The Surface Modification And Characterization Of Polymer By Grafting Polymerization

This paper studied the surface modification and characterization of polymer by UV-irradiation and plasma induced grafting polymerization.Firstly, this paper studied the surface modification of polymer by UV-irradiation induced grafting polymerization. Acrylonitrile or acrylamide monomer was grafted onto the surfaces of nylon non-woven by UV-irradiation under the initiator of benzophenone, and it was confirmed by ATR-FTIR and SEM analysis. The influence of grafting reaction condition to the grafting ratio was also investigated. The grafting ratio increases along with the prolonging of UV-irradiation time. The grafting ratio was proportion to the increase of monomer concentration. With the increase of initiator concentration, the grafting ratio increased first and then decreased. The influence of grafting ratio to the swelling ratio and dyeability was also investigated. The swelling ratio increases steadily with the increase of grafting ratio. The dyeability of nylon non-woven was improved after grafting. The separation performance of nylon non-woven to Cu2+ was also improved after grafting. The thermal stability of the grafted sample was characterized by TGA. The thermal stability decreases after nylon grafted with acrylonitrile or acrylamide. The char residue of the grafted sample increases comparing with that of virgin nylon. The experimental char residue is greater than the theoretical. It indicates that the grafted layer not only can be charred in the thermal degradation stage, but can also promote charring of the substrate polymer. The result is consistent with the prolonging of ignition time, which indicated that the flame retardancy of nylon non-woven can be improved by UV-irradiation induced grafting polymerization.Acrylamide monomer was grafted onto the surfaces of PET non-woven by UV-irradiation under the initiator of benzophenone, and it was confirmed by ATR-FTIR analysis. The influence of grafting reaction condition to the grafting ratio was also investigated. The grafting ratio increases along with the prolonging of UV-irradiation time. The grafting ratio was proportion to the increase of monomer concentration. With the increase of initiator concentration, the grafting ratio increased. The influence of grafting ratio to the swelling ratio and dyeability was also investigated. The swelling ratio increases steadily with the increase of grafting ratio. The dyeability of PET non-woven was improved after grafting. The separation performance of PET non-woven to Cu2+ was also improved after grafting. The ignition time of the grafted sample was investigated. The time of ignition was extended along with the increase of grafting ratio. The result indicated that the flame retardancy of PET non-woven can be improved by UV-irradiation induced grafting method.Secondly, this paper also studied the surface modification of PET by grafting with acrylonitrile through plasma-induced grafting polymerization. The grafting conditions of reaction temperature, monomer concentration, reaction time and solvent had great influence to the grafting ratio. The higher the reaction temperature was, the higher the grafting ratio was. The grafting ratio increased sharply when the reaction temperature reached boiling temperature of the reaction solution. The grafting ratio was proportion to the increase of monomer concentration. The grafting ratio increases along with the prolonging of reaction time. The solvent had great influence to the grafting reaction. The grafting ratio increased with the volume ratio of water to alcohol when using methanol and water as mixed solvent for PET grafting polymerization with acrylonitrile. If the volume ratio is zero, that is to say, only using ethanol or isopropanol as the solvent, the grafting ratio has maximum value. The grafting ratio decreases when the solvent contains water. It was confirmed that acrylonitrile monomer was grafted onto the PET surface by ATR-FTIR and SEM analysis.