Synthesis, characterization, and functionalization of superadhesive melamine formaldehyde polyvinylpyrrolidone resins doped with metallic and graphene oxide nanoparticles for better industrial applications

Structure of melamine-formaldehyde-polyvinylpyrrolidone (MFP) polymer resin prepared with melamine, formaldehyde, polyvinyl pyrrolidone (PVP) at pH = 7 was determined using FTIR, H-1 NMR, and C-13 NMR spectroscopy. Physicochemical properties and thermal stability were analyzed with dynamic light scattering (DLS) and thermogravimetric analysis (TGA) respectively. 1H NMR spectra showed doublet at 3.13 and 3.17 ppm due to neighboring electron-deficient nitrogen and electron density of bridged carbon atoms. The C-13 NMR have infrared vinyl chain, melamine, and pyrrolidone peak for C = O, 48.72 ppm depicts C atom of -CH2 between O and C atoms. Peak at 17.50 ppm inferred terminal -CH3 of vinyl chain. FTIR stretching frequencies at 3426.38 and 2915.5 cm(-1) vibrations depicted -N- (tertiary amine), and -CH2 group of - (CH2 - CH2)(n) vinyl chain of PVP, respectively. New band at 2350 cm(-1) inferred -CH2 of formaldehyde attached with O atoms of PVP. MFP was doped with Fe3O4 (magnetic nanoparticles = MNPs), CaS (calcium sulfide), CaO, and graphene nanoparticles for reinforcement. Encapsulated Fe3O4-MFPR, CaS-MFPR, graphene oxide-MFPR are compared with MFPR alone. TGA inferred higher stability of Fe3O4-MFPR, CaS-MFPR.