is there any specific resins whose working life be at least 10 hours? should i use specific hardener or add a specific matter?
The pot life depends on the curing chemistry, temperature and the presence or absence of catalysts. Amine cured epoxies cure at or around room temperature, anhydrie cured ones at high tempertaure. If the amine is aromatic, it may also cure at higher temperatures. High temperature curing resins usually require catalyst/accelerator. It may also depend on, whether you are using liquid or solid resin. So please specify your system. Cooing may also extend the lifetime.
The pot life depends on the curing chemistry, temperature and the presence or absence of catalysts. Amine cured epoxies cure at or around room temperature, anhydrie cured ones at high tempertaure. If the amine is aromatic, it may also cure at higher temperatures. High temperature curing resins usually require catalyst/accelerator. It may also depend on, whether you are using liquid or solid resin. So please specify your system. Cooing may also extend the lifetime.
Dear Alisa
curing in low temperature increases viscosity of resin and I need resin of low viscosity to fill microcracks of rock samples
Hello Ahmad,
For your application you may have to use some solvent and decrease application the temperature as suggested by Khairiah and Alisa. If you don't want volatiles you may also use a mixture with aliphatic low viscosity epoxy resins. However, they don't have the strength of aromatic ones. After your mixture have diffused in the microcracks you may then postcure at the desired temperature for your system.
If these solutions do not work for you then you will have to consider another type of chemistry. such as unsataturated polyesters or acrylics.
Best wishes and Happy New Year
I may add as a suggestion specialty resins called 3P based on isocyanate/water glass combination, product of Polinvent Ltd. (http://polinvent.com/?page_id=13) designed for various purposes, including injection. The pot life can be varied in a considerably wide range.
Dear Dr Banhegyi
Thank you for valuable comment. I found resin with appropriate viscosity and i change the resin to hardener ratio to change curing time
Dear Dr Guy Havet
Polyester resins cure fast than epoxy resins and as you said the strength of polyester resins is lower than epoxy resins and adding solvent or changing their compounds may cause cracks. thank you so much.
Dear Dr Vladimirov
The lower temperature, the more viscosity. I want to impregnate rock sample of small pores and it is necessary to work with low viscosity resin
There is no way around cooling if you want to retard the polymerisation.
I would add 1,6-Bis(2,3-epoxypropoxy)hexane to lower the viscosity.
@Ahmad. In your answer you mention changing the the resin/hardener ratio to increase the potlife. Please check the physical properties of the hardened resin carefully as if you offset the stoichiometric ratio you may have undercured resins with inferior properties.
Dear Ahmad:
You can perform the impregnation at, say 40C, the viscosity will be OK at this temperature but the yield of reaction if the impregnation process proceeds fast - will be low. Upon impregnation place the sample into freezer.
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