Solubility of nylon 6 in formic acid?

You can heat it up and see, or you can leave it for a while and observe as well!

I can tell you with certainty that nylon 6 is soluble in formic acid, but it has to be pure formic acid, not a formic acid solution. In the past, I used formic acid to soak the bottles for polymerization. So it will definitely dissolve.

I suggest you check the manual. When encountering a problem, the first thing to think of should be the manual; don’t rush around frantically looking for a solution. I’ve checked it for you: Available solvents: acetic acid, formic acid, trichloroacetic acid, chlorophenol, phosphoric acid, sulfuric acid, ethyl formate. Wait. . . Solubility unknown. I feel it’s miscible; there’s no need to write it down. Macromolecules are not subject to the same simple Ksp constraints as small molecules.

Formic acid is soluble; heat is required, as its dissolution is very slow at room temperature.

Nylon 6 is soluble in formic acid: lol

It should be able to dissolve; it can do so at room temperature. When we determine the amount of adhesive needed for nylon 6 cord, we use formic acid to dissolve the nylon 6 and then filter out any residual gel that hasn’t dissolved

Guys, I’ve been wanting to ask a question while conducting experiments on nylon ? Nylon 6 can dissolve in formic acid (an 85% formic acid solution). The question is whether it will degrade when dissolved in formic acid, and whether its molecular weight will change. If the dissolution temperature is set at room temperature, will nylon 6 degrade into low-molecular-weight linear polymers, or will it be hydrolyzed (in an 85% formic acid aqueous solution) into the monomer 6-aminohexanoic acid? Could formic acid also react with nylon 6, or with oligomers or 6-aminohexanoic acid, to produce other substances that alter its molecular structure or properties? What is the mechanism by which nylon 6 dissolves in formic acid, and why does it dissolve in it? So is the dissolution of nylon 6 in dimethylformamide the same as that in formic acid? The question is quite basic; I’d be very grateful if the experts could explain it to me. Thank you! ! ! !

An article on {{Research on the Properties of Nylon 6 Solutions with High Relative Viscosity}} states that a 9% formic acid solution at a temperature of 50–60°C can dissolve Nylon 6. However, ordinary Nylon 6 pellets (with a relative viscosity of 3.4) do not dissolve in this 9% formic acid solution. It seems that the behavior varies depending on the specific type; the user will need to discover this for themselves. I hope this is useful to you

I did some searching, and it seems that someone said it is soluble in 90% formic acid: victory:

The reason why nylon polymers possess such excellent strength, friction resistance, and good solvent resistance is that the hydrogen bonds in the nylon amide groups are very strong. I believe that formic acid is able to dissolve nylon because it can break the hydrogen bonds in the nylon amide groups. At the same time, I believe formic acid cannot degrade nylon—when a formic acid solution containing nylon is diluted with water or neutralized with an alkali, all of the dissolved nylon can be precipitated out. With all due respect, may I ask the original poster why you are studying nylon 6? Can DMF (dimethylformamide) also dissolve nylon? Because I am also interested in nylon 6. Last edited by little on 2008-6-30 15:30]

At the same time, I believe formic acid cannot degrade nylon—when a formic acid solution containing nylon is diluted with water or neutralized with an alkali, all of the dissolved nylon can be precipitated out. Are the various properties of the newly precipitated nylon still the same as before?

The melt index of the precipitated nylon remains unchanged, which means that its molecular weight, hydrogen bonds, and so on remain unchanged as well.

I used to work with nylon as well, and I can share with you what I experimented with back then. When working with Nylon 6, I had to use pure formic acid to clean the bottles; therefore, Nylon 6 definitely dissolves in formic acid, and it does precipitate out when exposed to water. As for DMF, I don’t think it can dissolve nylon 6; the biggest advantage of nylon 6 is its hydrogen bonds. Could DMF break those hydrogen bonds? Nylon 6 is fundamentally a linear polymer and cannot be three-dimensional, as it can be processed by melting. Formic acid dissolves nylon 6 by breaking the intermolecular forces, rather than destroying the structure of the macromolecules themselves; otherwise, it would not be a process of dissolution but rather degradation

Dissolution will definitely occur, but degradation probably won’t. Some companies abroad seem to use formic acid to measure its relative viscosity. If degradation takes place, what does the measured viscosity then mean?