Transition metal polyacrylates

Polycondensation pol5mers, like polyesters or polyamides, are obtained by condensation reactions of monomers, which entail elimination of small molecules (e.g. water or a hydrogen halide), usually under acid/ base catalysis conditions. Polyolefins and polyacrylates are typical polyaddition products, which can be obtained by radical, ionic and transition metal catalyzed polymerization. The process usually requires an initiator (a radical precursor, a salt, electromagnetic radiation) or a catalyst (a transition metal). Cross-linked polyaddition pol5mers have been almost exclusively used so far as catalytic supports, in academic research, with few exceptions (for examples of metal catalysts on polyamides see Ref. [95-98]). 

Effect of Anions in Copper Compounds. Since the copper stearate was the most effective catalyst among the transition metal stearates for the early stage of the thermal oxidation of polypropylene, the effect of anions in copper compounds on the thermal oxidation of atactic polypropylene was examined. The oxygen uptake curves of the polymer in the presence of various copper compounds (acetate, propionate, butylate, stearate, laurate, polyacrylate, and cupric oxide) are shown in Figure 4. In the absence of the copper compounds, oxygen uptake of the polymer increases linearly with time. In the presence of copper compounds of fatty acids (acetate, propionate, butyrate, laurate, and stearate), the oxygen uptake of the polymer levels off at ca. 25-30 O2 mL/g polymer after... 

The pyrolysis of transition metal carboxylates (in the example of Ni " ) has an essential place due to both (a) the quantitative characteristics of the main stages and (b) the properties of the products obtained. Such metallopolymers can be prepared by two principally different routes by the above-mentioned polymer-analogous reactions, namely, by the interaction of polyacryhc acid with metal salts Ni, (PAA-Ni ), Co " ", Fe " ", and so on (method A), or by radical polymerization of the appropriated monomers—for example, nickel acrylate, [Ni(CH2CHCOO)2] , to give nickel polyacrylate (NiPAcr) (method C). The kinetic peculiarities of metallopolymers thermolysis were compared with the behavior of their low-molecular-weight analogues nickel propionate. 

Polypeptide-b-polyacrylate block copolymers have also been prepared by ATRP followed by synthesis of a transition metal macrocatalyst for controlled NCA polymerization. The same group, by combining living metathesis polymerization with subsequent preparation of a bifunctional NCA macrocatalyst and then growth of low-polydispersity protein blocks, demonstrated the preparation of ABA polypeptide-l7-synthetic-l7-polypeptide rod-coil-rod triblock copolymers. ... 

A wide range of acrylates with various side chains have been polymerized using ATRP to obtain well-de ned functional polymers, e.g., ATRP of 2-hydroxyethyl acrylate, glycidyl acrylate, and tert-butyl acrylate (yielding well-de ned poly(acrylic acid) on hydrolysis). Among several transition metal catalysts, viz., copper, ruthenium, and iron-based systems, which have been successfully used for the controlled ATRP of acrylates, copper appears to be superior in producing well-de ned polyacrylates with low polydispersities. 

The multicomponent ATRP system consists of an initiator (alkyl (pseudo)halide, RX), a redox-active transition metal in its lower oxidation state (M"), ligands, a deactivator (XM" species) and the monomer. ATRP is performed in bulk or in solution at elevated temperatures [288] with the possible use of different additives. One important item to regard is the fact that in ATRP one set of conditions cannot be applied to every monomer class. While neither polyacrylic nor poly(methacrylic) acid can be synthesized with currently available ATRP systems, because the monomers rapidly react with the metal complexes to form metal carboxylates, various acrylate esters can be polymerized by ATRP (Scheme 28) [289]. In analogy to these acrylate esters a wide range of methacrylate esters is expected to undergo ATRP. 

Different transition metal salts of acrylate polymerize at 60 °C with AIBN, e.g., in ethanol under dissociation-exeluding conditions [183,184]. The resulting metal-containing polymers are as expected insoluble in organic solvents but they are converted to soluble polyacrylic acid in a methanol-HCl mixture. The reactivity of the metal-acrylates in the homopolymerization decreases as follows Co(II) > Ni(II) > Fe(III) > Cu(II). 

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