| Abstract:A amphoteric ring crush strengthening agent MMA/DMC/AM/AA for surface sizing application with good stability and excellent property was prepared through surfactant-free emulsion polymerization with acrylamide (AM), methacryloyl oxygen ethyl three methyl ammonium chloride (DMC), methyl methacrylate (MMA) and acrylic acid (AA) as raw materials, and the synthetic process was optimized. The structure, thermal stability and particle size of MMA/DMC/AM/AA were characterized by Fourier transform spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and Dynamic light scattering (DLS), and the surface morphology of sized and unsized papers were studied by Scanning electron microscope (SEM). Furthermore, effects of AM and MMA contents as well as the mass ratio of AA to DMC on papers’ ring crush index were investigated. It was found that the paper sized with the MMA/DMC/AM/AA was endowed with excellent ring crush strength when w(MMA)=1.5%, m(AA)∶m(DMC)=1.5~2.0, w(AM)=8.5%. The ring crush index of the corrugating medium with 100 g/m2 basis weight was up to 8.68 N·m/g. |
