Methacrylic acid salts

Most attempts in the past to prepare higher molecular weight ultraviolet stabilizers have used the reaction of a preformed polymer with an ultraviolet-absorbing small molecule, e.g., of polymeric methacrylic acid salts with the 2-bromoethyl ether of the 1-hydroxyl group of 2,1-dihydroxybenzophenone (2). 

FIG. 6 Dependence of polyion fast diffusion coefficient Df on degree of neutralization a for poly(methacrylic acid) salt-free aqueous solutions. Mw = 30,000, polymer concentration c = 36.6 g/L. Polymer chains were ionized by neutralization with sodium hydroxide. (Adapted from Ref. 8.)... 

Ion-pair formation in the polymerization of methacrylic acid (salt form)... 

Poly(methacrylic acid) salts water Add// " 298 K 1980DAO... 

Copolymer system A simple example for the single ion conductor can be proposed by the copo1ymerization of oligo(oxyethylene) methacrylate and methacrylic acid salt [9-12]. The present copolymer is a typical single ion conductor without any added salt. Generally, the conductivity for single ion conductor is very low, in the range of 10 - 10 S/cm. This can be improved by this copolymerization. 

Saret acrylic and methacrylic acid salts (Sartomer) were compared withtriallyl cyanurate as co-curing agents in the peroxide vulcanisation of EPDM compounds for a number... 

Wea.kA.cid Cation Exchangers. The syathesis of weak acid catioa exchangers is a one-step process when acryHc acid or methacrylic acid is copolymetized with DVB. If an acryHc ester is used as the monomer iastead of an acryHc acid, the ester groups must be hydrolyzed after polymerization usiag either an acid or base (NaOH) to give the carboxyHc acid functionaHty, or the sodium salt (4) of it. 

Poly(acrylic acid) is insoluble in its monomer but soluble in water. It does not become thermoplastic when heated. The sodium and ammonium salts have been used as emulsion-thickening agents, in particular for rubber latex. The polymer of methacrylic acid (Figure 15.13 (VI)) is similar in properties. 

Cationic hydrophilic Glycol chitosan, DEAE-dextran, poly(ethyleneimine), poly(trimethylaminoethyl methacrylate) iodide salt 0.5 M acetic acid with 0.3 M NaiSO, or 0.8 M NaNO.,... 

In most ionomers, it is customary to fully convert to the metal salt form but, in some instances, particularly for ionomers based on a partially crystalline homopolymer, a partial degree of conversion may provide the best mechanical properties. For example, as shown in Fig. 4, a significant increase in modulus occurs with increasing percent conversion for both Na and Ca salts of a poly(-ethylene-co-methacrylic acid) ionomer and in both cases, at a partial conversion of 30-50%, a maximum value, some 5-6 times higher than that of the acid copolymer, is obtained and this is followed by a subsequent decrease in the property [12]. The tensile strength of these ionomers also increases significantly with increasing conversion but values tend to level off at about 60% conversion. 

Figure 4 Secant modulus versus percent conversion for Na and Ca salts of an ethylene/methacrylic acid ionomer.

The salt effect is very strong in polyconjugated polyelectrolytes. Figure 15 is a graph of the proton dissociation energy vs. the dissociation degree of PPA of different structures. Also, the graphs for poly(methacrylic acid) and a copolymer... 

The base materials include acrylic acid (ethylenecarboxylic acid, propenoic acid, vinylformic acid, CH2 CHCOOH) and its sodium salt, methacrylic acid [2-methylpropenoic acid, CH2 C(CH3)COOH], acrylamide (acrylic amide, propenamide, CH2 CH-CONH2), and methacrylamide. 

Polymers with a sizable number of ionic groups and a relatively nonpolar backbone are known as ionomers. The term was first used for copolymers of ethylene with carboxylated monomers (such as methacrylic acid) present as salts, and cross-linked thermoreversibly by divalent metal ions. Such polymers are useful as transparent packaging and coating materials. Their fluorinated forms have been made into very interesting ion-exchange membranes (considered further below). 

A salt of a polymer or copolymer of acrylic or methacrylic acid, in which the acid is neutralized with alkanolamines, alkylamines, or lithium salts [677], is suitable as a dispersing agent. 

V. L. Kuznetsov, G. A. Lyubitskaya, E. 1. Kolesnik, E. N. Kazakova, B. M. Kurochkin, and V. N. Lobanova. Plugging solution for isolating absorption zones in oil and gas wells—contains prescribed synthetic latex, water soluble salt of methacrylate-methacrylic acid copolymer as additive, and water. Patent RU 2024734-C, 1994. 

Figure 8. DMTA behavior for poly(styrene)-b-poly(isobutyl methacrylate-co-methacrylic acid) potassium salt.

Alternatively, esterification of carboxylic acid can be carried out in aqueous media by reacting carboxylic acid salts with alkyl halides through nucleophilic substitutions (Eq. 9.10).20 The reaction rate of alkyl halides with alkali metal salts of carboxylic acids to give esters increases with the increasing concentration of catalyst, halide, and solvent polarity and is reduced by water. Various thymyl ethers and esters can be synthesized by the reactions of thymol with alkyl halides and acid chlorides, respectively, in aqueous medium under microwave irradiation (Eq. 9.11).21 Such an esterification reaction of poly(methacrylic acid) can be performed readily with alkyl halides using DBU in aqueous solutions, although the rate of the reaction decreases with increasing water content.22... 

Ethylene ionomers consist of copolymers of ethylene and an organic add, such as methacrylic acid, the acid moieties of which have been neutralized to form a metal salt. The metal salts from neighboring chains tend to form clusters, such as the one shown schematically in Fig. 18.3. The net result is the overall structure shown in Fig. 18.2 g), in which the ionic clusters form weak crosslinks between adjacent chains. Ionomers also contain short and long chain branches, which are similar to those found in low density polyethylene. 

Ionomers are made in a two-stage process. In the first step, we copolymerize ethylene with small amounts of an organic acid containing a vinyl group, such as acrylic or methacrylic acid, in a high pressure reactor. In the second step, we neutralize the acid comonomers to form metal salts. We can create ionomers with a variety of metal salts, including sodium, calcium, and zinc. 

Ionomer. Ionomer is the generic name for polymers based on sodium or zinc salts of ethylene-methacrylic acid copolymers in which interchain ionic bonding, occurring randomly between the long-chain polymer molecules, produces solid-state properties. 

In a more simple and cheap way, silver clusters can be prepared in aqueous solutions of commercially available polyelectrolytes, such as poly(methacrylic acid) (PM A A) by photo activation using visible light [20] or UV light [29]. Ras et al. found that photoactivation with visible light results in fluorescent silver cluster solutions without any noticeable silver nanoparticle impurities, as seen in electron microscopy and from the absence of plasmon absorption bands near 400 nm (F = 5-6%). It was seen that using PMAA in its acidic form, different ratios Ag+ MAA (0.15 1-3 1) lead to different emission bands, as discussed in the next section (Fig. 12) [20]. When solutions of PMAA in its sodium form and silver salt were reduced with UV light (365 nm, 8 W), silver nanoclusters were obtained with emission band centered at 620 nm and [Pg.322]

Sodium ionomers are commercially recognized as the most effective nucleating agents for PET compounds. The typical use rate of sodium ionomer-based nucleating agents is 3-4 wt%. The sodium salt of poly(ethylene-co-methacrylic acid) is a particularly effective nucleating agent for PET. 

EMA ionomers (see Figure 4.30) are speciality thermoplastics copolymerized from ethylene and a small fraction of methacrylic acid, which is then transformed into the salt of sodium, zinc, lithium or another metal randomly distributed along the backbone. The backbone is identical to that of the polyolefins but the pendant groups are different, with a polar and ionic character. 

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