Methacrylate macromonomers methacrylic acid

To the first category belong the homo- and copolymerization of macromonomers. For this purpose, macromolecules with only one polymerizable end group are needed. Such macromonomers are made, for example, by anionic polymerization where the reactive chain end is modified with a reactive vinyl monomer. Also methacrylic acid esters of long-chain aliphatic alcohols or monofunctional polyethylene oxides or polytetrahydrofurane belong to the class of macromonomers. 

The stable polymer dispersions with small-sized polymer particles of diameter >60 nm were prepared by dispersion copolymerization of PEO-MA macromonomer with styrene, 2-ethylhexyl acrylate, acrylic and methacrylic acids, and butadiene at 60 °C [79]. The particle size was reported to decrease with increasing macromonomer fraction in the comonomer feed. Besides, it varied with the type of the classical monomer as a comonomer. Tg of polymer product was found to be a function of the copolymer composition, the weight ratio macromonomer/monomer, and monomer type and varied from 50.6 to 220.4 °C. 

The synthesis of MA-PIB macromonomers by three different methods, which were claimed to be less cumbersome than that above, was reported by Maenz and Stadermann [105]. The first procedure, as shown in Scheme 12, involved alkylation of phenol by PIB olefin followed by reaction with methacrylic acid. 

The latex particle diameter produced in the emulsion copolymerization of styrene with partially neutralized poly(methacrylic acid) macromonomers, 48, was studied as a function of degree of neutralization [127]. The latex particle... 

In another method Gramain and Frere 34 reacted Polyoxyethylene monomethyl ether with methacryloyl chloride under various experimental conditions. The reaction was carried out in the presence of a tertiary amine and yielded the expected macromonomers. Care was taken to avoid two possible side reactions, namely addition of HC1 to the double bond, and polymerization of the methacrylic acid derivatives. Applying appropriate reaction conditions, the authors obtained oo-methacryloyl PEO macromonomers quantitatively. 

It seems that instead protonated species (anhydride or ester molecules) play a major role in the process. The protons originate from some added acid (e.g. acrylic or methacrylic acid). The characterization of the formed macromonomers revealed that the number of ester functions per molecule is close to 2. The role of the protons is evidenced by the increase of the reaction rate with increasing amount of methacrylic acid in the system. In the absence of a protonic acid high molecular weight poly-THF is produced, no anhydride is consumed and reshuffling does not take place. This mechanism which remains to be confirmed is in any case completely different from the inifer -type cationic transfer which may occur with unsaturated monomers. It is discussed in the next section. 

Watanabe62) studied systematically the copolymerization of ra-methacryloyl-polyoxyethylenes, with monomers such as acrylonitrile, styrene, butyl methacrylate, and methacrylic acid. It should be mentioned that the macromonomers that he prepared are very short so that no difficulties were encountered to isolate the graft copolymers formed. There are many applications for these graft copolymers, e.g. as additives in polyacrylonitrile films and fibers they cause improved antistatic properties. They have been tested as varnishes, coatings, and wood dimensional stabilization agents. 

Yamashita et al.2,99) also investigated the copolymerization of PMMA macromonomers both with a mixture of HEMA and perfluoroalkyl acrylate and with a MMA-methacrylic acid mixture here again, the PMMA grafts originating from the macromonomer play the role of anchoring segments, and surface accumulation of the functional backbone segments is well established. 

Monofunctional polymers of A -t-butylaziridine containing polymerizable group (macromonomers) were prepared by initiation of the polymerization with methyltriflate and termination with methacrylic acid [168]. 

Macromonomers were prepared by polymerizing oxazolines with monofunctional initiators (e.g., methyl p-toluenosulfonate) and terminating the polymerization with salts of acrylic or methacrylic acid. Macromonomers with M varying from M — 500 to —2500 and MJM - 1.2-1.4 were obtained functionalities, however, depended strongly on reaction conditions and the values between 0.99 down to —0.5 and lower were reported [280]. 

The macromonomers were prepared by anionic polymerization of 2-vinylpyridine followed by reaction with ethylene oxide and methacrylic acid chloride [111] as shown in Scheme 1. MALDI-TOF mass spectroscopy was utilized in order to determine the absolute molar mass and the degree of end-functionalization as given in Table 4. The sample code MM-PVPXY comprises the polymerizable unit (MM=methacrylate), the side chain (PVP=polyvinylpyridine) and the side chain degree of polymerization XY. 

In a more specific example, macromonomer composed of n-butyl methacrylate and methacrylic acid prepared by CCT was copolymerized with n-butyl acrylate containing a small portion of methyl methacrylate.341 Comparison to the equivalent copolymer made with a macromonomer prepared with a thiol chain-transfer agent demonstrated that the CCT macromonomer formed a copolymer while the thiol macromonomer did not. When these compositions were cured using trifunctional isocyanates, they were useful as both clear and pigmented automotive finishes. 

Poly(2-alkyl oxazoline)s having methacrylate or acrylate end groups were prepared by two methods [182]. a) Living polyoxazoline chains, prepared using methyl p-toluene sulphonate as initiator, were end-capped by reaction with metal salts or tetraalkylammonium salts of acrylic or methacrylic acid or a trialky-lammonium salt or trimethylsilyl ester of methacrylic acid (functional termination). b) The living polymers were terminated with water in the presence of Na2C03 to provide hydroxyl-terminated chains. Subsequent acylation with acry-loyl or methacryloyl chloride in the presence of triethylamine led to the formation of the macromonomers. The procedures are outlined in the following Scheme 51. 

Block-Type Brushes by Sequential Polymerization The sequential hving polymerization of two macromonomers or a macromonomer with a conventional comonomer forms either block-block- or block-coil-type brush structures. For example, giant rod-coil amphiphilic block copolymer bmshes were prepared via a stepwise metallocene-catalyzed polymerization [58]. In the first step, a concentrated solution of methacryloyl end-functionalized PS macromonomer (DP = 18.3, MWD = 1.05) was polymerized by the organosamarium(iii) catalyst in THF. After PS macromonomer was completely consumed, the active center remained living, and tert-butyl methacrylate tert-butyl methacrylate (tBMA) as a comonomer was added to grow the second block. After termination by ethanol, the poly(tert-butyl methacrylate) (PtBMA) coil block was hydrolyzed into a hydrophihc block, poly(methacrylic acid) (PMAA). The final product consisted of a hydrophobic PS brush block and a hydrophihc PMAA coil. The hydrophilic PMAA coil collapsed in nonpolar solvents, which forced the block-coil CPBs to self-assembled into giant micelles with PMAA as the core component and the stiff PS brush block as the shell to stabihze the micelles. 

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). 

Termination of the cationic ring-opening polymerization of N-t-butylaziridine with methacrylic acid irields macromonomers (531). 

Biodegradable comb-like polymer prepared by free radical copolymerization of PLA macromonomer with vinyl (A-vinylpyrrolidone) and acrylic monomers (MMA, methacrylic acid (MA)) has been reported [86]. The hydroxyl group of poly(2-hydroxyethyl methacrylate) (HEMA) anchored to a gold surface-initiated ROP of lactide using Sn (Oct)2 as a catalyst. The final structure of the polymer is a surface-anchored poly(hydroxyethyl methacrylate)-g-poly-lactide, to yield an overall structure of a bottlebrush [87]. 

An alternative (and perhaps more efficient) polymeric surfactant is the am-phipathic graft copolymer consisting of a polymeric backbone B (polystyrene or poly(methyl methacrylate)) and several A chains ( teeth ) such as poly(ethylene oxide). The graft copolymer is referred to as a comb stabiliser - the polymer forms a brush at the solid/liquid interface. The copolymer is usually prepared by grafting a macromonomer such as methoxy poly(ethylene oxide) methacrylate with poly(methyl methacrylate). In most cases, some poly(methacrylic acid) is incorporated with the poly(methyl methacrylate) backbone - this leads to reduction of the glass transition of the backbone, making the chain more flexible for adsorption at the solid/liquid interface. Typical commercially available graft copolymers are Atlox 4913 and Hypermer CG-6 supplied by ICI. 

In a recent study, Tuncel and Serpen [86] used a macromonomer of a very short polyoxyethylene chain (n = 3) and an ethyl methacrylate polymerizable group, which was applied to emulsion copolymerization of styrene and methacrylic acid. The effects of concentrations of reactants on the particle size and on the polymerization rate were studied in detail, but no data concerning the stability of the latexes have been reported. 

Colloidal photonic crystals are often synthesized from monodisperse microspheres of PMMA, PS, and silica. The use of functionalized microspheres can increase the performance of certain photonic devices and CCTP has been successful in the synthesis of NC-loaded photonic crystals with a polymerizable macromonomer. Monodisperse microspheres composed of a PS core with a poly(methacrylic acid) (PMAA) shell were synthesized through an emulsion copolymerization of PMAA macromonomers synthesized by CCTP with PS. It was found that the CdZnS NCs capped with PMAA macromonomers could be anchored to the microsphere surface as the PMAA acts as a ligand. These colloidal crystals are then formed into a film, yielding well-ordered, hexagonal close packed structures that show pH-responsive behavior. All films with different hydrodynamic diameters simultaneously exhibit brilliant colors from red to blue, providing a promising avenue for the next generation of photonic devices. 

Functional monomer or macromonomer Carboxylic acids (acrylic and methacrylic acids) COOH Blackley (1983)... 

Termination of the cationic ring-opening polymerization of iV-t-butylaziridine with methacrylic acid yields macromonomers according to equation (20). Because N-t-butylaziridine is sterically hindered, polymerization is not complicated by the transfer reaction of two growing chains that results in one chain growing in two directions and one dead chain. 

The emulsion copolymerization of styrene and methacrylic acid in the presence of a new polymerizable macromonomer based on PEG as stabilizer is proposed by Hincel and Serpen [55] to obtain larger and more surface-carboxyl-charged monodisperse particles relative to those obtained by the same emulsifier-free emulsion copolymerization. 

Sinnwell et al. (2006) demonstrated ring-opening polymerization of s-caprolactone under microwave irradiation in the present of methacrylic acid. From this process, they obtained radical polymerizable polyester macromonomers. This process required only one step and high functionality. The melting point of the macromonomers was between 46 and 51°C. 

Xi and co-workers [52] prepared methacrylate-functionalized dendritic macromonomers by conversion of the hydroxymethyl group of the polyether dendron to the corresponding bromide and then functionalization with methacrylic acid. Free-radical polymerization of the macromonomer corresponding to a second-generation dendron resulted in formation of a relatively low molecular weight product (X = 6-7). 

A methacryl-type polyester macromonomer was synthesized by lipase PF-catalyzed polymerizahon of DDL using vinyl methacrylate as terminator ( terminator method ), in which the vinyl ester terminator was present from the beginning of the reachon (Scheme 17). In using divinyl sebacate as terminator, the telechelic polyester having a carboxylic acid group at both ends was obtained. Various non-protected thiol compounds were used as inihator or terminator for the thiol end-funchonalizahon of poly(8-CL). ... 

Of course, it is possible to first copolymerize the macromonomer and vinyl monomer and then use this as a stabilizer in dispersion polymerization. As mentioned earlier, HSM is a stabilizer copolymerized from a methyl methacrylate and a macromonomer that is a maleic ester of 12 hydroxystearic acid pentamer (17). 

The graft copolymers were already used for preparation and stabilization of polymer particles by Barrett [1]. He synthesized a poly(12-hydrostearic acid) macromonomer with a methacrylate end group. This macromonomer was copolymerized with MMA to obtain a preformed comb-graft copolymer, which was successfully used as stabilizer in nonaqueous dispersions of MMA. 

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