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.

Synthesis and Characterization of Double-Hydrophilic Model Networks Based on Cross-linked Star Polymers of Poly(ethylene glycol) Methacrylate and Methacrylic Acid

Abstract: A series of model networks based on cross-linked star polymers of poly(ethylene glycol) methacrylate (PEGMA) and tetrahydropyranyl methacrylate (THPMA), a protected form of methacrylic acid (MAA), were synthesized by group transfer polymerization (GTP), covering various compositions (homopolymers and copolymers), arm architectures (homopolymer, block and statistical copolymers), and star architectures (heteroarm and star block). The synthesis took place in tetrahydrofuran (THF) using tetrabutylammonium bibenzoate (TBABB) as the catalyst and 1-methoxy-1-(trimethylsiloxy)-2-methylpropene (MTS) as the initiator, and comprised a four- or six-step procedure: first, the formation of linear polymer chains upon the GTP of the monomer(s); next, the interconnection of the linear segments to star polymers (“arm-first” stars) by the in situ polymerization of the ethylene glycol dimethacrylate (EGDMA) cross-linker, followed by the addition of monomer(s) for a second time to grow new chains from the cores of the stars...

SEC Analysis of Poly(Acrylic Acid) and Poly(Methacrylic Acid)

Abstract: The accurate characterization of molar-mass distributions of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) by size-exclusion chromatography (SEC) is addressed. Two methods are employed: direct aqueous-phase SEC on P(M)AA and THF-based SEC after esterification of P(M)AA to the associated methyl esters, P(M)MA. P(M)AA calibration standards, P(M)AA samples prepared by pulsed-laser polymerization (PLP), and PAA samples prepared by reversible addition-fragmentation chain transfer (RAFT) are characterized in a joint initiative of seven laboratories, with satisfactory agreement achieved between the institutions. Both SEC methods provide reliable results for PMAA. In the case of PAA, close agreement between the two SEC methods is only observed for samples prepared by RAFT polymerization with weight-average molar mass between 80 000 and 145 000 g mol−1 and for standards with peak molar masses below 20 000 g mol−1. For standards with higher molar masses and for PLP-prepared PAA, the values from THF-based SEC are as much as 40% below the molar masses determined by aqueous-phase SEC. This discrepancy may be due to branching or degradation of branched PAA during methylation. While both SEC methods can be recommended for PMAA, aqueous-phase SEC should be used for molar-mass analysis of PAA unless the sample is not branched.

Electrophotographic sensitive body

Abstract: PURPOSE:To obtain high-grade images in spite of long-term use by forming the film of a silicone graft copolymer having a specific acid value on the surface of a photosensitive layer. CONSTITUTION:The film consisting of the graft copolymer which is obtd. by copolymerizing a macromonomer having a (meth)acryloyl group at one terminal of silicone, alpha,beta-ethylenic unsatd. carboxylic acid and other radical polymerizable monomer and has 30 to 260mgKOH/g resin acid value is formed in the upper part of the photosensitive layer. This silicone macromonomer is a high mol.wt. monomer consisting of the silicone as its skeleton and the preferable number average mol.wt. is 1,000 to 50,000 in terms of polyethylene and the amt. of the monomer to be used is 0.5 to 60wt.% of the total weight of the whole monomer. Acrylic acid or methacrylic acid is preferable as the alpha,beta-ethylenic unsatd carboxilicacid and the amt. of the acid to be used is usually about 3 to 40wt.% at which the acid value of the graft copolymer attains 30 to 260mgKOH/g resin.

Photomechanical degrafting of azo-functionalized poly(methacrylic acid) (PMAA) brushes.

Abstract: We report on the preparation and characterization of photosensitive polymer brushes. The brushes are synthesized through polymer analogous attachment of azo-benzene groups to surface-attached poly(methacrylic acid) (PMAA) chains. The topography of the photosensitive brushes shows a strong reaction upon irradiation with UV light. While homogeneous illumination leaves the polymer topography unchanged, irradiation of the samples with interference patterns with periodically varying light intensity leads to the formation of surface relief gratings (SRG). The height of the stripes of the grating can be controlled by adjusting the irradiation time. The SRG pattern can be erased through solvent treatment when the periodicity of the stripe pattern is less than the length of the fully stretched polymer chains. In the opposite case, photomechanical scission of receding polymer chains is observed during SRG formation, and the inscribed patterns are permanent.