Abstract:Using polystyrene as macroinitiator and poly-siloxane acrylate ester as monomer, polystyrene-polydimethyl siloxane copolymers (PS-PDMS) were prepared by atom transfer radical polymerization. The obtained polymers were spin-coated on the surface of polyethylene terephthalate (PET) film to investigate the effect of different siloxane contents in the copolymers on properties of the polyester films. The structure of polysiloxane acrylate monomers and copolymers with styrene were characterized by 1H-NMR and FT-IR-ATR. The results show that the styrene copolymers were successfully prepared. The molecular weight of the polymers was characterized by GPC. The results show that the molecular weight of the polymers is close to the designed molecular weight, and the molecular weight distribution coefficient is less than 1.4, indicating that the reaction is controllable. The refractive index of the polymers characterized by UV-visible spectrophotometer shows that the refractive index of the polymers increases with the decrease of the content of siloxane in the block polymers. The FE-SEM results show that the porous honeycomb structure is formed on the surface of the polyester films, which effectively improves the light transmittance of the films. After coating with the copolymer, the hydrophobicity and optical performance of the polyester films are significantly improved compared with pure polyester film. When the content of siloxane is 19.6%, the refraction index of PS-PDMS copolymer decreases to 1.38, the light transmittance of the modified films increases from 88.0% to 92.6%, and the water contact angle reaches 120°.