Surface modification of polypropylene sheets by UV‐radiation grafting polymerization

Abstract

1,6-Hexanediol diacrylate (HDDA) was grafted onto polypropylene (PP) substrates in the presence of benzophenone (BP) and isopropylthioxanthone (ITX) photoinitiators, and then polyurethane acrylate formulations were coated onto the HDDA-g-PP substrates, using UV radiation. The amount grafted and the grafting efficiency of the polymerizations were determined gravimetrically. The effects of the photoinitiator concentration and the UV radiation intensity on the physicochemical surface properties and the grafting efficiency of the UV-radiation grafting polymerizations were characterized in detail using contactangle measurements, Fourier transform infrared spectroscopy with attenuated total internal reflection, and scanning electron microscopy. The results showed that the amount grafted and the surface polarity of the HDDA-g-PP substrates both increased linearly with increasing BP photoinitiator concentration and UV radiation intensity, and that the addition of a small amount of ITX markedly enhanced both parameters, probably due to photosensitization. The adhesion of the UV-cured coating onto the HDDA-g-PP substrates was evaluated using the crosshatch adhesion test. The results indicated that the amount of HDDA grafted onto the PP substrates should exceed about 1 mmol/cm 2 for satisfactory adhesion with the UV-cured coating.

Photografted polymeric networks based on N‐isopropylacrylamide: Depth profiling by infrared spectroscopy

“…Growing of the grafted linear PNIPA chains ( III ) in the propagation stage [Scheme , reaction 4(a)], which is a primary photografting, can evolve into a secondary photografting [reaction (4b)], once the irradiation period is prolonged and in the presence of a sufficient amount of photoinitiator. In this stage, extraction of a second hydrogen atom by the photoinitiator from the PNIPA chain creates branchings on which the following monomers become attached.…”

Surface Modification of Polymers: Methods and Applications

“…UV grafting step can be performed at any stage of the fabrication process. Cho et al have used UV‐initiated‐grafting and UV‐initiated‐polymerization steps to coat multiple layers of 1,6‐hexanediol diacrylate (HDDA) on PP substrates . Patterned surface modifications can also be achieved with UV graft polymerization by imposing a mask between the surface and the light source (Figure a) .…”

Surface modification of polysulfone hollow fiber membrane for extracorporeal membrane oxygenator using low‐temperature plasma treatment

“…However, further improvement of the hemocompatibility of PSF membrane surfaces is required to extend their biomedical application, because insufficient hemocompatibility impairs functionality and safety through the activation of blood coagulation and immune systems. To improve the hemocompatibility of membranes, many methods have been employed to modify the membrane surface, including chemical modification, UV, ozone exposure, surface coatings, radiation exposure, and plasma treatment …”

“…[5] However, further improvement of the hemocompatibility of PSF membrane surfaces is required to extend their biomedical application, because insufficient hemocompatibility impairs functionality and safety through the activation of blood coagulation and immune systems. To improve the hemocompatibility of membranes, many methods have been employed to modify the membrane surface, including chemical modification, [6][7][8] UV, [9,10] ozone exposure, [11] surface coatings, [12] radiation exposure, [13,14] and plasma treatment. [15,16] Among the various surface modification technologies, low-temperature plasma treatment (LTPT), which is environmentally efficient, has been widely used to modify the surface properties of polymeric membranes.…”