Sound useful enough stuff to crosspost this.

A subset of Nonexisteum. comes to town:

Geopolymers

Are very easy to make as
They handle easily and
Do not require high heat,
Have a higher heat tolerance than organic,
Will not burn at all,
Mechanical properties are as good as those of organic composite,
They resist all organic solvents, and
Are only affected by strong hydrochloric acid.


        R


----- Original Message ----- =

From: "Moldau" <moldau@iprimus.com.au>
To: "Arocket List" <arocket@exrocketry.net>
Sent: Tuesday, September 12, 2006 9:27 PM
Subject: Re: [AR] castable and chemically inert


Geopolymer resin may be exactly what you are looking for.

 http://www.geopolymer.org/

Taken from this site
"These mineral polymers are flexible ceramics which transform like =

plastics
at low temperatures, ceramic composite made at room temperature or =

thermoset
in a simple autoclave.  Geopolymerization is a geosynthesis (a =

reaction that
chemically integrates minerals) that involves naturally occurring
silico-aluminates.  Chemically they form a Potassium =

Poly(sialate-siloxo)
cross linked network.


Geopolymer composites have three main properties that make them =

superior to
ceramics, plastics, and organic composite materials.

First:
Geopolymers are very easy to make, as they handle easily and do not =

require
high heat.

Second:
Geopolymeric composites have a higher heat tolerance than organic
composites. Tests conducted on Geopolymer carbon-composites showed =

that they
will not burn at all, no matter how many times ignition might be =

attempted.

Third:
The mechanical properties of Geopolymer composites are as good as =

those of
organic composites. In addition, Geopolymers resist all organic =

solvents
(and are only affected by strong hydrochloric acid)."

One of the local universities has been bragging about this stuff in TV
advertisements.

http://announce.curtin.edu.au/release2005/C19405.html

They have produced a type of cement but there are other forms and
applications for Geopolymers.  They may have a lot of uses in =

rocketry.

I may have to try casting some nozzles with this stuff.

Burnsie
1000GTR ZG1000-A7 "The Bismarck"


> -----Original Message-----
> From: J. H. Dom [mailto:john.dom@pandora.be]
> Sent: Sunday, 3 September 2006 8:50 PM
> To: 'Moldau'
> Subject: RE: [AR] castable and chemically inert
>
>
> My question is related to casting a heat sink connecting peroxide =

> with a
> hot plate. The hotplate temperature being preferably much hotter =

> than the
> boiling point of the peroxide.
> a castable non-metallic material which can
> contain and is inert to concentrated hydrogen peroxide up to 160=B0 C =

> (320>
> Alternatives are plaster (brittle!) and ... sand after restraining =

> the
> tubing with a metal frame.
> If they next need to be fired in a kiln,
> which I suppose is necessary for e.g. the cordierites, I cannot use =

> them.
> The material is to be caste around FAP tubing with peroxide as a =

> heat
> sink and restrainer. The peroxide 'll not reach the cast.
>



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