questioned due to its yogurt-like texture. Carboxymethyl cellulose is also discussed, though its clarity and viscosity properties are noted. A suggestion is made to use methocel for viscosity combined with boiled okra extract for stringiness, highlighting mucilage as a promising idea. Overall, the conversation emphasizes the challenge of achieving the desired slime properties using safe, edible ingredients.
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Some friends and I are working on a movie, and we need a very stringy clear slime; like is produced with polyvinyl alcohol cross-linked with disodium tetraborate. Only we need it to be food-safe, so we can't simply use that. Is there another way to cross-link PVA into a stringy slime using edible chemicals?
 
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A few days ago I watched the movie Charlie and the Chocolate Factory, and therein was a slime that had pretty much the mechanical properties I'm looking for, and was edible. It wasn't transparent, but milky translucent. And green -- but that's just food coloring. What could it have been made of?

Is cross-linking polyvinyl alcohol using an edible compound just not possible, at least yet?
 
It probably wasn't PVA-based. It could be any number of starches, gums or soluble polymers. Have you seen Guar gum by itself or Carageenan? How about plain Methocel or Ethocel?
 
OP ,

I happen know that PVA with suitable macromers in water formulation would have the properties that you've mentioned ; also you can experiment with saturating water with the PVA and perhaps PVAc in water .
 
Thanks, guys. :smile:

Re: Methylcellulose

I got some of it weeks ago, and tried it out. It's not the right texture. It's not stringy at all, but more like a yogurt.

The other stuff mentioned looks like it will work.
 
Are you referring to Carboxymethyl cellulose ? From what I remember this is not exactly clear in water except at lower concentrations . It can get viscous as it is used as a lubricant .
 
Use the methocel to provide the base viscosity and blend with an extract of boiled okra for the stringiness.
 
I see that galactose dialdehyde can be used as http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFF-43HJRBJ-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_version=1&_urlVersion=0&_userid=10&md5=bb39c841992b0482f858b0de5a3ea6bd"

Finding a food grade aldehyde that I would trust will be a problem though.
 
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chemisttree said:
Use the methocel to provide the base viscosity and blend with an extract of boiled okra for the stringiness.

Ah, mucilage - brilliant idea, there. :smile:
 
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GCT said:
Are you referring to Carboxymethyl cellulose ?

I don't think so, but I wouldn't rule out that being what it is. The container just says methylcellulose -- bought it from a special FX supply company.

It looks quite clear in water to me; though if I mix up a really thick batch (a ball of it will hold its shape against gravity, mostly), it's translucent.
 
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