## 1 Introduction  
Membrane technology has been actively developed and used in a wide range of applications in fuel cells, water treatment, and biotechnology [1; 2; 3]. The fuel cells are the most important among those applications because they are effective devices for alleviating carbon dioxide emission from combustion such as cars and power plants. The energy sources of fuel cells are hydrogen and methanol, which do not originated from fossil fuel, making fuel cells environmentally friendly [4; 5]. Moreover, energy efficiency of fuel cells is higher than conventional energy devices such as diesel and gasoline engines operating on fossil fuel. Emergence of fuel cells has been led by discovery of new materials and new technologies. There are several types of fuel cells, but anion exchange membrane fuel cells (AEMFCs) provide advantages compared to other fuel cells. Basically, AEMFCs use anion exchange membranes as separator, which transport hydroxide from cathode side to anode side, provide potassium hydroxide as electrolyte, and convert hydrogen directly to electrical current. Their advantages include the following: (1) oxygen reduction kinetics happen more readily in alkaline conditions than in acidic conditions, and thus the amount of highly expensive catalysts used such as platinum can be decreased; (2) their operating temperature is relatively low, in the 60 to 90 \({}^{\circ}\)C range; (3) corrosion problems are alleviated under alkaline conditions; and (4) hydrogen, the fuel for AEMFCs, can be replaced by liquid fuels such as methanol, ethanol, and propanol due to high anode potential to oxidize C-C bonds in alcohol [6]. However, the anion exchange membranes (AEM) in AEMFCs have poor chemical stability in high pH environments, so their performance can be limited. To be more specific, cation sites, which are generated from quaternized ammonium groups on the membrane, can be decomposed as the hydroxides move through the membrane. Hoffman degradation (E2 elimination), E1 elimination, and nucleophilic substitution (S\({}_{\text{N}}\)2) can occur to break up quaternized amines when ammonium groups are exposed in hydroxide solutions [7; 8; 9]. Therefore, ion conductivity and alkaline stability gradually decline in alkaline environment. Glycidyl methacrylate monomer, vinylbenzyl chloride monomer, and divinyl benzene monomer have been studied as alternatives to improve chemical stability for anion exchange membrane [10; 11]. Glycidyl methacrylate (GMA) monomer contains acrylic and epoxy, and provides good flexibility in polymer structure. The epoxy groups in this monomer can react with other functional groups such as carboxyl, hydroxyl, and amine groups. GMA monomer has been known to lead a significant increase in polymerization rate and improve the wet-strength of the resulting polymer [12; 13]. Vinylbenzyl chloride (VBC) is also used as a polymer reactant and polymeric support. VBC is a dual functional monomer with C=C and C-Cl structures, which means that VBC may be polymerized by itself and also react with amine groups. As for divinyl benzene (DVB), there is a need for its polymer structure to be held because the solubility of polymer prevents its application in AEMFCs. It was reported that the components of DVB, acting as cross-linker among monomers, affects ion conductivity, thermal stability, and chemical stability [14]. All monomers (GMA, DVB, and VBC) are oil-phase, meaning that these monomers can be mixed. Non-woven PET was introduced to anion exchange membranes due to its chemically inert property and high tensile strength. In addition, non-woven PET has good permeability due to high porosity. Benzoyl peroxide (BPO) can initiate radical polymerization among GMA, DVB, and VBC due to the C=C structure. There has been much research on polymerization of GMA-DVB, VBC-DVB, and GMA-VBC, respectively [15; 16]. The conductivity of copolymer of poly (methyl methacrylate-co-butyl acrylate-co-vinylbenzyl chloride) reached 8.2 \(\times\) 10\({}^{-3}\) S\(\cdot\)cm\({}^{-1}\) at80 \({}^{\circ}\)C [17].