Polymethacrylic acid

The soapless seeded emulsion copolymerization method was used for producing uniform microspheres prepared by the copolymerization of styrene with polar, functional monomers [115-117]. In this series, polysty-rene-polymethacrylic acid (PS/PMAAc), poly sty rene-polymethylmethacrylate-polymethacrylic acid (PS/ PMMA/PMAAc), polystyrene-polyhydroxyethylmeth-acrylate (PS/PHEMA), and polystyrene-polyacrylic acid (PS/PAAc) uniform copolymer microspheres were synthesized by applying a multistage soapless emulsion polymerization process. The composition and the average size of the uniform copolymer latices prepared by multistage soapless emulsion copolymerization are given in Table 11. 

Poly(3,3 ionene) 80 Polylysine 148 Polymethacrylic acid 54 Polypeptides 147 Polypropylene oxide 158 Polysoaps 63... 

A wide range of polyacrylic acids (PAAs), polymethacrylic acids (PMAAs), polyacrylamides (PAMs), their salts and homo-, co-, and terpolymer derivatives are available from a great many manufacturers around the world today. Polyacrylates especially are a backbone of BW chemical formulations and are manufactured with an almost infinite variety of average molecular weights (MWs), MW distributions, activity strengths, and other characteristics. 

By coelectrolysis of polymethacrylic acid with e-acetaminocaproic acid or cyano-acetic acid the alkylacetamido- or cyanomethyl group can be grafted on to the main chain of the polymer [205]. 

Gregor, H. P. Frederick, M. (1957). Titration studies of polyacrylic acid and polymethacrylic acids with alkali metals and quaternary ammonium bases. Journal of Polymer Science, 23, 451-65. 

We have cited the case of epoxidation with peracids earlier in this book. A cross-linked polymethacrylic acid can, in principle, be treated with a sulphonic acid catalyst and H2O2 to give the peracid, which will allow epoxidation to be carried out in a convenient way, while the polymer can be reused. The key advantage is that the product stream does not contain an acid, which may be harmful in several ways. 

Hydration of polymeric membranes may be influenced by the chemical identity of the polymers. A hydrophilic polymer has a higher potential to hydrate than a hydrophobic one. Sefton and Nishimura [56] studied the diffusive permeability of insulin in polyhydroxyethyl methacrylate (37.1% water), polyhydroxy-ethyl acrylate (51.8% water), polymethacrylic acid (67.5% water), and cupro-phane PT-150 membranes. They found that insulin diffusivity through polyacrylate membrane was directly related to the weight fraction of water in the membrane system under investigation (Fig. 17). 

However, the findings of Prins and his coworkers were strongly criticised by Horse-field and Wasserman 147,148) who obtained esr spectra at 77 K for a number of Fe(Cp)2+ species, as powders, crystals, and glasses. All the systems gaveg = 3.15—3.35 andg = 1.82—1.90, and it was concluded that the Fe(Cp)2+ complexes were unstable under the conditions used by Prins et al. 72, 144) and that the observed signals were due to free Fe3+. Similar results were also obtained by Rowe and McCaffery 149) who studied Fe(Cp)2+ BF4 by MCD at 9 K and 290 K and by esr at 20 K in polymethacrylic acid. 

Polymethacrylic Acid Medium Induced Medium Flexible Linear Side Chain Moderate... 

Thus, polymethacrylic acid undergoes net scission on gamma radiolysis with a G-value of approximately 4, while polyacrylic acid, on the other hand, undergoes net crosslinking with a G-value of approximately 1.2 (7). Crosslinking in polyacrylic acid is favourable because of the formation of main chain radicals. These can react to form crosslinks between polymer chains. 

Mention should be made of an expedient for evaluating correct molecular weights without resort to equilibrium dialysis or using (dn/dc2)x>M. It has been used by Vrij and Overbeeck146) for half neutralised polymethacrylic acid in 0.1 molar solutions of sodium halides. The relevant equation is... 

Fig. 47. Square root of apparent molecular weight by LS as a function of molar refractive index increment of salt for sodium polymethacrylic acid in aqueous solution of different sodium halides146 ...

The humates present in soil are polyelectrolytes and bear some similarity to polyacrylic acid and polymethacrylic acid (49, 50). The molecular weight distribution for the humates is considerable fulvic acid fractions of 1,000 daltons have been isolated (51) while humic acid molecular weights obtained by gel chromatography are in the range 17,000 to 100,000 daltons according to the type of soil from which it was extracted (52). However, ultracentrifugation analysis indicates a molecular range of 2,000 to 1,500,000 daltons for humic acids (55). 

Nakamura et al. [54] deseribe a mieropartieulate dosage form of budesonide, consisting of novel bioadhesive and pH-dependent graft copolymers of polymethacrylic acid and polyethylene glycol, resulting in elevated and constant plasma levels of budesonide for 8 hr after nasal administration in rabbits. 

Complex formation of Hg +, Zn +, and Pb + with polyacrylic and polymethacrylic acids has been studied [63] voltammet-rically, using mercury drop and glassy carbon rotating disk electrodes. The formation constants of these complexes were calculated. 

A similar method of hydrolysis was described for poly( vinyl alcohol) used as a template. In this case, T was -CH2-CH- and, after hydrolysis, poly(vinyl alcohol) and polyacrylic or polymethacrylic acid were obtained. The hydrolyzed product gives the color reaction with I2 in the presence of H3BO3 - specific to poly(vinyl alcohol). The second product of hydrolysis, after esterification by diazomethane, was identified as polyfmethyl methacrylate) by NMR and IR spectrometry. Hydrolysis was also applied in the case of ladder-type polymers obtained by polymerization of mutliallyl monomers. The polymerization should result in polymer consisting, at least partly, ladder-type blocks ... 

After hydrolysis by 2N methanol solution of H2SO4, the product was neutralized with KOH to pH=5 and methanol evaporated. The dry residue was expected to be poly(allilamine), polymethacrylic acid, and K2SO4. Indeed, after extraction with anhydrous methanol and acetone, poly(allilamine) was identified by NMR and IR spectrometries. After evaporation, solvent from the methanol part of the extract insoluble in chloroform part was obtained. After esterification by diazomethane the product was identified as polyfmethyl methacrylate) on the basis of IR and H-NMR spectroscopy. IR spectroscopy was applied in order to examine the copolymerization of multimethacrylate (p-cresyl-formaldehyde oligomers with methacrylic groups) with st3rrene. It was found that double bond peak at 1650 cm disappeared during the process and it was absent in the product of polymerization. Polymerization and... 

Open-cell PolyHIPE materials have also been prepared from hydrophilic methacrylates which, on hydrolysis, yield hydrophilic polymethacrylic acid-based species [155]. Stable HIPEs containing high levels of glycidyl methacrylate can also be formed, from which porous polymers can be made. These have considerable potential for further exploitation due to the reactive epoxide group [156],... 

There is some reason to expect that conversion of the anhydride to a half-ester might reduce the sensitivity of the copolymers. Hiraoka (10) determined the relative sensitivities of PMMA, PMA (polymethacrylic acid) and PMA AN (polymethacrylic anhydride) by measuring the gaseous products (CO, C02, and H2) given off when these polymers were exposed to electron beam radiation of 2.5 keV at 297 °K. He found that the G values (number of chemical events produced per 100 eV of absorbed radiation) for the removal of side groups are 2.0, 7.4 and 16 for PMMA, PMA and PMA AN, respectively. Anderson (11) found a similar relative order of sensitivity. For copolymers of methylmethacryate with 25% dimethylitaconate, 25% monomethyl itaconate or 25% itaconic acid (or anhydride) the G(s) values were 1, 2, 3, respectively. For the copolymer of alpha-methylstyrene and monomethyl maleate, on the other hand, we find an increase in sensitivity by a factor of 2.5 over the corresponding anhydride as described below. 

Wohrle et al. [66] reported the synthesis of covalently bound phthalocyanine moieties to chloromethylated polystyrene polymethacrylic acid poly(N-vinylpyrrolidone-co-methacrylic acid) [67]. 

Figure 1. Brittle point of n-alkyl esters of polyacrylic and polymethacrylic acid (27)...

Synthetic water treatment polymers were first introduced in the 1950s. The first important synthetic polymers included hydrolyzed polyacrylamide and various high molecular weight (100,000+) homopolymers of polyacrylic acid and polymethacrylic acid, together with their sodium salts. 

The structures of polyacrylic acid (PAA) and polymethacrylic acid (PMAA) are shown in Figure 5.2. 

Polymethacrylic acid Aromatic hydrocarbons, esters, Ether, alcohols, aliphatic... 

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