Water retention crystals - organic ?

[Primrose]

Have just dug up my last leeks and was pleased to find that the water retention crystals I dug into the soil in the leek patch last Spring are still there and working effectively, some still entangled in the roots, so they do last a whole season. But I like to grow organically wherever possible so is using them violating my ethics?

[Lyn]

I also wondered about this, and have been assured that they are biodegradable and quite O.K. to put on the compost where they decompose eventually, or leave in the ground. I am still trying to find out what they are made of, though.

[alan refail]

What are they made of? They don't sound likely to be very organic.

Alan

[madasafish]

The crystals are probably coming from the "super absorbent layer" found in most disposable diapers. This layer consists of paper fluff and a chemical absorbent called sodium polyacrylate. Sodium polyacrylate is an amazing water absorber -- it can absorb 200 to 300 times its weight in tap water (even more if the water is distilled) and hold it in a gooey gel.

Sodium polyacrylate is a polymer, meaning that it consists of chains of identical units (monomers). The monomer for sodium polyacrylate is:


--CH2--CH(CO2Na)--
It is a pretty cool polymer -- shake the crystals out of a new diaper (or buy the crystals at a garden center) and add water to them. Pretty amazing!

There is concern in certain circles about the use of sodium polyacrylate next to a child's skin. The concern is often used as an argument against disposable diapers. This diaper page talks about the issue briefly and will give you a sense of what people are concerned about.

These links will help you learn more:

Diaper Polymer
AP Chemistry Polymer Project - polymer experiments
Plant Gel - The other common use for sodium polyacrylate is as a water-retaining gel in houseplants.
Toxic Shock Syndrome and Tampons - The diaper page mentioned above talks about TSS and hints at a relation between TSS and sodium polyacrylate. This page offers a much clearer explanation of TSS.

[PAULW]

A sodium polyacrylate superabsorbent polymer made by bulk polymerization and characterized as described herein is a superior gelling agent when provided at a suitable concentration in a gelled anode for an alkaline electrochemical cell. Suitable gelled anodes, alkaline electrochemical cells containing such gelled anodes, and methods for making and using same are also described.
Glad I am not organic I would not put this stuff in my lottie.

[alan refail]

Certainly doesn't sound organic
As for "diapers", we used to call them "nappies", they were made of Terry towelling and they were washed - after scraping off the shit . Disposable nappies are a serious environmental threat, so I suppose the crystals fall into the same category.

Alan (old(ish) git, and getting grumpier by the hour )

[Primrose]

Oh well, if any of the gel crystals remain entangled in the leek roots after I've eaten them, at least I won't need to wear a nappy to catch the contents when they come out at the other end !!

[oldherbaceous]

Dear Primrose, i suppose thats one way of looking at it, that did make me smile.