Radiation Grafting for the Functionalization and Development of Smart Polymeric Materials

Abstract

Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the high-energy radiation exposition over the polymeric material. Thus, a microenvironment suitable for the reaction among monomer and/or polymer and the active sites is formed and then leading to propagation to form side-chain grafts. The modification of polymers using high-energy irradiation can be performed by the following methods: direct or simultaneous, pre-irradiation oxidative, and pre-irradiation. The most frequently used ones correspond to the pre-irradiation oxidative method as well as the direct one. Radiation-grafting has many advantages over other conventional methods because it does not require the use of catalyst nor additives to initiate the reaction and usually no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter is focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, the diverse applications of these materials in the biomedical area are also reported, with focus in drug delivery, sutures, and biosensors.

Drug delivery system based on poly(ether‐block‐amide) and acrylic acid for controlled release of vancomycin

“…19,22 The acid groups become ionized and swell when they are in basic pH medium. 19,22 The acid groups become ionized and swell when they are in basic pH medium.…”

“…On the other hand, PAAc is a pH-responsive polymer, which change its swelling behavior by changes in pH medium. 19,22 The acid groups become ionized and swell when they are in basic pH medium. Thus, grafting of PAAc was expected to communicate pH-responsiveness to the PEBA copolymer.…”

“…15 In order to avoid this risk, several strategies, have been investigated to endow medical devices with antimicrobial properties. 19 Using this technique, the degree of functionalization can be tuned by varying radiation conditions such as dose, time, and reaction temperature. 17,18 In this sense, grafting polymerization initiated by the action of gamma radiation is a useful technique for the surface functionalization.…”

“…17,18 In this sense, grafting polymerization initiated by the action of gamma radiation is a useful technique for the surface functionalization. 19 Using this technique, the degree of functionalization can be tuned by varying radiation conditions such as dose, time, and reaction temperature. Also, this technique does not require the use of initiators or additives which may be damaging and difficult to remove.…”

High Performance Anion Exchange Membrane Fuel Cells Enabled by Fluoropoly(olefin) Membranes

“…Recently, radiation‐grafted low‐density polyethylene (LDPE) poly(vinylbenzylchloride)‐based AEMs reported by Wang et al demonstrated a peak power density of 1.45 W cm −2 at 80 °C. However, the radiation grafting of LDPE could lead to possible degradation of the polymer matrix, severely impacting the mechanical strength of the membrane . Additionally no long‐term device performance data were reported for these AEMs …”