Surface Graft Polymerization of Binary Monomers Maleic Anhydride/n-Butyl Vinyl Ether on the Polypropylene Film via Two-Step Method

Abstract

ABSTRACT:Maleic anhydride (MAH) was readily grafted onto polypropylene (PP) film by means of introducing the electron donor monomer n-butyl vinyl ether (n-BVE), via two-step method. In the first step, the semibenzopinacol (SBP) groups were introduced onto the film surface under UV irradiation, and they were subsequently detected by both gravimetric method and UV spectra. In the second step, the "dormant" SBP groups were activated and cleaved from the substrate under heat, resulting in the formation of surface free radicals (grafting points) and the immediate initiation of graft polymerization; the temperature required for this process was found to be around 80• C. The grafting resultsshow that the grafting yield (Y g ) of two-step method can be much higher than that of one-step method, and that the novel electron donor-acceptor grafting system is much more effective than that of pure MAH. Properly speaking, the Y g value could reach as high as 180% within 1 h, and the density of polar groups (D p ) on the substrate was 49.5 µmol cm −2 correspondingly. Besides, the maximum Y g can be always attained at 1:1 molar feed ratio of MAH to BVE, indicating that the facile grafting process is attributed to the formation of charge transfer complex (CTC) between the binary monomers. Another significant result is that the good affinity of solvent towards substrate, and especially the desirable solubility for the graft chains are both preferable to heterogeneous graft polymerization. In addition, some phenomena characterizing "living" graft polymerization were revealed in this particular grafting system, which is expected to favor the control of the length and chemical structure of the graft chains.

Preparation of Soft Hydrogel Nanoparticles with PNIPAm Hair and Characterization of Their Temperature-Induced Aggregation

“…Over the past decade, extensive investigations in our group have been focused on the development of novel photopolymerization systems. − Reinitiation from dormant sites derived from active hydrogen abstraction of benzophenone (BP) or isopropylthioxanthone (ITX) and coupling of semipinacol or thioxanthpinacol radicals with surface macroradicals have been demonstrated. Through such a reinitiation, free radical polymerizations with living/controlled characteristics were performed, giving rise to the immobilization of monolayered or multilayered nanoparticles on polymer film surfaces .…”

Atom transfer radical polymerization of graft chains onto polyethylene film initiated at tribromomethyl unit introduced by electron beam irradiation

“…Some reports have shown that living radical polymerization allows graft polymerization onto shaped polyolefin substrates without shape changes 22–25. These reports show that a lengthy process is necessary before the introduction of initiators for ATRP graft polymerization 22–25. None of these reports have discussed the number of introduced initiators.…”

Two‐stage grafting onto polyethylene fiber by radiation‐induced graft polymerization and atom transfer radical polymerization

“…The introduction of graft chains onto polyolefin substrates such as polyethylene (PE) or polypropylene (PP) by living radical polymerization has been known to be difficult, because these are chemically inert surfaces when compared to silicon surfaces. ATRP initiators have been introduced onto the surfaces of the polyolefin substrates by ultraviolet irradiation and block copolymer chains grafted onto the substrates 18–21. However, the structures of the monomers for this method are limited, and it is particularly difficult to graft water‐soluble monomers, because the surface of the polyolefin substrate is hydrophobic.…”