Via the process of photografting surface modification by UV light

fluorenone (FL) was employed as an initiator in the grafting reaction of acrylic acid (AA)

acryamide (AM)

methylacrylic acid (MAA)

methyl acrylate (MA) and methyl methacrylate (MMA) onto the surface of LDPE films for introducing new chemical properties to the film surface.In this study

influences of the initiator concentration

UV light irradiation time

UV light irradiation intensity as well as the types of functional monomers on the grafting yield of LDPE films were investigated respectively.Within a certain range

the results showed that raising the fluorenone concentration would lead to the increasing of the grafting yield

however

when the fluorenone concentration reached 5%

the grafting yield decreased.The grafting polymerization was fully promoted by increasing the light irradiation intensity up to 100 W/m2 and prolonging the UV light irradiation time to 4 min.Grafting ability of different types of monomers on LDPE films was concerned with parameters such as activity of monomers

compatibility of monomers with the matrix and so on.After successful grafting of functional monomers

the changes of water contact angle of the grafted LDPE film were related to the grafting yield of monomer on the film as well as the hydrophilicity of the applied monomers.