Preparation of Acrylic Acid Grafted Polypropylene Nonwoven Fabric by Photoinduced Graft Polymerization with Preabsorption of Monomer Solution

We improved photoinduced graft polymerization by absorbing the monomer solution onto the substrate (Ab-type) instead of immersing the substrate in the monomer solution (Im-type) before photoirradiation to yield a more practical and effective grafting system. With this system, acrylic acid (AA) was effectively grafted onto polypropylene (PP) nonwoven fabric. The maximum degree of grafting obtainable was restricted by the amount of monomer preabsorbed onto the PP fabric. However, we effectively enhanced the degree of grafting by increasing the monomer concentration, adding trimethylolpropane triacrylate (TMPTA) to the monomer solution, and repeating the photoirradiation with supplementation of the monomer solution. The net availability of the monomer for graft polymerization was 50%, or greater; this increased to 90% or greater with the addition of TMPTA and was much higher than for conventional Im-type photografting (<= 13%). Fourier transform infrared spectra, scanning electron microscopy morphology observations, and the adsorption-regeneration properties confirmed that the PP-g-AA fabric prepared by the improved Ab-type photografting method had comparable qualities to those of fabric prepared by conventional Im-type photografting. Thus, the improved Ab-type photografting system provides potential for the preparation of graft adsorbents on a large scale at a competitive cost with a continuous reactor, such as a conveyer belt system, instead of a batch reactor. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 387-397, 2009