A facile synthesis route for carboxyaryl-methacrylates: a way to obtain aromatic polyelectrolytes

Abstract

This paper describes a exible synthetic route for the preparation of the following methacrylic acid derivative monomers with aromatic spacers, including salicylic acid derivatives, in high yields: 2-methacryloyloxybenzoi c acid (2-MBA), methyl-2-methacryloyloxybenzoate (M2-MB), 3-methacryloyloxybenzoic acid (3-MBA), methyl-3-methacryloyloxybenzoate (M3-MB), 4-methacryloyloxybenzoic acid (4-MBA), methyl-4-methacryloyloxybenzoate (M4-MB), 4-methacryloyloxy phenyl acetic acid (4-MPAA), methyl-4-methacryloyloxyphenylacetate (M4-MPA) and methyl-4-methacryloyloxyphenylpropionate (M4-MPP). The preparation of the respective aromatic polymers from these monomers by solution free-radical polymerization and their characterization are also described. The position of the substituent in the aromatic spacer ring plays a very important role in the properties of the polymers prepared. While for methyl-ester substitution the glass transition temperature increases from ortho to para isomers, in the case of carboxylic acid substitution this value decreases from ortho to para isomers. The four polymers prepared with free acid groups are hydrophobic polyelectrolytes, as shown by their behavior in aqueous NaCl solutions at different pH values, making them potential candidates for new pH sensitive materials.

Effect of method of preparation on properties of temperature and pH-sensitive gels: Chemical crosslinking versus irradiation with e-beam

“…The characterization of those monomers using FT-IR and 1 H NMR techniques showed absorption bands and chemical shifts that agree with the previously reported by our group [18].…”

“…2-methacryloyloxybenzoic acid (ORTHO), 3-methacryloyloxybenzoic acid (META) and 4-methacryloyloxybenzoic acid (PARA) were synthesized as previously reported by Licea-Claveríe et al [18].…”

Well‐defined N‐Isopropylacrylamide Dual‐Sensitive Copolymers with LCST ≈38 °C in Different Architectures: Linear, Block and Star Polymers

“…An acid comonomer with a p K a value higher than that of acrylic acid (AA) or methacrylic acid (MA) was needed given the fact that the LCST of copolymers of NIPAAm with AA or MA are to high at pH 7-8. [ 21 ] We have chosen three acid comonomers with p K a values between 5 and 6, namely, 5MPA with p K a = 6.14, [ 57 ] 4MBA with p K a = 5.3 [ 56 ] and 2MBA with p K a = 5.8. [ 56 ] Furthermore, all three acid comonomers contain hydrophobic moieties as spacer groups (see Figure 1 ).…”

“…[ 21 ] We have chosen three acid comonomers with p K a values between 5 and 6, namely, 5MPA with p K a = 6.14, [ 57 ] 4MBA with p K a = 5.3 [ 56 ] and 2MBA with p K a = 5.8. [ 56 ] Furthermore, all three acid comonomers contain hydrophobic moieties as spacer groups (see Figure 1 ). This results in the fact that they are water insoluble at pH values lower than 5.…”

The Use of the RAFT‐Technique for the Preparation of Temperature/pH Sensitive Polymers in Different Architectures

“…The macro-CTA (1 g) was dissolved in 40 mL of ethanol (for poly-DEAEM) or 1.5 g of macro-CTA in 30 mL of 1,4-dioxane (for polyNIPAAm) before adding the initiator and the second monomer in different amounts aiming different compositions. The monomers used to grow the second block were 2-methacryloyloxy benzoic acid (MAOB), prepared according to a published procedure, [7] and HA, respectively. In the case of polymeric stars, the second monomer was a crosslinker: ethylenglycol-dimethacrylate (EGDMA) or divinylbenzene (DVB) in the case of stars with polyNIPAAm arms, while mixtures of EGDMA with NIPAAm monomer were used for the preparation of stars with polyHEMA arms in different ratios.…”