Study On Photografting Modification And Electroless Copper Plating Of PET Films

Pd-free electroless copper plating of PET films after surface modification was the purpose of this paper. In this paper, two mainly researching parts are included. Surface photografting modification of PET films is the first part, including vapor-phase surface photografting, liquid-phase photografting and solid-phase photografting. The second part is electroless copper plating of the surface photografting PET films.Acrylic acid was used as grafting monomer in vapor-phase photografting modification. The effect of immersing time, concentration of photoinitiator, grafting time and concentration of acrylic acid on vapor-phase photografting was discussed, and the optimum values of the above influencing factors were determined:immersing time was30-45min, concentration of photoinitiator was1.2g/L, grafting time was12min, concentration of acrylic acid was50wt.%. At last, the conclusion that acrylic acid could be grafted to PET films successfully was demonstrated by FTIR-ATR.Acrylic acid, acrylamide and maleic acid were used as grafting monomers in liquid-phase photografting modification. The effect of grafting time and concentration of monomer on liquid-phase photografting was discussed, and the optimum values of grafting time and concentration of monomer were12min and8wt.%respectively. Grafting degrees of different monomers were compared in the condition of optimum values, grafting degrees of acrylic acid, acrylamide and maleic acid were in descending order. FTIR-ATR was used to prove that acrylic acid, acrylamide and maleic acid had been grafted to PET films. Finally, characteristics between vapor-phase photografting and liquid-phase photografting were compared, and three conclusions were obtained:(1) Monomers used in liquid-phase photografting were more than that used in vapor-phase photografting.(2) In generally speaking, grafting degree of liquid-phase photografting was higher than that of vapor-phase photografting.(3) Monomers used in vapor-phase photografting could be reused, but not as used in liquid-phase photografting.Solid-phase photografting had been carried out on the foundation of vapor-phase and liquid-phase photografting, acrylamide and maleic acid were used as the monomers. The weight of PET films was not increased after solid-phase photografting attributed to the self-polymerization of the monomers with the irradiation of UV light. FTIR-ATR was shown that acrylamide could be grafted to PET films by solid-phase photografting, but not as maleic acid.The grafting PET films were submitted to electroless copper plating after vapor-phase photografting. The effect of activated time, concentration of AgNO3, pH value of the plating bath and temperature of the plating bath on deposition rate was discussed, and the optimum values of the above influencing factors were determined:activated time was40s, concentration of AgNO3was1.3g/L, pH value of the plating bath was12.6, temperature of the plating bath was40～45℃. Finally, untreated and metallized PET films were analyzed by XRD and SEM respectively.