Retraction notice to “Synthesis of polypropylene fabric with sulfonate groups” [Radiat. Phys. Chem. 77 (2008) 503–510]

Surface chemical modification of polypropylene fiber waste by H2SO4: Mechanistic investigation and application as cation‐exchange adsorbent

“…In a first step, H 2 SO 4 attacks the surface of PP fibers producing sulfonic groups. The formation of sulfonic groups have been observed before 1, 4…”

“…For example, high‐energy electron beam irradiation is necessary to create radical reactive points on the PP surface. These dangling radicals can then react with different molecules such as sulfonated styrene (CH 2 CHC 6 H 4 SO 3 Na), acrylic acid (CH 2 CHCOOH) Mohr's salt ((NH 4 ) 2 Fe(SO 4 ) 2 .6H 2 O) and styrene 1. Other examples of radical‐based functionalization have been reported using thiol reaction with the unsaturation end of the PP chain2 and the reaction with maleic anhydride initiated by radicals 3…”

Comparative investigations of radiation‐grafted proton‐exchange membranes prepared using single‐step and conventional two‐step radiation‐induced grafting methods

“…Recently, a few research groups have reported radiation grafting of SSS onto a limited number of polymer substrates including high‐density polyethylene, polypropylene and poly(tetrafluoroethylene‐ co ‐hexafluoropropylene) apparently for separation applications. Because of poor SSS grafting kinetics caused by the incompatibility between highly ionized hydrophilic sulfonic acid groups and hydrophobic polymer backbones leading to very low grafting levels, acrylic acid (a co‐monomer) is grafted prior to or with SSS to promote the grafting reaction 15–22. Grafting of SSS without acrylic acid onto aromatic polyamides (nylon MXD6) under controlled conditions was also recently reported by Li et al 23…”

Acid‐synergized grafting of sodium styrene sulfonate onto electron beam irradiated‐poly(vinylidene fluoride) films for preparation of fuel cell membrane

“…Recently, few research groups have turn their attention to develop a single‐step radiation induced grafting route for preparation of sulfonic acid containing polymers to substitute the conventional route (grafting and sulfonation) by radiation grafting of sodium styrene sulfonate (SSS) onto few polymer substrates such as high density polyethylene (HDPE), polypropylene (PP) and poly(tetrafluoroethylene‐ co ‐hexafluoropropylene) (FEP) apparently for separation and purification applications 11–22. A summary of previous studies of radiation induced grafting of SSS is presented in Table I.…”