Topic
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.
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TL;DR: In this paper, the esterification of triethylene glycol (TEG) with methacrylic acid (MAA) was carried out over various solid acid catalysts.
Abstract: The esterification of triethylene glycol (TEG) with methacrylic acid (MAA) was carried out over various solid acid catalysts and the results were compared with conventional acid catalysts. Among the catalysts studied, heteropolyacids showed higher activities than the conventional acids. These were attributed to the acidity of the catalysts. A systematic investigation was carried out for the esterification of triethylene glycol with methacrylic acid over phosphotungstic acid without any free radical inhibitor. The effects of catalyst concentration, alcohol/acid molar ratio and temperature were also studied. Parameters such as activation energy, reaction enthalpy and reaction entropy were derived for the above reaction over phosphotungstic acid in the temperature range of 353–383 K. The obtained results were also compared with silicotungstic acid.
77 citations
TL;DR: A stable copolymeric network of PVA was developed with MAA and the prepared hydrogels were highly pH responsive and could be a potential delivery system for colon targeting of 5-FU in colorectal cancers.
Abstract: Background of the Study: The propose of the present work was to develop chemically cross-linked polyvinyl alcohol-co-poly(methacrylic acid) hydrogel (PVA-MAA hydrogel) for pH responsive delivery of 5-Fluorouracil (5-FU). Methods: PVA based hydrogels were prepared by free radical copolymerization. PVA has been cross-linked chemically with monomer (methacrylic acid) in aqueous medium, cross-linking agent was ethylene glycol di-methacrylate (EGDMA) and benzoyl peroxide was added as reaction initiator. 5-FU was loaded as model drug. FTIR, XRD, TGA and DSC were performed for characterization of copolymer. Surface morphology was studied by SEM. pH sensitive properties were evaluated by swelling dynamics and equilibrium swelling ratio at low and higher pH. Results: FTIR, XRD, TGA and DSC studies confirmed the formation of new copolymer. Formulations with higher MAA contents showed maximum swelling at 7.4 pH. High drug loading and higher drug release has been observed at pH 7.4. Conclusions: The current study concludes that a stable copolymeric network of PVA was developed with MAA. The prepared hydrogels were highly pH responsive. This polymeric network could be a potential delivery system for colon targeting of 5-FU in colorectal cancers.
77 citations
TL;DR: Seven amphiphilic conetworks of methacrylic acid and a new hydrophobic monomer, 2-butyl-1-octyl-methacrylate (BOMA), were synthesized using group transfer polymerization and the nanophase behavior of the conetwork was probed using small-angle neutron scattering and atomic force microscopy.
Abstract: Seven amphiphilic conetworks of methacrylic acid (MAA) and a new hydrophobic monomer, 2-butyl-1-octyl-methacrylate (BOMA), were synthesized using group transfer polymerization. The MAA units were introduced via the polymerization of tetrahydropyranyl methacrylate (THPMA) followed by the removal of the protecting tetrahydropyranyl group by acid hydrolysis after network formation. Both THPMA and BOMA were in-house synthesized. Ethylene glycol dimethacrylate (EGDMA) was used as the cross-linker. Six of the conetworks were model conetworks, containing copolymer chains between cross-links of precise molecular weight and composition. The prepared conetwork series covered a wide range of compositions and architectures. In particular, the MAA content was varied from 67 to 94 mol %, and three different conetwork architectures were constructed: ABA triblock copolymer-based, statistical copolymer-based, and randomly cross-linked. The linear conetwork precursors were analyzed by gel permeation chromatography and 1H ...
77 citations
TL;DR: In this paper, the micellization of ionic amphiphilic diblock copolymers, polyisobutylene-block-poly(methacrylic acid) (PIB-b-PMAA), with a constant degree of polymerization of the non-ionic block and various degrees of polymerisation of the polyelectrolyte block, was examined in aqueous media by means of fluorescence spectroscopy using pyrene as a polarity probe.
77 citations
TL;DR: In this article, the swelling data in deionised water were extended by corresponding data measured in aqueous media of pH = 1 and pH = 12 starting at ca 15 °C phase diagrams of swelling ratio r (= mass hydrogel/mass xerogel) were determined at several temperatures (T) up to ca 70°C and reversibility in swelling/deswelling behaviour was verified on cooling back to 15 C in some instances a lower critical swelling temperature (T c ) was located, whereas in others there was merely a continuous decrease in r with T
Abstract: Hydrogels have been prepared by free radical polymerization in aqueous solution of N-isopropylacrylamide (NIPA) and of NIPA with acrylic acid (AA), methacrylic acid (MAA) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) For each copolymerization three comonomer feeds were used and for all systems three concentrations of a crosslinker were employed For all of the 30 polymers previously obtained, swelling data in deionised water were extended here by corresponding data measured in aqueous media of pH = 1 and pH = 12 Starting at ca 15 °C phase diagrams of swelling ratio r (= mass hydrogel/mass xerogel) were determined at several temperatures (T) up to ca 70°C and reversibility in swelling/deswelling behaviour was verified on cooling back to 15 C In some instances a lower critical swelling temperature (T c ) was located, whereas in others there was merely a continuous decrease in r with T Swellability at pH = 1 is lower than that in pure water, the reduction in r increasing with content of acidic comonomer At pH = 12 a similar reduction in r was observed in gels containing AA and AMPS, whereas with MAA as comonomer r is equal to or greater than the value in pure water The findings are discussed on the basis of the influence of pH on the ionisation of carboxyl groups, hydrogen bonding, and chelation
77 citations