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.

Molecular interactions in poly(methacrylic acid)/poly(N-isopropyl acrylamide) interpenetrating polymer networks

Abstract: The molecular interactions between the component networks in poly(methacrylic acid)/poly(N-isopropyl acrylamide) (PMAA/PNIPAAm) interpenetrating polymer networks (IPNs) were investigated using attenuated total reflectance (ATR)-Fourier transform IR (FTIR) spectroscopy. Hydrogen-bond formation was noted between the carboxyl groups of PMAA and the amide groups of PNIPAAm. The ATR-FTIR results showed shifts in the carboxylic and amide groups, indicating the existence of hydrogen bonding between these two individual networks within the IPNs. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1077–1082, 2001

Atmospheric aqueous phase radical chemistry of the isoprene oxidation products methacrolein, methyl vinyl ketone, methacrylic acid and acrylic acid--kinetics and product studies.

Abstract: Kinetic and mechanistic studies were conducted on the isoprene oxidation products methacrolein, methyl vinyl ketone, methacrylic and acrylic acid reacting with hydroxyl and nitrate radicals and sulfate radical anions in aqueous solution by use of the laser flash photolysis technique and a reversed-rate method for kinetics. High-performance liquid chromatography/mass spectrometry was applied for product analysis. The kinetic investigations show the highest reactivity of the hydroxyl radical followed by sulfate and nitrate radicals. For methacrolein and methyl vinyl ketone the following rate constants have been determined at 298 K: k(OH+methacrolein) = (9.4 ± 0.7) × 109 M−1 s−1, k(OH+methylvinylketone) = (7.3 ± 0.5) × 109 M−1 s−1, k(NO3+methacrolein) = (4.0 ± 1.0) × 107 M−1 s−1, k(NO3+methylvinylketone) = (9.7 ± 3.4) × 106 M−1 s−1, k(SO4−+methacrolein) = (9.9 ± 4.9) × 107 M−1 s−1 and k(SO4−+methylvinylketone) = (1.0 ± 0.2) × 108 M−1 s−1. Temperature and pH dependencies of the reactions of OH, NO3 and SO4− with methacrolein, methyl vinyl ketone, methacrylic and acrylic acid as well as Arrhenius parameters have been obtained and discussed. Product studies were performed on the OH radical induced oxidation of methacrolein and methyl vinyl ketone. In the reaction of methacrolein + OH methylglyoxal and hydroxyacetone were identified as first oxidation products with yields of 0.099 and 0.162. Methylglyoxal was primarily produced in the oxidation of methyl vinyl ketone with a yield of 0.052. For both precursor compounds the formation of glycolaldehyde was observed for the first time with yields of 0.051 and 0.111 in the oxidation of methacrolein and methyl vinyl ketone, respectively. Furthermore, highly functionalised C4 compounds were determined from the oxidation of both precursor compounds, but for the first time for methyl vinyl ketone. Reaction schemes were developed based on known peroxyl radical reaction mechanisms. The aqueous phase conversion of the first generation isoprene oxidation products can potentially contribute to tropospheric aqueous phase budgets of important carbonyl and dicarbonyl components which are expected to be conducive to the formation of aqSOA.

Synthesis of Biodegradable Gum ghatti Based Poly(methacrylic acid-aniline) Conducting IPN Hydrogel for Controlled Release of Amoxicillin Trihydrate

Abstract: Gum ghatti-graft-poly(methacrylic acid-aniline) interpenetrating network (IPN) hydrogel was prepared by a two-step aqueous polymerization method. First, poly(methacrylic acid) (poly(MAA)) chains were graft co-polymerized onto a Gum ghatti (Gg) backbone via free radical polymerization. Different reaction conditions were optimized in order to incorporate maximum water uptake capacity of the synthesized hydrogel. The synthesized hydrogel network showed a pH-dependent swelling behavior. Second, aniline (ANI) monomer was penetrated through the preformed Gg-g-poly(MAA) network by simple oxidative polymerization method. The homogeneity and distribution of different ions of the cross-linked hydrogels were investigated by the time-of-flight–secondary-ion mass spectrometry chemical imaging technique, and a correlation analysis by color overlay and scatter plot technique. The resulting cross-linked hydrogels’ structure, morphology, and thermal behavior were investigated. Biodegradation studies of the cross-linked hy...