Preparation and Characterization of Polyethyleneimine/Sorbitan Monooleate Blended Polypropylene Antifogging Films

In this paper, a twin-screw extruder was used to blend polypropylene (PP) with polyethyleneimine (PEI) to produce hydrophilic PP. Maleic anhydride-grafted polypropylene (PP-g-MAH) and Span-80 were added to improve compatibility between the two phases and promote the dispersion of PEI within the PP matrix. The mechanical properties of the modified PP were tested using a universal testing machine and an Izod impact tester. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to analyze surface functional groups and fracture morphology, respectively. Surface wettability, transparency, and Span-80 migration rate were evaluated through contact angle measurements and UV-Vis spectrophotometry. Additionally, antifogging performance was tested using hot fog and cold fog methods. The results show that when the mass ratio of PP-g-MAH is 5 wt%, PEI is 20 wt%, and Span-80 is 5 wt%, the mechanical properties of the modified PP are significantly improved. The tensile strength reaches 36.2 MPa, a 1.4% increase; the elongation at break reaches 1151%, an 88.7% improvement; and the impact strength is 9.9 KJ/m2, a 106.3% increase. Furthermore, the modified PP exhibits a surface contact angle of 14°.