Methacrylic acid

About: Methacrylic acid is a research topic. Over the lifetime, 13058 publications have been published within this topic receiving 173201 citations. The topic is also known as: α-Methacrylic acid & 2-Methylacrylic acid.

Chemical and Electrostatic Association of Various Metal Ions by Poly(acrylic acid) and Poly(methacrylic acid) As Studied by Potentiometry

Abstract: Potentiometric titrations have been performed for poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMA) in solution in the presence of different metals (Ca, Mg, Zn, and Cu) by titrating with KOH without additional salt. For the Me/PAA system, experimentally obtained apparent dissociation constants (pKa) appear to decrease in the initial part of the titration curve, which was found to be most pronounced in case of Cu. This was also found for the Cu/PMA system. For all systems studied, an increase in pKa was observed at higher degrees of dissociation. Analytical expressions for the change in apparent pKa upon ionization have been derived on the basis of counterion condensation theory taking into account both electrostatic and chemical binding of counterions of different valences. Taking also into account the effects of the flexibility of the polymer, the agreement between calculated and experimentally obtained data is certainly satisfying for the larger part of the titration curve. The agreement is comp...

Copolymerization of methacrylic acid with methyl methacrylate by SET‐LRP

Abstract: Single-electron transfer living radical polymerization (SET-LRP) has developed as a reliable, robust and straight forward method for the construction well-defined polymers. To span an even larger variety of functional monomers, we investigated the copolymerization of methyl methacrylate with methacrylic acid by SET-LRP. Copolymerizations were catalyzed by Cu(0)/Me6-TREN and performed in MeOH/H2O mixtures at 50 °C. The SET-LRP copolymerizations of varying methacrylic acid content were evaluated by kinetic experiments. At low (2.5%) and moderate (10%) MAA loadings, the copolymerizations obeyed perfect first order kinetics (kpapp = 0.008 min−1 and kpapp = 0.006 min−1) and exhibited a linear increase in molecular weights with conversion providing narrow molecular weight distributions. The SET-LRP of MMA/25%-MAA was found to be significantly slower (kpapp = 0.0035 min−1). However, a reasonable first-order kinetics in monomer consumption was maintained, and the control of the polymerization process was preserved since the molecular weight increased linearly with conversion and could therefore be adjusted. This work demonstrates that the copolymerization of methacrylic acid by SET-LRP is feasible and the design of well-defined macromolecules comprising acidic functionality can be achieved. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

Selective recognition of 2,4,5-trichlorophenol by temperature responsive and magnetic molecularly imprinted polymers based on halloysite nanotubes

Abstract: Fe3O4/Halloysite nanotube magnetic composites (MHNTs) were firstly prepared via an effective polyol-medium solvothermal method, and then the surface of the MHNTs was endowed with reactive vinyl groups through modification with 3-(methacryloyloxy)propyl trimethoxysilane (MPS). Based on the MHNTs-MPS, temperature responsive and magnetic molecularly imprinted polymers (t-MMIPs) were further synthesized by adopting methacrylic acid (MAA) and N-isopropylacrylamide (NIPAM) as the functional monomer and temperature responsive monomer, respectively. The as-prepared t-MMIPs were characterized by FT-IR, TEM, TGA and VSM, which indicated that the t-MMIPs exhibit magnetic sensitivity (Ms = 2.026 emu g−1), magnetic stability (especially in the pH range of 4.0–8.0) and thermal stability and are composed of an imprinted layer. The molecular interaction between 2,4,5-trichlorophenol (TCP) and MAA was investigated by 1H-NMR spectroscopy and ultraviolet absorption spectroscopy, which suggest that hydrogen bonding may be largely responsible for the recognition mechanism. The t-MMIPs were then applied to selectively recognise and release TCP molecules at 60 °C and 20 °C, respectively. The maximum amount of binding at 60 °C was 197.8 mg g−1 and 122.6 mg g−1 for t-MMIPs and temperature responsive and magnetic non-imprinted polymers (t-MNIPs), respectively. At 20 °C, about 32.3%–42.7% of TCP adsorbed by t-MMIPs was released, whereas 25.3%–39.9% of TCP was released by t-MNIPs. The selective recognition experiments demonstrated the high affinity and selectivity of t-MMIPs towards TCP over competitive phenolic compounds, and the specific recognition of binding sites may be based on the distinct size, structure and functional group to the template molecules.

Imprinted hydrophilic nanospheres as drug delivery systems for 5-fluorouracil sustained release.

Abstract: Molecularly imprinted hydrogel nanospheres as devices for the controlled/sustained release of 5-fluororacil in biological fluids were synthesized employing one-pot precipitation technique as the polymerization method. Methacrylic acid as a functional monomer and ethylene glycole dimethacrylate as a cross-linker were used in polymeric feed. Morphological and hydrophilic properties were determined by scanning electron microscopy and water content measurement, and recognition and selectivity properties of spherical molecularly imprinted polymers were compared with the spherical non-imprinted polymers, both in organic (acetonitrile) and water media. Finally, in vitro release studies were performed in plasma simulating fluids.