Methacrylic acid monomer

Acrylic resins are generally well characterized by Py-GC/MS without the need for any derivatization reaction. However, in waterborne polymer dispersions it is common to have minor amounts of acrylic and/or methacrylic acid monomers added in the copolymerization to help the stability of the final latex. These monomers can also appear in the pyrolysis products, and it has been shown that with on-line derivatization they can be more efficiently revealed [85]. 

Bamford and Ward (1961) have obtained evidence which supports this conclusion, although the systems studied are somewhat different. They used an electric discharge to produce radicals in methacrylic acid (monomer) crystals and in various salts of this acid at 77°K. In some cases relatively narrow lines were obtained, and generally the characteristic nine-line spectrum was observed. Perhaps their most striking result was for the barium salt. At 77°K the four lines were weak and broad, whilst at room temperature a nine-line spectrum of intensity ratio very close to 1 2 4 6 6 6 4 2 1 resulted. These changes were reversed on cooling. 

An acrylic monomer is a low molecular weight functional acry-lated molecule which may be, for example, esters of acrylic acid and methacrylic acid. Monomers may be monofunctional or multifunctional (for example, di-, tri-, tetra-functional). 

SAL Salgado-Rodriguez, R., Licea-Claverie, A., and Amdt, K.F., Random copolymers of A-isopropylaciylamide and methacrylic acid monomers with hydrophobie spaeers pH-tnnable temperature sensitive materials, Eur. Polym. J., 40, 1931, 2004. 

Bis (4-methacryloylthiophenyl) sulfide Bis (4-vinylthiophenyl) sulfide monomer, hydrophilic polymer synthesis 2-Hydroxypropyl methacrylate monomer, inks 2-Hydroxyethylethylene urea monomer, large-volume polymers Methacrylic acid monomer, large-volume resins Methacrylic acid monomer, lube oil additives Butyl methacrylate monomer, lubricant additives Dicyclopentenyl methacrylate 2-Phenoxyethyl methacrylate 3,3,5-Trimethylcyclohexyl methacrylate... 

Diethylene glycol bis (allyl carbonate) monomer, organic synthesis Methacrylic acid monomer, organic synthetic Vinyl chloride monomer, paints Acrylamide Acrylonitrile 2-Hydroxyethylethylene urea Methyl methacrylate Styrene Vinyl chloride Vinyltoluene monomer monomer, paints/coatings 3,3,5-Trimethylcyclohexyl methacrylate monomer, photographic reproductive toners Dicyclopentenyl methacrylate 2-Phenoxyethyl methacrylate 3,3,5-Trimethylcyclohexyl methacrylate... 

In spite of this impressive list of characteristics the use of reactive acrylic adhesives has been limited to selected high-performance adhesive markets. Their growth otherwise, has been less rapid than expected (10). One of the principal reasons is due to the toxicity characteristics associated with methyl methacrylate and methacrylic acid monomers, major formulation constituents of "second-generation" acrylic adhesives, with regard to inhalation, ingestion and skin contact. Compositions containing large quantities of these monomers have been rejected on certain production lines such as automotive assembly. The low flash point and resultant flammability hazard have also been important contributors to the restricted use of modified acrylic adhesives (9 and 11). 

Alternative Synthesis of Acidic Poiymers. There are two approaches to homo- and copolymers of acrylic and methacrylic acids. In addition to the conventional use of acrylic acid and methacrylic acid monomers, the main theme of this article, there exists the possibility of converting polymers of the derivatives of these two monomers to acidic polymers. There would obviously have to be very extenuating circumstances to take this route industrially because of cost penalties. However, there are situations where there is a reason to do this. AvailabiUty of monomers is a good example. Acrylonitrile was at one time more available than acrylic acid in some parts of the world and simple hydrolysis of the polymer gave poly(acrylic acid). Other potential routes exist from such homo- and copolymers of acrylamide, acrylic and methacryUc esters, and acid chlorides. Although not further discussed here, the reader is reminded that polymer synthesis with acrylic monomers is very versatile and forethought is always necessary before plimging ahead. 

Block Synthesis. Water-soluble block copolymers are formed from the copolymerization of macromonomers of methacrylates with acrylic and methacrylic acid monomers and their solution properties compared with random copolymers of similar composition (224). Diblock and triblock copolymers may be prepared by a number of techniques and are also used on ink-jet inks (225) and scale inhibition in water boilers (226), respectively. Associative properties of block polymers to form micellar structures are well established (227,228). Triblock polyampholyte polymers are also known (229). 

Properties. Table l of methacrylic acid and derivatives (qv) lists many of the basic properties of methacrylic acid monomers. Tables 6 and 7 contain many of the additional physical and thermodynamic properties for commercially important monomers (29-32). 

The preparation of natural rubber-gra/t-methyl methacrylic acid has been reported by Lenka and coworkers. The vanadium ion was used as an initiator, which initiated the creation of free radicals on the backbone of natural rubber and this increased the interaction between the natural rubber and the methyl methacrylate surfaces. The coordination complexes derived from the acetylacetonate of Mn(III) ions could also be used as an initiator to form the natural rubber-gra/t-methyl methacrylic acid. Under different conditions, silver ions could be used as a catalyst to produce natural rubber-gra/t-methyl methacrylic acid with different concentrations of methyl methacrylic acid monomers, and potassium peroxydisulfate as an initiator. Consequently, these methods were successful in the preparation of compatible blended natural rubber and methyl methacrylic acid by graft copolymerization. This compatibility was confirmed by nuclear magnetic resonance and infrared spectroscopy techniques. The interaction between natural rubber and methyl methacrylic acid was significantly increased and was useful for further blending with other polyacrylate molecules or different polymer types. 

Rao and co-workers [62] applied Py-GC and C-NMR to the determination of sequence distribution of butadiene (B) - acrylonitrile (A) - methacrylic acid (M) terpolymers. Sequence distribution was described in terms of six triads (BBB, ABA, ABB, BBA, MBR and AMB) and found to vary with the mode of addition of methacrylic acid monomer. 

V. Thibert et al. developed an MIP for the extraction of cocaine and its metabolites, i.e. benzoylecgonine and ecgonine methyl ester from urine prior to LC-MS procedure. They used cocaine as the template during the polymerization of methacrylic acid monomers in combination with ethylene glycol dimethacrylate cross-linker. The polymerization reaction was performed in acetonitrile and azo-N,N/-bis-isobutyroni-trile was used as the initiator. The LOQs for cocaine, benzolecgonine, and methyl ester, after separation and preconcetration through the MIPs, were evaluated to be 0.09 ng/ mL, 0.4 ng/mL, and 1.1 ng/mL respectively [243]. 

In another work lacosamide based MIPs of methacrylic acid monomers were used for the solid-phase extraction of the template from rat plasma before LC analysis and the results revealed a recovery of over 98% for the SPE and the LOD and LR of the method were evaluated to be 0.03 pg mL and 0.1-100 pg mL [244]. B. B. Prasad et al. reported the MIP-based SPE of epinephrine and detection of the same through an MIP based sensing device in plasma cerebrospinal fluids. They reported the reaction of functionalized multiwalled carbon nanotubes (MWCNTs-COCl)] as a monomer with N-hydroxy phenylmaleimide and used glycoldimethylacrylate as the cross-linking agent. The LOD of the hyphenated method was reported to be 0.002 ng mL [245]. In another study M. Moein and co-workers developed MIP cartridges to be used in combination with HPLC for facile analysis of human insulin in plasma and urine. They used insulin as the template, in the reaction between meth-acrylicacid monomer and ethylene eglycol dimethacrylate cross-linker. The reaction initiation was achived by 2,2/-azobisisobutyronitrile. The overal results showed LODs of 0.2 ng mL in plasma and 0.03 ng mL in urine with recovery factors over 87% [246]. 

An ion selective MIP sensor for dopamine was introduced by M. Pesavento et al. [372]. This all-solid-state ion selective electrode was prepared through screen printing a graphite electrode which was modified with a multiwalled carbon nanotubes, with a dopamine selective MIP membrane based on methacrylic acid monomers and ethyl-eneglycole dimethacrylate cross-linker [372]. 

Morphin sensors based on MIPs have also been described [432,439,441]. Amperometric morphine sensors based on morphin imprinted poly(3,4-ethylene-dioxythiophene), which catalyze morphine oxidation and lowers the oxidization potential on an indium tin oxide (ITO) electrode, is an example. The same MIP has been used in the form of immobilized molecular particles for the same purpose. In one report, rather uniform MIP microspheres were prepared through precipitation polymerization to produce more active surface area. Poly(3,4-ethylenedioxythiophene) was utilized to immobilize the MIP particles, prepared through the reaction between methacrylic acid monomers and trimethylolpropane trimethacrylate crossHnkers in the presence of morphin, on indium tin oxide (ITO) glass [441]. Another microfluidic amperometric MIP-based morphin sensing system, using 3,4-ethylenedioxythiophene monomers, has also been reported in the literature [439]. 

Graft polymerization of methacrylic acid monomer could increase the hydro-philicity and impart negative charges on the membrane surface. It has been used to remove endocrine disrupting chemicals and pharmaceuticals active compounds [159]. In addition, surface grafting using redox initiation has been developed, which offers simplicity to the process. The reaction can be performed in an aqueous media at room temperature without an external activation [161]. However, redox initiation has relatively slow kinetics that requires a high concentration of monomer [164]. 

---