Preparation and properties of ion‐exchange membranes prepared by the radiation‐induced grafting of a styrene/acrylic acid comonomer onto low‐density polyethylene

Abstract

The preparation of ion-exchange membranes by the direct radiation grafting of acrylic acid and styrene onto low-density polyethylene was studied. The effects of the grafting conditions, such as the comonomer composition and concentration and the irradiation dose, on the grafting yield were also investigated. The swelling behavior, ion-exchange capacity, structural changes, and thermal properties of unsulfonated and sulfonated membranes were studied. The crystallinity decreased with grafting and sulfonation, but the chemical and thermal stability was improved by sulfonation. The removal of some toxic heavy-metal ions-Cd 2þ , Pb 2þ , and Zn 2þ -was studied. Some factors that influenced the metal-ion uptake were studied. The metal-ion-uptake results showed that the membranes could be used for the adsorption of the investigated metal ions and had an affinity toward Pd 2þ ions in a mixture. The regeneration of the membranes was carried out by a treatment with 1M HNO 3 , and the membranes were used several times with high efficiency. Thus, the membranes may be suitable for pervaporation or vapor permeation to separate wastewater because of their hydrophilicity.

Estimation of surface properties of grafted layers formed on low‐ and high‐density polyethylene plates by photografting of methacrylic acid and acrylic acid at different monomer concentrations and temperatures

“…In fact, the grafting technique is much attractive in modifying surface and functional properties of the polyolefin materials such as low‐ and high‐density polyethylene (LDPE and HDPE) and polypropylene (PP). Many initiation methods of surface grafting have been developed, e.g., chemical reagents,20 electron beam,21, 22 γ‐ray,23, 24 plasma,25, 26 and UV‐irradiation 27–29. Among them, the combined use of UV initiation with a hydrogen‐abstraction‐type photosensitizer is one of the most attractive procedures 30–32.…”

In Commodity Plastics

“…Regeneration of the ion -exchange membrane was easily performed with a 1 M HNO 3 treatment. The ion exchange membranes were amenable for removing Cd 2+ , Pd 2+ , and Zn 2+ ions from wastewater [7] .…”

Adhesion of surface‐grafted low‐density polyethylene plates with enzymatically modified chitosan solutions

“…Surface modification of polyolefin materials by grafting techniques has been also widely investigated by many researchers. The grafting polymerization was initiated by plasma treatment14–17 or by irradiation with UV18–21 and Co 60 radiation 22‐26. Because the energy of UV rays emitted from a 400W high‐pressure mercury lamp used as an energy source of the photografting technique is lower than those of other grafting techniques, the location of grafting is restricted to the outer surface region of the polymer substrates and the surface properties are modified at lower grafted amounts.…”