Cross with acrylic acid

Choi and co-workers [579] studied the reactivity of vinyl-terminated self-assembled monolayers (SAMs) of undec-lO-ene-1-thiol on gold (see Fig. 6.32) toward olefin cross-metathesis (CM). Vinyl groups on SAMs were successfully converted into a, P-unsaturated carbonyl groups by CM with acrylic acid, methyl acrylate, and acrylamide. Result shows that various useful functional groups can be introduced to SAMs on gold (and other solid surfaces) by olefin CM and suggests an alternative to the S3mthesis of desired molecules in solution [579]. 

Cossy et al. demonstrated that, in the presence of the ruthenium catalyst 10 and Pt02, the tandem cross-metathesis—hydrogenation—cyclization reactions of the alkenol 19 with acrylic acid 20 or acrolein 21 under H2 atmosphere gave the lactone 22 or lactol 23, respectively (Scheme 8).89 The ruthenium catalyst 10 and Pt02 are compatible under the reaction conditions. 

Because the free radical initiated graft reaction can also lead to the cross-linking of polyethylene, copolymers of ethylene and with acrylic acid (184,185), glycidyl methacrylate (184,186), methacrylic acid and 10-undecenoic acid (187-189) were synthesized to compatibilize polyethylene/polyamide blends. The poly (ethylene-co-methacrylic acid) ionomers neutralized by sodium (184) and zinc (45,118,190-192) has also used as compatibilizers. High energy irradiation, used to modify the surface of fibers or films at beginning, was also used to compatibilize the polyethylene/polyamide blends (193-196). 

Plasma treatment of microchannels can be useful for improving the functionality of microdevices. For example, previous studies have shown that PDMS microchannels can be made hydrophilic by the addition of silane molecules with polar head groups [6]. In this process (3-mercaptopropyl)trimethoxysilane (3-MPS) was absorbed to PDMS to increase the hydrophilic properties of microchannels. Additionally, plasma polymerization has been used to induce in the long-term hydrophilic surface modification by covalently bonding a polymer layer to the surface. Barbier et al. [7] describe a method based on plasma polymerization modification with acrylic acid coatings. First, argon plasma pretreatment was used to activate trace oxygen molecules in the chamber, which partially oxidize the top layer of the substrate. This step cross-linked the surface to reduce ablation of silicon... 

Copolymers of methyl-, ethyl- or -BA with acrylic acid were synthesized and used to fabricate ionically cross-linked, via aluminum acetylacetonate, membranes for the separation of toluene-t-octane mixtures by PV at high temperatures. At 100°C for a feed containing 50 wt% toluene, the normalized flux of the permeate increased from 20 to over 1000 kg pm/m h in going from the methyl to -BA, while the toluene over /-octane selectivity decreased from 13 to about 2.5. 

Vinyl ester resins The vinyl ester resins are essentially epoxide resins, normally the digly-cidyl ether of bisphenol A, that have been reacted with acrylic acid or its derivatives. The unsaturation in the acid residues provides sites for a cross-linking mechanism based on free radical polymerization. The retention of the bisphenol A backbone in the chain of the cross-linked polymer conserves most of the mechanical and physical properties associated with the parent epoxy. The resins thus provide a combination of ease of processing with good chemical resistance and mechanical behaviour. 

The prostheses consist of networks of fibrils of diameter approximately Ip, separated by pores of about lOp. Considerable melding occurs at the crossing points. Such structures have an enormous surface area, so that the results in Table 1 indicate a greater sensitivity to liquids than is found with other solid specimens (such as films) under similar conditions. It is apparent that hydrophilic vinyl monomers are strong swelling agents for Biomer and partially dissolve the polymer. This is particularly pronounced with acrylic acid which may ultimately be able to completely dissolve a prosthesis. 

Influence of Comonomers on Microgel Properties. The overall physicochemical properties of a microgel depend not only on the cross-linker concentration, but also on the concentration of monomer/comonomers used in the synthesis. The addition of a small amount of comonomer (typically 1-5 wt% monomer) can have a dramatic effect on the overall properties of the resultant microgel particles. For example, a pH- and temperature-sensitive microgel can be prepared by copolymerizing poly(NIPAM) with acrylic acid. These spherical particles undergo... 

MIP catalysts. Efendiev etal. have performed seminal research in which the oxidation of ethylbenzene to acetophenone was studied (Scheme I4).36a,37 Having copolymerized the diethyl ester of vinylphosphonic acid with acrylic acid, the resulting polymer was then functionalized with Co(II) complexes, while the template was added. A series of polymers were prepared in which the template was the substrate, an analog of the intermediate, or the product itself. Cross-linking of the prearranged polymer was effected using /V,/V-methylenebis(acrylamide), and a control polymer was prepared which did not contain imprinted sites. The substrate-imprinted polymer displayed a catalytic... 

Other means to introduce polymerizable groups on the fatty acids is the acrylation of the epoxide rings (Fig. 22.21) [4,103], hi this sense, the reaction of epoxidized fatty acids with acrylic acid incorporates acrylate groups on the fatty acid structure. Next, the monomers produced can be copolymerized with styrene using a free radical initiator to produce cross-linked materials. 

After neutralization by a metal cation, copolymers with acrylic acid give materials that behave like thermolabile cross-linked systems. 

Poly(acrylic acid) and Poly(methacrylic acid). Poly(acryHc acid) (8) (PAA) may be prepared by polymerization of the monomer with conventional free-radical initiators using the monomer either undiluted (36) (with cross-linker for superadsorber appHcations) or in aqueous solution. Photochemical polymerization (sensitized by benzoin) of methyl acrylate in ethanol solution at —78° C provides a syndiotactic form (37) that can be hydrolyzed to syndiotactic PAA. From academic studies, alkaline hydrolysis of the methyl ester requires a lower time than acid hydrolysis of the polymeric ester, and can lead to oxidative degradation of the polymer (38). Po1y(meth acrylic acid) (PMAA) (9) is prepared only by the direct polymerization of the acid monomer it is not readily obtained by the hydrolysis of methyl methacrylate. 

Solubilization of vinylpyrrolidone, acrylic acid, and A,A -methylene-bis-acrylamide in AOT-reversed micelles allowed the synthesis in situ of a cross-linked polymer with narrow size distribution confined in the micellar domain. These particles displayed high entrapment efficiency of small hydrophilic drugs and have been considered interesting drug delivery systems [239],... 

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