Methylmethacrylate radical polymerization

Lachinov, M. B. Dreval, V. E. Kasarkin, V. A. Simonyan, R. A. Shipulina N. L Zubov V. P. Kabanov, V. A. The intercommunication of structure formation and kinetics of methylmethacrylate radical polymerization at ZnCl presence at large conversion degrees. High-Molecular Compounds, A, 1977,19(4), 741-749. 

A radical initiator based on the oxidation adduct of an alkyl-9-BBN (47) has been utilized to produce poly(methylmethacrylate) (48) (Fig. 31) from methylmethacrylate monomer by a living anionic polymerization route that does not require the mediation of a metal catalyst. The relatively broad molecular weight distribution (PDI = (MJM ) 2.5) compared with those in living anionic polymerization cases was attributed to the slow initiation of the polymerization.69 A similar radical polymerization route aided by 47 was utilized in the synthesis of functionalized syndiotactic polystyrene (PS) polymers by the copolymerization of styrene.70 The borane groups in the functionalized syndiotactic polystyrenes were transformed into free-radical initiators for the in situ free-radical graft polymerization to prepare s-PS-g-PMMA graft copolymers. 

Figure 31 The radical initiator (47) based on the oxidation adduct of an alkyl-9-BBN used for the production of poly(methyhnethacrylate) (48) from methylmethacrylate monomer by the radical polymerization route. (Adapted from ref. 69.)...

He also prepared a poly(styrene-g-styrene) polymer by this technique [114], The lack of crosslinking in these systems is indeed proof of the control achieved with this technique. An eight-arm star polystyrene has also been prepared starting from a calixarene derivative under ATRP conditions [115]. On the other hand, Sawamoto and his coworkers used multifunctional chloroacetate initiator sites and mediation with Ru2+ complexes for the living free-radical polymerization of star poly(methylmethacrylate) [116,117]. More recent work by Hedrick et al. [84] has demonstrated major progress in the use of dendritic initiators [98] in combination with ATRP and other methodologies to produce a variety of structure controlled, starlike poly(methylmethacrylate). 

The formation of syndiotactic polymethylmethacrylate is the result of the prefered chain configuration in the free anionic polymerization, similar to the formation of syndiotactic structure by the free radical polymerization of methylmethacrylate. Bawn, James and North (77)... 

Idemitsu Kosan in Chiba, Japan, operates a pilot plant for the free radical polymerization of methylmethacrylate (MMA) [54], following prior process development at Kyoto University [55]. 

In contrast, recent kinetic investigation of the polymerization of spacerless G2 dendron-substi-tuted styrene and methylmethacrylate, respectively, in solution lead to the unexpected conclusion that above a certain critical monomer concentration a strong increase in the rate of the free radical polymerization is observed [21]. The results can be explained by self-organization of the growing polymer chain to a spherical or columnar superstructure in solution, depending on the degree of polymerization (DP, Fig. 2). The rate constants and low initiator efficiency lead one to conclude that the self-assembled... 

To make nanoparticles able to escape complement activation, Passirani et alJ" proposed to coat nanospheres with heparin. This compound, which is a polysaccharide, is a physiological inhibitor of complement activation in vivo. Heparin-coated poly(methylmetha-crylate) nanoparticles were prepared by emulsion polymerization. In the method, the radical polymerization of methylmethacrylate was initiated by heparin according to an original method involving cerium ions and allowing heparin to covalently attach to poly(methyl-methacrylate). 

A few other methods have been used to prepare polypeptide hybrid copolymers. Inoue polymerized Bn-Glu NCA off of amine-functionalized styrene derivatives, and then copolymerized these end-functionalized polypeptides with either styrene or methyl methacrylate using free radical initiators to yield hybrid comb architecture copolymers [38]. Although unreacted polypeptide was identified and removed by fractionation, copolymers were obtained with polypeptide content that increased with feed ratio. There was no mention if the polypeptide interfered with the radical chemistry. In similar work, Imanishi and coworkers converted the amine-ends of polypeptides to haloacetyl groups that were used to initiate the free radical polymerization of either styrene or methylmethacrylate to yield hybrid block copolymers [39]. Studies using CPC showed that the crude product contained mixtures of copolymers and homopolymers, and so removal of the homopolymers by extraction was necessary. 

The porphyrin cobalt complex in radical polymerization of methylmethacrylate catalyzes the chain transfer to the monomer without affecting the polymerization rate. The phthalocyanine cobalt complex catalyzes the chain termination. 

Classification by Decomposition Behavior. The decomposition mechanism is a reasonable way to classify polymers. They can either depolymerize upon irradiation, for example, poly(methylmethacrylate), or decompose into fragments such as poly-imides or polycarbonates. This method of classification is closely related to the synthesis of polymers. Polymers that are produced by radical polymerization from monomers, which contain double bonds, are likely to depolymerize into monomers, while polymers that have been formed by reactions like polycondensation will not depolymerize into monomers upon irradiation, but will be decomposed into different fragments. The second group cannot be used to produce films with the same structure or molecular weight as the original material with methods such as PLD. 

It must be noted that the process of seeded emulsion polymerization does not lead to an equilibrium structure. Hence, the sharp interface between PS and PMMA observed in the above core-shell particles cannot be explained by thermodynamic arguments. A possible mechanism maybe sought in the adsorption of oligo(methylmethacrylate) radicals from the water phase onto the PS-seed particles [45]. The temperature of the seeded emulsion polymerization (80 °C [45]) is well below the glass transition temperature of polystyrene and the adsorbed chains bear a sulfate endgroup. The adsorbed oligomers will therefore remain at the surface of the core particles and in consequence there is no extended interface between PS and PMMA in these. particles. 

The use of organometallic compounds as chain-transfer catalysts in free-radical polymerization has been widely studied. One objective is the production of polymers with terminal vinyl groups and lower molecular weight components compared with polymerization in the absence of chain-transfer catalysts. Gomplexes of cobalt(ii) have been used as effective catalysts, but the instability of the intermediate cobalt hydride does not permit firm establishment of the reaction mechanism. To address this issue, several chromium compounds have been applied as catalysts for the polymerization of methylmethacrylate (MMA) and styrene. The temperature dependence of the rate constant for free-radical polymerization of MMA for catalyzed chain transfer by (GsPh5)Gr(GO)3 has been determined using the Mayo equation. ... 

The graft copolymer products, poly(met)acrylates branched to polyester-suUbnes, can be produced next way [200]. Firstly, the polyestersulfone is being chlormethylenized by monochlordimethyl ester. The product is used as macrostarter for the graft radical polymerization of methylmethacrylate (I), methylacrylate (II) and butylacrylate (III) in dimethylformamide according to the mechanism of transferring of atoms under die influence of the catalytical system FeCyisophthalic acid. The branched copolymer with I has only one glassing temperature while copolymer with II and III has three. 

Those radicals initiate polymerization of vinyl monomers. For example, methylmethacrylate is polymerized by the benzoin radical as follows ... 

In more recent years, the radical polymerization of several methacrylates was studied in a counterrotating twin-screw extruder (6-9). Stuber and Tirrel (6) and Dey and Biesenberger (7) studied the radical polymerization of methylmethacrylate, Ganzeveld and Janssen (8) described the polymerization of -butylmethacrylate, while Jongbloed et al. (9) also studied a copolymerization of butylmethacrylate and 2-hydroxy-propylmethacrylate. 

Alipour, M., et al. (2001). Living radical polymerization of methylmethacrylate, methylacrylate and their block copol5mers with acrylonitrile by atom transfer radical polymerization. Iran Polym. J., 10(2) 99-106. 

As mentioned above, the cleavage of Si-Si-bonds in polysilanes upon irradiation with UV-light is very efficient and results in the formation of silicon radicals. These radicals react with olefins to initiate radical polymerizations. Especially the polymerization of methylmethacrylate and styrene with a variety of polysilanes as photoinitiators has been studied in detail [104]. The advantage of this kind of initiation is the possibility to prepare polysilane-polyolefin hybrids [105]. All modifications of radical polymerizations, such as the atom transfer radical polymerization (ATRP), are possible with polysilanes as photoinitiators [106]. 

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