Dear Mohammad Ranjbar, would you please give the chemical structure of PP carboxylic acid. My Regards

In case you don't have an idea about the chemical structure, then think to use hydrolyzed polymethacrylamide instead of polyacrylamide. Best of Luck in your work

I hope that the following links maybe useful.

https://patents.google.com/patent/CN102936311A/en

https://doi.org/10.1021/acsomega.0c01198

https://hal.archives-ouvertes.fr/hal-02479341/file/natural-weathering-of-hemp-fibers.pdf

Dear Mohammad Ranjbar;

Polyacrylamide (PAA) can be hydrolyzed into a carboxylic acid by heating at high temperatures in dilute and concentrated aqueous solutions and suspensions. The most efficient procedures for performing hydrolysis are during acrylamide polymerization in aqueous solutions and emulsions. Hydrolysis under acidic conditions requires strong mineral acids such as hydrochloric, sulfuric, phosphoric, etc.) and polysulfonic acid. In alkaline hydrolysis PAA is heated with boiling aqueous solution in the presence of alkalis, carbonates and bicarbonates of alkali metals, etc.). Please see attached files.

With my best regards

Hi;

I also hope that the links below will be useful to you in your research work

https://doi.org/10.3390/membranes8020020

https://patents.google.com/patent/US4945136A/en

https://www.cheric.org/PDF/KJChE/KC16/KC16-4-0505.pdf

https://www.cheric.org/PDF/KJChE/KC16/KC16-4-0505.pdf

My regards

The following paper may be helpfull.

https://doi.org/10.1039/JR9490002732

Dear Mohammad Ranjbar, since the conversion of amide groups to carboxylic acid or carboxylate ones is never acieved at 100% in both polyacrylamide and polymethacrylamide, it is quiet wise enough to work directly with polymethacrylic acid polymer. Hope this will be more helpfull. Best of Luck