Monomer yield

Polymerization of styrene or methyl methacrylate by macroazoinimers having two vinyl groups (MIM-2v) resulted in crosslinked block copolymers, while macroazoinimers with one vinyl end (MIM-1 v) group to polymerize vinyl monomers yielded branched block copolymers. 

Homopolymerization of macroazoinimers and co-polymerization of macroinimers with a vinyl monomer yield crosslinked polyethyleneglycol or polyethyleneglycol-vinyl polymer-crosslinked block copolymer, respectively. The homopolymers and block copolymers having PEG units with molecular weights of 1000 and 1500 still showed crystallinity of the PEG units in the network structure [48] and the second heating thermograms of polymers having PEG-1000 and PEG-1500 units showed that the recrystallization rates were very fast (Fig. 3). 

Hepuzer et al. [91] have used the photoinduced homolytical bond scission of ACPB to produce styrene-based MAIs. These compounds were in a second thermally induced polymerization transferred into styrene-methacrylate block copolymers. However, as Scheme 24 implies, benzoin radicals are formed upon photolysis. In the subsequent polymerization they will react with monomer yielding nonazofunctionalized polymer. The relatively high amount of homopolymer has to be separated from the block copolymer formed after the second, thermally induced polymerization step. 

In the same way, the addition of monomer yields the radical ions which possess the most stable carbanion ends and the most stable radical ends, e.g.,... 

The difficulties encountered in the early studies of anionic polymerization of methyl methacrylate arose from the unfortunate choice of experimental conditions the use of hydrocarbon solvents and of lithium alkyl initiators. The latter are strong bases. Even at —60 °C they not only initiate the conventional vinyl poly-addition, but attack also the ester group of the monomer yielding a vinyl ketone1, a very reactive monomer, and alkoxide 23). Such a process is described by the scheme. 

Okamoto and his colleagues60) described the interesting polymerization of tri-phenylmethyl methacrylate. The bulkiness of this group affects the reactivity and the mode of placement of this monomer. The anionic polymerization yields a highly isotactic polymer, whether the reaction proceeds in toluene or in THF. In fact, even radical polymerization of this monomer yields polymers of relatively high isotacticity. Anionic polymerization of triphenylmethyl methacrylate initiated by optically active initiators e.g. PhN(CH2Ph)Li, or the sparteine-BuLi complex, produces an optically active polymer 60). Its optical activity is attributed to the chirality of the helix structure maintained in solution. 

No. Carboxylic acid Olefin Additive monomer (%-yield) Additive dimer (%-yield) Ref. 

However, the mechanism of action of filtration control additives is not yet completely understood. Examples are bentonite, latex, various organic polymers, and copolymers. Many additives for fluid loss are water-soluble polymers. Vinyl sulfonate fluid loss additives based on the 2-acrylamido-2-methyl-propane sulfonic acid (AMPS) monomer are in common use in field cementing operations [363]. The copolymerization of AMPS with conjugate monomers yields a fluid loss agent whose properties include minimal retardation, salt tolerance, high efficiency, thermal stability, and excellent solids support. 

Sample Total Lignin CaCl Monomer Monomer Yield... 

Latex or emulsion polymers are prepared by emulsification of monomers in water by adding a surfactant. A water-soluble initiator is added, e.g., persulfate or hydrogen peroxide (with a metallic ion as catalyst), that polymerises the monomer yielding polymer particles, which have diameters of about 0.1 pm. The higher the concentration of surfactant added, the smaller the polymer particles. 

When this decomposition occurs the degradation does not give high monomer yields (compared with un-zipping) the products tend to be low MW products. The chain scission and propagation is inhibited by free radical traps (see anti-oxidants). 

Copolymerization. Chain copolymerization, the polymerization of a mixture of two monomers, yields a copolymer with two different repeating units distributed along the polymer chain... 

Polymerization in which a cyclic monomer yields a monomeric unit whieh is acyclic or contains fewer cycles than the monomer. 

M.P. Krafft, L. Schieidknecht, P. Marie, F. Giulieri, M. Schmutz, N. Poulain, E. Nakkache, Fluorinated vesicles allow intrabilayer polymerization of a hydrophobic monomer, yielding polymerized microcapsules, Langmuir 17 (2001) 2872-2877. 

Fig. 10 Synthesis of a mixed brush may be accomplished by two strategies (a) A free radical initiator with low efficiency is used. This guarantees that some of the initiator is left after deposition of the first brnsh. Immersion into a second monomer yields a mixed brush where the two polymers are intercalated between each other, (b) A mixed monolayer could be used whereby A and B may be initiated independently (e.g. one is a photoinitiator and the other is a thermal initiator)...

Ni phosphorus-ylide complexes were reported by Ittel and co-workers to be active for the co-polymerization of ethylene and non-vinyl-functionalized monomers, yielding functionalized polyethylenes (PEs). These results demonstrate the high potential of late transition metal complexes for the production of co-polymers from hydrocarbon and polar monomers. 

Polypropylene (PP) is a semicrystalline commodity thermoplastic produced by coordination addition polymerization of propylene monomer [197]. Most frequently, stereospecific Ziegler-Natta catalysts are used in industrial processes to produce highly stereospecific crystalline isotactic (iPP) and syndiotactic (sPP) polymer with a small portion of amorphous atactic PP as a side product. Polymerization of non-symmetrical propylene monomer yields three possible sequences however, the steric effect related to the methyl side group highly favors the head-to-tail sequence. The occurence of head-to-head and tail-to-tail sequences produces defects along the PP chain [198]. Presence of such defects affects the overall degree of crystallinity of PP. 

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