Surface Modification Of Poly Ethylene Terephthalate (PET) By UV Solid Laser

The irradiation of UV laser is one of physical methods for surface modification of polymers, which is friendly to the environment. The thesis was aimed to study the surface morphology and physical & chemical properties of Poly (ethylene terephthalate) (PET) fiber irradiated by UV laser. The dyeing property of the irradiated PET fabric was also researched.Scanning electron microscope (SEM) observation revealed the morphological modification of the PET fiber irradiated by UV laser with the appearance of ripples perpendicular to the axis of the fiber. Antistatic property and hydrophilic character of PET fabric irradiated by UV solid laser were greatly improved owing to the increase of the O/C ratio of the UV solid laser irradiated PET fiber’s surface. But whiteness, tensile strength and elongation of the PET fabric irradiated by UV laser decreased adversely. The properties of whiteness, tensile strength and elongation were affected by laser parameters including power, pulse frequency, space between filling lines, valid vector step size, and time delay between valid vector steps etc.X-ray diffraction analysis showed that the crystalline region of the UV laser irradiated PET fiber reduced. The K/S value of the UV laser irradiated PET fabric dyed with disperse dyestuff increased greatly. The dye uptake and relative dye uptake of disperse dyestuff for the UV laser irradiated PET fabrics were improved accordingly. The K/S value and the dye uptake were also affected by laser parameters. When dyeing temperature descended, the UV laser irradiated PET fabric got much deeper shade than the PET fabric untreated by UV laser when they were dyed with the disperse dyestuffs at the same technology and prescription.Compared with color fastness of the untreated PET fabric, color fastness to rubbing and light of the UV laser irradiated PET fabric dyed with disperse dyestuff changed little, while color fastness to washing reduced 0.5 grades. When dyeing temperature was 100℃, the color fastness to washing and rubbing of the UV laser irradiated PET fabric dyed with disperse dyestuff were invariable.