I have three methoxy sialno ; Aminoethyl , aminopropyl - trimethoxysilane and propylmetaacrylate trimethoxysilane and 3 - aminopropyl - trimethoxysilane
Which of the three and sarabbe better? And how should I choose they?
....Prepared the polyurethane resin (PTMEG, BDO-MDI) trimethoxy silane add to crosslink and cure the point, I added amine catalyst. PH or temperature using metoxysilano changes?Which of the three will be better?
propylmetaacrylate trimethoxysilane (no linking to the polymer)
Both (?) amino leads to crosslinked hybridmatrial (compare to the works of Prof. Loy). My own work is focussed on the water dependent kinetic which will influence your polymer if using silanes.
Why not using a triol?
And please do not use an “amine” catalyst. The amine reactivity is multiple times larger than the one of alcohol leading to polyurea not to polyurethane.
https://www.researchgate.net/profile/Douglas_Loy
Article Analysis of silanes and of siloxanes formation by Raman spectroscopy
Your answer is more confusing, please, write clearly what you expect. If you want to crosslink a thermoplastic polyurethane than you need at least three functional groups onthe crosslinker and you have to calculate the formulation accordingly. In case you use an tris-(aminoalkyl)silan you have to avoid other amines such as catalysts or to form ureas as otherwise the reaction path will run out of order and produce some side reaction products such as biurets or splitting products of the silan due to increased temperature.
But this is a guess about your reaction, you should be really precise.
Thanks a lot, before I used aminoalkyl trimethoxysilane with mercury catalyst, but now we can not use more mercury, for what used a catalyst based on amine. you have any advice to give for the catalyst? polyol is : (PTMEG90%+ BDO 10%)
The silanes named will not crosslink the polyurethane.
To catalyze the classic urethane reaction is best performed by tin compounds such as dibutyl tin dilaurate or dioctyltin dilaurate (the latter conforms with toxicity regulations) or with dioctyltin-bis(thioglycolic acid 2-ethylhexylester) if you want to delay the action of catalyst into higher temperature regions (>45°C). Amines are in such cases not the primary choice as they may interfere with side reactions or the next step of synthesis.
In fact I need to delay the reaction about 2 or 3 minutes (at least point gel 2-3 minutes). Ultimo catalyst did not try, where can i find , can you help me?
In this case metoxy silane is not used for the lattice?
If you need a longer gel time you should indeed use a delayed action catalyst such as the named tin sulphur organics but also special amines could be of use; the Performance Chemicals HGmbH of Hamburg (Germany) provides any of these types, check the internet at www.polyurethanes.de
By using alkoxysilanes you will never be able to produce crosslinks. If you want to use these you have to perform a sol gel reaction within the polymer so that the inorganic gel is able to react with excess isocyanate groups forming the networks.
What lattice do you want to produce? This seems to be possible only when you form crystalline structures, either organic, inorganic, or hybrid.
Thank you for your kindness and answer me with attention
The last catalyst meant what she advised ; dioctyltin-bis(thioglycolic acid 2-ethylhexylester. I'm basically looking for a catalyst that acts like diphenyl mercury decanoate.(this is toxic that we can not use more).This catalyst gave me good gel time and also good time hardening intempetaruta 140 ° c.
And then I do not have to use alkoxysilano advice, I tried to eliminate, but the direction seems not complete.
Based on our experience with mercury catalysts I repeat the recommandation to use the tin compounds with delayed action, they will behave very similar to the mercury catalyst you used. You may ask Performance Chemicals HGmbH at Hamburg for a sample of PC CAT T16.
Before I mentioned the PC CAT T16 to you I made sure it is available and on stock at Performance Chemicals HGmbH (Hamburg). It is as well contained in their latests product list.
I have received PC T16 cat, but very active, with little percentage, the reaction was very fast ... since I do not have technical I can ask of you, tell me the name of this chemical produced?
by the way, the catalyst may have effects on the resin? such as felessibilità character, strength and dureza?
The catalyst is dibutyltin-bis(2-ethylhexyl-thioglycolate) It has in general no effect on strength, feasibility or hardness, but may in case of slow action reduce the hardness on the Shore scale by 2 or 3 points
If it is still too actiove you may add a drop of acetylacetone
In fact, another catalyst stagnio, I've tried it, with trade name xk k-kat-604, more controllable, about 60 seconds gel point, but before reaching gel point I need to put in the zirconium resin and glass powder . and then a type of glue, to hold together the powder grains.
but I do not know how much resistance i will have ?
How can I measure the resistance of such a product?
Thanks again for your kindness, always answer me precisely
T 16 is : 4,4-diotil-3,5 ditia-4-stannatetradecanonat ....then sulfur somewhat annoying, for what I was looking for the same family but do not have this annoyance.
By the way you have no idea to measure the strength of this product.
The investigations into the effect of this catalyst have not been published but are subject of several patents by Gert Neumann or Lothar Thiele. The sulfur does not have any adverse effect. The catalyst was specially developed aiming at artifical kidneys as the sealants of the cellulose acetate fibres. Measurements of the kinetics were made in solvents, see L. Thiele, Monatsh. Chem. 123 (10), 875-882 (1992). OTS 16 is delayed up to ca. 45°C, increasing the temperature will lead to a catalytic effect similar to that of stannous octoate.
Hi dear Gerhard, the catalyst pc cat T16, not gone well, I provoto different ways ..... but I try always a catalyst based on tin percentage but more 'low possible.This is possible?