芴酮引发光接枝改性LDPE膜的研究

采用紫外光引发接枝表面改性的方法,以芴酮(FL)为引发剂,在低密度聚乙烯(LDPE)薄膜表面上接枝丙烯酸(AA)、甲基丙烯酸(MAA)、丙烯酸甲酯(MA)、甲基丙烯酸甲酯(MMA)、丙烯酰胺(AM)等单体,以赋予薄膜表面新的化学性质.考察了引发剂浓度、紫外光的辐照时间、辐照强度、单体种类对LDPE薄膜接枝程度的影响.结果表明,在一定范围内,增加芴酮浓度,可以提高单体的接枝率,但当芴酮浓度达到5%时,接枝率反而下降.延长辐照时间至4 min和提高紫外光的辐照强度达100 W/m2,均有利于接枝反应的进行.不同单体在LDPE膜上的接枝能力与单体的活性、单体与基材的相容性等因素有关.接枝后,LDPE与水的接触角下降程度不仅与单体在膜上的接枝量有关,还与接枝单体的亲水性能密切相关.

SURFACE PHOTOGRAFTING OF FUNCTIONAL MONOMERS INITIATED BY FLUORENONE ON LDPE FILMS

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.