A novel poly(vinyl N-furfuryl-N-benzoylthiourea) and its metal complexes: synthesis, properties, and food packaging applications

4-vinyl-N-furfuryl-N-benzoylthiourea monomer (4VBT1) was successfully polymerized using free radical polymerization conditions with high yields and molecular weights, Mn = 674 kDa with 2.0 molecular weight distribution (PDI). Ag(I), Zn(II) and Cu(II) complexes of this polymer have also been successfully synthesized and characterized. The films of polymer (P4VBT1) and its silver complex (P4VBT1-Ag) were evaluated to determine their food preservation properties. Physicochemical and microbiological analyses of the packaged beef with P4VBT1 and P4VBT1-Ag films were carried out on the 1st, 5th, 10th, and 14th days of the storage process. Moisture levels in P4VBT1 and P4VBT1-Ag stayed stable, and no significant pH difference was detected between the groups at the end of the storage period. The beef’s peroxide in P4VBT1-Ag packaging was lower than others at storage end. During storage, insignificant changes were observed in a* values for group B and b* values for groups A (P4VBT1) and B (P4VBT1-Ag). Throughout the storage period, group B demonstrated the lowest levels of total mesophilic aerobic bacteria (TMAB) and total psychrotrophic aerobic bacteria (TPAB). On day 14, it also had the fewest Escherichia coli, but samples showed no statistical difference. By day ten, P4VBT1 and P4VBT1-Ag packaging showed reduced effectiveness in suppressing Coliform bacteria. Utilizing P4VBT1 and P4VBT1-Ag materials for packaging has led to a slowdown in microbial expansion.