The effect of plasma polymerization of silicon compounds on the properties of biaxially oriented polypropylene (BOPP)

In this study, hexamethyldisiloxane was polymerized on the biaxially oriented polypropylene films by low-pressure radio frequency (RF) plasma. The samples were polymerized by using RF plasma in the frequency range of 13.56 MHz at the different polymerization times. The surface properties and chemical structure of samples were examined by contact angle measurement, atomic force microscopy, scanning electron microscopy and Fourier transformation infrared (FTIR). Also, the scratch behavior and the mechanical properties of samples were evaluated by using SPM lithography. In this work, some distinguishing changes were observed in properties of polymerized samples in comparison with raw sample. Results showed that the scratch resistance increased by prolonging polymerization time, whereas the surface energy decreased dramatically. It can be inferred from SPM and FTIR data that there is a direct relationship between scratch resistance and chemical composition of samples. Scratch resistance is mostly affected by silicon compounds deposited on the samples. Plasma polymerization causes changes in the chemical structure and surface properties of samples.