Synthesis and long-term stability of acrylic acid and N, N-methylene-bis-acrylamide radiation grafted polypropylene fibers

New carboxyl ion-exchange fibers prepared by acrylic acid (AA) and N, N-methylene-bis-acrylamide (MBAA) monomer grafting to polypropylene (PP) fibers based on the method of gamma-rays pre-irradiation in air followed by a Mohr's salt redox initiation of grafting reaction were studied. Grafting degree, homopolymer quantity, monomer conversion and grafting efficiency were determined. FTIR spectroscopy was used to establish the nature of the grafted fibers. The thermal stability of the materials was investigated based on DSC analysis in N-2/O-2 mixture. The long-term stability during 6-8 years of storage was examined by the measurement of the tensile strength and the elongation at break of the fibers, and the chemical oxygen demand in water extracts as well as in the oxygen uptake experiments. The influence of some factors on the useful life of the grafted fibers was studied: a MBAA cross-linking, exposure to day light, the Fe (III) residue presence, a grafting reaction temperature. It was found that small amounts of the adsorbed Fe (III) ions increase the deterioration rate of the grafted fibers, while small amounts of MBAA delay this negative process.

Automated summary

The study focuses on the preparation and characterization of new carboxyl ion-exchange fibers, utilizing different factors to investigate their long-term stability. Results show that factors such as MBAA cross-linking, exposure to light, Fe(III) residue presence, and grafting reaction temperature can significantly impact the useful life of the grafted fibers.