Synthesis and polymerizations of new metal chelating monomers from alkyl α‐hydroxymethacrylates

Abstract

Two new diethyl iminodiacetate-containing monomers (EBMA-ID and CMAC-ID) were synthesized through the reaction of ethyl a-bromomethacrylate (EBMA) and a-chloromethacryloylchloride (CMAC) with diethyl iminodiacetate (ID). The hydrolysis of the ethyl ester groups with potassium hydroxide gave two chelating monomers with potassium salt of iminodiacetic acid (EBMA-IDA-K 1 and CMAC-IDA-K 1 ). The homopolymerization and copolymerization with 2-hydroxyethyl methacrylate (HEMA) of EBMA-ID and CMAC-ID were investigated by photodifferential scanning calorimetry at 408C using 2,2 0 -dimethoxy-2-phenyl-acetophenone (DMPA) as initiator. The monomers showed very low homopolymerization reactivity which may be attributed to the steric effect of N,N-disubstituted methacrylamides, the presence of allyl amine group that can undergo degradative chain transfer and the bulky ID group close to the double bond. Also, addition of these monomers to HEMA decreased polymerization rate and conversion with fraction added. EBMA-IDA-K 1 and CMAC-IDA-K 1 were copolymerized with acrylamide in water using 2,2 0 -azobis(N,N 0 -amidinopropane) dihydrochloride (V-50) initiator. Here also, it was observed that the incorporation of the synthesized monomers into acrylamide reduced both the rate of polymerization and conversion. The copolymers were characterized by 1 H-NMR spectroscopy, thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The UV-visible and TGA spectra confirmed that the synthesized monomers showed chelating ability for Ni 12 and Cr 13 .

Highly porous, water‐swellable, and reusable chelating polymeric gels for heavy metal ion removal from aqueous waste

“…The structures of the resins were characterized and confirmed by FTIR spectroscopy (Figure 3). The FTIR spectrum of the IDAESR15 showed a characteristic ester carbonyl stretching band at 1742 cm −1 and the IDASR15 showed the characteristic carbonyl stretching bands of carboxylate salt at 1600 and 1399 cm −1 corresponding to its asymmetric and symmetric stretching 35,36 . The carbonyl stretching of methyl ester groups at 1742 cm −1 completely disappeared in IDASR15, which confirmed the complete hydrolysis of all ester groups.…”

“…It was found that IDAESR15 with ester groups showed a one‐step degradation pattern due to the decomposition of the polymer chains and revealed good thermal stability with an onset degradation temperature of 340 °C at 5% weight loss (T 5 ). IDASR15, generated by base hydrolysis, showed a two‐step degradation pattern, with an initial weight loss of 15% extending from room temperature (30 °C) to 200 °C attributable to the loss of moisture from IDASR15 36 . In the second step, the weight loss was due to the decomposition of the polymer chains which revealed good thermal stability with an onset degradation temperature of ~400 °C.…”

“…IDASR15, generated by base hydrolysis, showed a two-step degradation pattern, with an initial weight loss of 15% extending from room temperature (30 C) to 200 C attributable to the loss of moisture from IDASR15. 36 In the second step, the weight loss was due to the decomposition of the polymer chains which revealed good thermal stability with an onset degradation temperature of ~400 C.…”