Polymerization methylmethacrylate

A monomer called methylmethacrylate polymerizes to form an addition polymer that is used to make bowling balls. What is the name of this polymer ... 

The choice of the initiator best suited for a given polymerization is of great importance. Fast initiation requires that the nucleophilicity of the initiator be high enough for the monomer to be polymerized. However too high a nucleophilicity sometimes increases the probability of side reactions. For example, cumylpotassium is well suited to initiate the polymerization of styrene if the same initiator is used for methylmethacrylate polymerization, a side reaction on the ester carbonyl is likely to occur. Diphenylmethylpotassium, a much weaker nucleophile, is still an efficient initiator for methylmethacrylate, without side reaction, but it is unable to initiate rapidly and quantitatively the polymerization of styrene. 

Evidence for such reactions in methylmethacrylate polymerizations was obtained by termination of polymerizations with acetic acid followed by measurements of methanol formed (119, 120). Fig. 6 shows typical results obtained. It is assumed that the methanol found corresponds to lithium methoxide in the reaction mixture. Some methanol might in fact be produced only in the termination reaction from pseudo-cyclized species (cf. p. 82). In addition the tertiary alkoxides formed by attack of the initiator or growing polymer chains on the carbonyl group of the monomer might not eliminate lithium methoxide immediately but would do so on termination with acetic acid. In any case much of the methanol formed corresponds to actual alkoxide in the reaction mixture and the results give a minimum value of the concentration of species inactive in polymerization. For brevity it will be referred to as lithium methoxide. 

Methylmethacrylate polymerizes quickly. The sample must be collected without headspace, refrigerated, and analyzed immediately. 

Fig. 19. Temperature dependence of ftp for methylmethacrylate polymerization in toluene, (o) Initiated by diphenylhexyllithium [174] (+) initiated by butyl-lithiumdiethylzinc [180] ( ) initiated by fluorenyllithium [170] (0.1% THF present).

Ruby laser with 1=10 19+20 photons/(cm 2.s) is used to stimulate methylmethacrylate polymerization in AIBN and diacetyl presence [14,19,32].The authors do attempt to explain the obtained experimental data without considering the specificities and pecularities of high intensive light beam + matter interaction. We assume that such approach is not correct. 

Vanadium.—VO(acac)2CI (acac = acetylacetone) is a photo-initiator for methylmethacrylate polymerization both in the absence17 and in the presence175 of electron donors D, such as dimethyl sulphoxide or pyridine. Reactions (1) and... 

Adebekun, A. K. and Schork, F. J. (1989b) Continuous solution polymerization reactor control. 2. Estimation and nonlinear reference control during methylmethacrylate polymerization, Ind. Eng. Chem. Res. 28, 1846-61. 

A model for methylmethacrylate polymerization has been proposed by Benson and North [62] in 1959. According to this model the constant rate of chain termination is limited by the segmental difliision and depends upcm the length / of an interactive radical. A characteristic value L is introduced in the model and it is assumed that at the small lengths / of the chain the segmental diffusion depends on I and at the achievement of this characteristic value it becomes independent from /. 

The complex cw-[(OC)4Mo CNMeCH2CH2NMe 2] has been shown to be catalytically active in methylmethacrylate polymerization, and weakly active in the metathesis of octa-1,7-diene. Reactions of pentacarbonyltungstendi-phenylcarbene with cyclic enol ethers have been studied in a series of papers. ... 

Fig. 2 shows for instance the variation of the kinetic "constant" k for chain termination as a function of the concentration C of polymer, observed by Tirrel and Tulig, in the case of methylmethacrylate polymerization. When the concentration is high, k varies as C . This is due to the fact that the recombination of macroradicals is controlled by diffusion, which is slowed down by the viscosity increase. All kinetic parameters undergo similar changes. Such effects are very important in industrial reactors where the viscosity currently goes up by a factor of 10 during the reaction. In these conditions, one may wonder if the classical formalism for rates of elementary mechanisms is still adequate ... 

Graft polymerization of methylmethacrylate monomer onto pulps of different residual lignin contents using ceric ammonium nitrate as the initiator was carried out to study the influence of this residual lignin on the graft-ability of these pulps (Fig. 3). From this figure one can... 

For purposes of simulation and illustration we have chosen a batch reactor, solution polymerization of methylmethacrylate (MMA). Kinetic data were taken from Schmidt and Ray (1981) and thermodynamic data from Bywater (1955). We do not here consider the influence of diffusion control on the termination or other rate processes because such effects may be small when in a solution which is siifHciently dilute or when the polymer is of low molecular weight. 

All three monomers were soluble In the chromatographic mobile phase and standard analytical techniques were used for calibration. Solutions containing known quantities of monomer were chromatographed to establish a peak area concentration relationship for the appropriate detector. The homopolymer of methylacrylate was also soluble In the mobile phase. Thus, both UV and refractometer detectors were calibrated for polymerized methylmethacrylate by chromatographing solutions of PM ... 

An amide-type corrosion inhibitor is prepared as follows Methylmethacrylate is converted with tallow triamine or tallow tetramine at 80° to 90° C into the corresponding amides. After completion, the temperature is raised to initiate the polymerization reaction [1350]. The polymerization reaction is performed at temperatures up to 200° C. The polymer controls the corrosion of metal surfaces in contact with a corrosive hydrocarbon-containing medium. 

Although open tubular columns have been used for RPLC,42 most applications use packed columns. The most widely used column packings are formed by chemically bonding butyl (C4), octyl (C8), or octadecyl (C18) chains to a silica surface. Phenyl (Ph), cyano (CN), and amino (NH2) functionalities are also used. Polymeric packings which are finding broad acceptance include alkyl-grafted poly(methylmethacrylate) and alkyl-grafted or unmodified... 

Further examination of these reactivity and Q,e data allow for a clear understanding of the polymerization behavior and how it is modified by the phosphazene. Although most systems are best described by the terminal model, the reactivity patterns exhibited in the copolymerization of o-methylstyryl penta-fluorocyclophosphazene (6) with methylmethacrylate can only by quantitatively fit by a pennultimate model.14... 

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.)...

Several examples of ion-selective electrodes with ionophores covalently attached to a self-plasticized polymeric matrix have been reported in the literature. For instance, a Ca-selective electrode with the ionophore attached to a methylmethacrylate-co-decyl methacrylate backbone was developed recently [91]. Ion exchangers such as the dodecacarborane anion have been anchored to the polymeric backbone, with grafted dodecarborane showing greatly improved retention in the polymeric phase [88],... 

On the other hand, silicones are used in organic composites. The application of alloys composed of the fully cured silicone rubber particles in a continuous thermoplastic phase, called thermoplastic silicone vulcanizate, which offers high-performance materials, has been reported.506,507 Functionalized POSS was not only co-polymerized, but also blended with poly(methylmethacrylate) to study the effect of silsesquioxanes on the thermal stability of thermoplastics.508... 

Kreuter and Speiser [77] developed a dispersion polymerization producing adjuvant nanospheres of polymethylmethacrylate) (PMMA). The monomer is dissolved in phosphate buffered saline and initiated by gamma radiation in the presence and absence of influenza virions. These systems showed enhanced adjuvant effect over aluminum hydroxide and prolonged antibody response. PMMA particles could be distinguished by TEM studies and the particle size was reported elsewhere to be 130 nm by photon correlation spectroscopy [75], The particle size could be reduced, producing monodisperse particles by inclusion of protective colloids, such as proteins or casein [40], Poly(methylmethacrylate) nanoparticles are also prepared... 

The polymerization of olefinic compounds like acrylonitrile, vinyl chloride, styrene, methylmethacrylate can be initiated by anion. The mechanism, in general, can be given as... 

The anionic polymerization of methylmethacrylate at room temperature (originally called group transfer polymerization) [75-77] has provided a means for preparing star poly(methylmethacrylate) via the block polymerization with ethyleneglycoldimethacrylate ... 

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). 

---