Methacrylate macromonomers

The most used transfer agents in this class are the methacrylate macromonomers (e.g. 66-68) and AMS dimer (76). The applications of these compounds are summarized in a review.110... 

Transfer constants of the methacrylate macromonomers in MMA polymerization do not depend on the ester group but are slightly higher for MAA trimer. Compounds 72 and 73 are derived from the MMA trimer (67) by selective hydrolysis or hydrolysis and reesterification respectively. They offer a route to telechelic polymers. 

Polymerizations of methacrylic monomers in the presence of methacrylic macromonomers under monomer-starved conditions display many of the characteristics of living polymerization (Scheme 9.36). These systems involve RAFT (Section 9.5.2). However, RAFT with appropriate thiocarbonylthio compounds is the most well known process of this class (Section 9.5.3). It is also the most versatile having been shown to be compatible with most monomer types and a very wide range of reaction conditions.382... 

Poly (alkyl methacrylate) macromonomers are formed by reaction of the living polymer with VBC. This method was shown to be free of side reactions and quantitative, in spite of the low nucleophilicity of the carbanionic site involved 72,75). 

Following quantitative methylation of the co-fert-chloro site by trimethyl aluminum, the methylated polyisobutylene methacrylate macromonomer was co-polymerized with MMA by Group Transfer Polymerization [87]. PMMA-g-PIB graft copolymers with controlled MW and composition were obtained. The structure and physical properties were determined by the [MMA]/[MA-PIB] and [MMA]/[Initiator] ratios. 

Sharkey20 found that living poly(methyl methacrylate) reacts efficiently and without side reaction with p-vinylbenzyl iodide (or bromide) at low temperature yielding poly(methyl methacrylate) macromonomers bearing at the chain end a styryl group (poly(methyl methacrylate)macromonomer). 

Waite 93,100) investigated the copolymerization of lauryl methacrylate macromonomers with methyl methacrylate and used the graft copolymers as stabilizers for the dispersions. The polar backbone is more compatible with dispersed polar droplets and the grafts, which are much less polar, are miscible with the continous phase, thus yielding stable oil-in-oil -dispersions. 

To overcome the difficulties of ESI-MS, Simonsick and Prokai added sodium cations to the mobile phase to facilitate ionization [165,166]. To simplify the resulting ESI spectra, the number of components entering the ion source was reduced. Combining SEC with electrospray detection, the elution curves of polyethylene oxides) were calibrated. The chemical composition distribution of acrylic macromonomers was profiled across the molar mass distribution. The analysis of poly(ethylene oxides) by SEC-ESI-MS with respect to chemical composition and oligomer distribution was discussed by Simonsick [167]. In a similar approach aliphatic polyesters [168], phenolic resins [169], methyl methacrylate macromonomers [169] and polysulfides have been analyzed [170]. The detectable mass range for different species, however, was well below 5000 g/mol, indicating that the technique is not really suited for polymer analysis. 

Acrylic Macromonomers. Acrylic-methacrylic macromonomers prepared by catalytic chain transfer using cobalt(II) chelates afford polymer chains, each with an olefinic endgroup (18, 24). Such macromonomers can be polymerized or copolymerized to produce graft polymers that are useful in coatings, fibers, films, and composite materials applications (24). Moreover, one is able to synthesize macromonomers containing several alkylmethacrylates, alkylacrylates, and styrene (IS). 

CCT of benzyl methacrylate leads to a mixture of poly(benzyl methacrylate) macromonomers from which the dimer macromonomer could be isolated.516 When the benzyl dimer is used as a RAFT chain-transfer agent, PMMA with a- and co-terminal benzyl methacrylate units is obtained. Catalytic hydrogenation of the a,co-benzyl terminal methyl methacrylate polymer results in the evolution of toluene and formation of a,co-dicarboxyl functional telechelic PMMA. 

Branched acrylic polymers based upon the copolymerization of acrylates and related monomers with methacrylate macromonomers are particularly useful in waterborne coatings. A macromonomer based upon isobutyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxyethyl methacrylate was copolymerized with butyl acrylate, 2-hydroxyethyl acrylate, meth-acrylic acid, methyl methacrylate, and styrene.518 After neutralization with dimethylethanolamine or inorganic bases, the polymer could be cross-linked with melamine resin on a metal surface. These systems may be used for either pigmented layers or clear coats. 

Copolymerization of di- and trimethacrylates with functionalized monomers, like glycidyl methacrylate, leads to low-viscosity oligomers capable of nonradical cross-linking. This process promises substantial value for industrial applications. Star polymers useful in coatings were prepared by copolymerizing methacrylate macromonomers with diacrylates.519 For instance, a star polymer was synthesized by copolymerization of a 2-ethylhexyl methacrylate/isobutyl methacrylate/hydroxyethyl methacrylate macromonomer with butanediol diacrylate. 

Fig. 44. Right copolymers of pDMS methacrylate macromonomers with different branch distributions prepared by different methods RAFT (top, solid line), FRP (middle, dotted line), ATRP (bottom, broken line). Left impact of branch distribution on mechanical properties (stress vs draw ratio) [320]...

In a similar way, n-butyl acrylate was copolymerized by ATRP with methacrylate macromonomers containing highly branched polyethylene prepared by Pd-catalyzed living ethylene polymerization. The observed reactivity ratios depend on the molecular weight and concentration of the macromonomer. The resulting graft copolymers showed microphase separation by AFM [304]. 

TMI. Boyer et al. [255] directly used this monomer for the synthesis of N,J r -dimelhylethylamino methacrylate macromonomer (Scheme 53). 

Various macromonomers made from an addition-fragmentation process have been employed as precursors of graft copolymers [292,297-300]. But Krstina et al. [301] also characterized the use of such macromonomers in the synthesis of block copolymers. They explained that for macromonomers based on methacrylic monomers (Scheme 60,1), fragmentation of the adduct (Scheme 60, 2) (formed by addition of the methacrylate monomer onto the methacrylate macromonomer) always dominates over reaction with the monomer. This fragmentation leads to block copolymers and graft copolymerization does not occur. 

Similar methods have been employed for the preparation of polyvinylpyrrolidone, polystyrene, or polyacetoxyethyl methacrylate macromonomers. 

Ohtani, H., Luo, Y. E, Nakashima, Y., Tsukahara, Y, and Tsuge, S., Determination of End Group Functionality in Polyjmethyl methacrylate) Macromonomers by Ppn-olysis Simultaneous Multidetection Gas Chromatography, Anal Chem., 69, 1438,1994. 

Keywords copper mediated living radical polymerization, H NMR spectroscopy, poly(ethylene glycol), methacrylates, macromonomer, macroinitiator, solvent effect. 

The exo-olefin is a precursor to a variety of chain-end-functionalized polymers via postpolymerization reaaions as shown in Scheme 37. Hydroxy-functionalized PIB has been utilized as a precursor for the preparation of RAFT macromo-lecular CTAs and carboxylic acid end-fimctionalized polymers. Telechelic PIB diols have been prepared using p-dicumyl chloride/BCU initiator system followed by dehydro-chlorination, hydroboration, and alkaline peroxide oxidation. Aldehyde end-fiinctionalized PIBs have been used to prepare carboxyl- and hydroxyl-terminated poly-mers. Carboxylic acid-functionalized PIBs have also been prepared from the oxidation of the methyl ketone-functionalized PIBs." The hydroxyl-functionalized PIBs have also been used to prepare methacrylate macromonomers by their reaction with methacryloyl chloride in the presence of triethylamine. The homopolymerization and copolymerization of these maaomonomers with methyl methacrylate were also reported. Cyanoacrylate-funaionalized PIBs prepared via the hydroxyl-functionalized PIB were also reported by Kennedy et al. ... 

Only a limited number of examples of copolymers with grafted polyoxazolines are desaibed in the literature. The copolymerization of oligo(2-methyl-2-oxazoline) acrylate and methacrylate macromonomers with styrene or MMA was described by Shoda as well as the copolymerization of oligo(2-phenyl-2-oxazoline) acrylate maaomonomers with MMA. °° Weber et succeeded in the synthesis of... 

The dispersion polymerisation of styrene was studied in a mixed ethanol-water medium using 0.1-2 wt% of omega-methoxy poly(ethylene oxide)40 undecyl-alpha-methacrylate macromonomer as a steric stabiliser. The polymerisation rate reached a maximum at a styrene conversion of around 18% and remained almost constant up to about 55% conversion. The molecular weight of the polymer increased with increasing conversion of styrene up to about 55%. The polymerisation rate and activation energies were studied and discussed. Spherical monodisperse particles of around 250 nm diameter were obtained for the final stable latices.The grafted poly(ethylene oxide) macromonomers were enriched and anchored on the surface of PS latex particles with a top surface composition of 28% macromonomer. 33 refs. SINGAPORE Accession no.665916... 

Poly(dimethylaminoethyl methacrylate) macromonomers were prepared by ATRP using allyl 2-bromoisobutyrate (ABIB, (16))/CuBr/tris[2-di(butyl acrylate) aminoethyl] amine, (BA6-TREN) or allyltrichloroacetamide/CuBr/BA6-TREN as the initiation systems (94) (eq. 24). 

Suggest a route, via combination of ATRPand CuAAC reaction, foref cient synthesis of polystyrene-fc-poly(w-butyl acrylate)-methacrylate macromonomer, where each block in the copolymer chain has... 

PEC methacrylic macromonomer PLA methacrylic macromonomer POE methacrylic macromonomer... 

Vegetable oil derived macromonomers were successfully synthesized from castor, lesquerella, and vemonia oils. CAM was effectively incorporated in vinyl-acrylic and all-acrylic latexes and facilitated film formation in the absence of coalescing solvents. Lesquerella and vemonia methacrylate macromonomers were synthesized and formulated into environmentally friendly UV cured coatings. The lesquerella and vemonia modified coatings exhibited good gloss, pencil hardness, and adhesion to steel substrates. 

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