Paul,
It may be sooner than that. Look at
http://www.cotronics.com/vo/cotr/ea_ultratemp.htm . Three types of epoxy are
listed there with 600K and 700K operational limit. I checked one of them. It
is an epoxy with a ceramic filler. It will not cure at room temperature, it
requires oven curing. After curing it looks like a black brick and it seems
to be hight temp resistant. But I did not make any measurements of strength.
Cotronics might have all that info.
Jerzy

Yes but how will we know for sure until ten years go by?

Paul Lamar

Krasinski wrote:
Paul,

There are two main terms in decomposition of  plastics.

One is thermal excitation of molecule to an excited state with a higher reactivity where it can react with oxygen, water, or
break apart, and the rate of decay is given by the Arhenius law. According to Arhenius the  decay  rate ~ exp(E/kT), where E is
the energy of the excited reactive state, and T is temperature.   Only the excitation energy  of the material and temperature
define the decay rate here, and the lifetime can be extended by reducing temperature, which is not very practical. However, if
the stuff survives high temperature that means E is very large, and the lifetime at room temperature would be huge due to the
exponential form.

The other term is photodecomposition, and that one is probably faster for most of plastics, we all know what happens with
plastics left outside in the full sun light.  This term is manageable. Just block UV and photodecomposition is stopped. So with
a proper selection of adhesive in terms temperature resistance (i.e. in terms of E), and  proper blocking  of UV it is probably
not a very bad prognosis even for 10 years.

Jerzy

I am so disappointed in the strength of the plastics I see in ten year
old cars that I will believe it when I see it ten years from now if I am still
alive :)

Paul Lamar
 
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