Sciencemadness Discussion Board

What plastic is this Rubbermaid container made of?

UncleJoe1985 - 28-1-2015 at 14:45

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Rubbermaid 21 Cup Premium Food Canister

I want to use it for a chlorate or perchlorate cell, but I don't see any resin code.

It's very transparent (tiny bit less than acrylic). It also has a purple hue when you look at the edges and a barely noticeable purple hue when looking through it. That makes me think it's polycarbonate. But according to Rubbermaid, they used to use polycarbonate in the premium containers but no longer.

Obviously, this BPA free formulation would be a valuable discovery, but roughly does anyone know what plastic is it most similar too?

There's another container almost exactly like this one but not as transparent. It doesn't have a resin code either but I'm pretty sure it's polypropylene since it's translucent. Polypropylene seems to be a pretty safe choice since according to the Cole Parmer , it's very resistant against chlorides, chlorates, and hydroxides (D for chlorine water is worrisome)

subsecret - 28-1-2015 at 16:44

Is there a symbol on the bottom, like a recycling triangle with a number inside? Look up the number and that'll be your plastic.

Dr.Bob - 28-1-2015 at 16:49

Some clear containers are made of polymethylpentene, which is water resistant but not so good for organics. But without some sort of confirmation, I would look it over carefully for a mark on the bottom or something on the label. Polyproylene is usually only translucent but holds up well to most chemicals.

Zombie - 28-1-2015 at 17:09

Here is the rubermaid page for the product you pictured... http://www.rubbermaid.com/Category/Pages/ProductDetail.aspx?...

There is a blue link titled "Need more information"
That link takes you to the contact us page. I would ask them.

Bert - 28-1-2015 at 17:15

Eastman "Tritan" brand copolyester.

http://en.m.wikipedia.org/wiki/Copolyester

http://www.eastman.com/Literature_Center/M/MBS632.pdf

And Eastman does not care to disclose exactly what this resin may be!

http://ws.eastman.com/ProductCatalogApps/PageControllers/MSD...
Quote:

While unpublished studies in 2008 and 2009 by Oregon State students suggest BPA does not leach from polycarbonate plastic under extreme conditions, BPA is not the only component of plastics which can mimic estrogen and act as an endocrine disruptor.[13] Unfortunately, plastics made of BPA-free Tritan were later found to leach other estrogenic chemicals in a cell-based assay.[14] Eastman Chemical, the manufacture of Tritan will not disclose any information about this product or its composition.[15]


However, some people are willing to hazard an educated guess...

http://sbi.oregonstate.edu/education/su09interns/Dornath.pdf



[Edited on 29-1-2015 by Bert]

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Etaoin Shrdlu - 28-1-2015 at 17:58

Quote: Originally posted by Bert  
Eastman "Tritan" brand copolyester.

http://en.m.wikipedia.org/wiki/Copolyester

http://www.eastman.com/Literature_Center/M/MBS632.pdf

And Eastman does not care to disclose exactly what this resin may be!

Sure they do. http://www.ncbi.nlm.nih.gov/pubmed/22343188

"Eastman Tritan™ copolyester, a novel plastic from Eastman is manufactured utilizing three monomers, di-methylterephthalate (DMT), 1,4-cyclohexanedimethanol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCD) in various ratios."

UncleJoe1985 - 29-1-2015 at 00:42

Quote:
[It's] Eastman "Tritan" brand copolyester.


Very educated guess indeed. There doesn't seem to be a lot of common transparent plastics (Acrylic (polymethlamethacrylate), Butyrate (cellulose acetate butyrate), Lexan (polycarbonate), and PETG). Acrylic doesn't seem likely since the container isn't as crystal clear. Polycarbonate also seems to be ruled out since by definition it's made with BPA, contrary to the label, unless Rubbermaid found a way to guarantee there's no unreacted BPA. Personally, I didn't hear much about the BPA leaching controversy until today nor get why people are making such a fuss. So that leaves Butyrate and PETG which Tritan is similar too. Plus the container is made in America, so naturally Eastman would be a supplier.

I'll see how well it holds up. According to this table, PET seems pretty bad against NaOH. But according to the attached chart, the NaOH concentration shouldn't go beyond 0.1% by weight assuming the pH doesn't go above 12.5.
Quote:
Some clear containers are made of polymethylpentene

A high melting point (235C) and chemical resistance make it sound expensive. I wouldn't mind that for just 1 container.

I just had a great idea. Is there a way I can order some polymethylpentene pellets or wire and feed it into a 3D printer to make my own chemically inert and transparent container? Do all plastics become transparent when melted like? It would be awesome if Teflon can be made transparent.





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[Edited on 29-1-2015 by UncleJoe1985]