Acrylics polymerization

Acrylate polymerizations are markedly inhibited by oxygen therefore, considerable care is taken to exclude air during the polymerization stages of manufacturing. This inhibitory effect has been shown to be caused by copolymerization of oxygen with monomer, forming an alternating copolymer (81,82). 

Since acrylic polymerizations liberate considerable heat, violent or mnaway reactions are avoided by gradual addition of the reactants to the kettie. Usually the monomers are added by a gravity feed from weighing or measuring tanks situated close to the kettie. The rate of monomer addition is adjusted to permit removal of heat with full flow of water in the condenser and a partial flow in the cooling jacket. Flow in the jacket can be increased to control the polymerization in cases of erroneous feed rates or other unexpected circumstances. A supply of inhibitor is kept on hand to stop the polymerization if the cooling becomes inadequate. 

Furfural — see Furan-2-oarbaldehyde, 532 Furfuryl acetate, o -(butoxycarbonyl)-anodic oxidation, 1, 424 Furfuryi acrylate polymerization, 1, 279 Furfuryl alcohol configuration, 4, 544 2-Furfuryl alcohol polyoondensation, 1, 278 reactions, 4, 70-71 Furfuryl alcohol, dihydro-pyran-4-one synthesis from, 3, 815 Furfuryl alcohol, tetrahydro-polymers, 1, 276 rearrangement, 3, 773 Furfuryl chloride reactions... 

Copolymerization of macromonomers formed by backbiting and fragmentation is a second mechanism for long chain branch formation during acrylate polymerization (Section 4.4.3.3). The extents of long and short chain branching in acrylate polymers in emulsion polymerization as a function of conditions have been quantified.20 ... 

A few studies have appeared on systems based on persistent nitrogen-centered radicals. Yamada et al.2"1 examined the synthesis of block polymers of S and MMA initiated by derivatives of the triphenylverdazyl radical 115. Klapper and coworkers243 have reported on the use of triazolinyl radicals (e.g. 116 and 117). The triazolinyl radicals have been used to control S, methacrylate and acrylate polymerization and for the synthesis of block copolymers based on these monomers [S,243 245 tBA,243 MMA,243 245 BMA,245 DMAEMA,24 5 TMSEMA,247 (DMAEMA-Wbc/fc-MMA),246 (DMAEMA-Woc -S)246 and (TMSEMA-6/ocfc-S)247]. Reaction conditions in these experiments were similar to those used for NMP. The triazolinyl radicals show no tendency to give disproportionation with methacrylate propagating radicals. Dispcrsitics reported arc typically in the range 1.4-1.8.2"43 246... 

Formaldehyde-to-phenol ratios, 404 V-Formyl amines, 158 Fourier transform infrared (FTIR) spectrometry, 116, 300, 387, 407-408 Fradet, Alain, 17 Free-radical copolymerization, 59 Friedel-Crafts acrylation polymerization, 332-334... 

Acrylic Polymerization Model. Acrylic polymers are known to have excellent weathering and functional properties as binders for coatings, and they are widely used in the coatings as well as many other industries. To obtain the desirable property/cost balance, random copolymers instead of blends of homopolymers are frequently used. 

Our acrylic polymerization model was developed to meet the need for solving these problems. Kinetics used are based on fairly well accepted and standard free radical polymerization mechanisms. 

Application of the Solvent Formulation System. In contrast to the acrylic polymerization model discussed previously which is extremely complex mathematically and computation wise the solvent formulation system is a growing collection of models which are much less complex mathematically and computation wise. However, the system does allow one to evaluate many properties of solvent blend quickly and with relative ease. The system has been found to be valuable in ... 

The author would like to acknowledge the help provided by Dr. R. G. Lindsey 1n the preparation of this paper by sharing h1s experience 1n the development and application of the acrylic polymerization model. He would also like to thank the E. I. Du Pont De Nemours Co. for permission to publish this paper. 

Acrylic polymerization model capability, 172,173f description, 172... 

Difunctional vinvl ether/difunctional N-maleimide. Up until this point, our results have centered on the reactivity of monofunctional maleimide divinyl ether mixtures. From Kloosterboer s26 work for acrylate polymerization, it is known that the rate of polymerization of a free-radical process is increased dramatically as the functionality of the acrylate is increased. In order to enhance the polymerization rates of maleimide divinyl ether systems, it was decided to synthesize difimctional maleimides for copolymerization with difunctional vinyl ethers. The results in Table V indicate that the photoinitiated TTDBM [bismaleimide made from maleic anhydride and 4,7,10-... 

Figure 16 Examples of aluminum alkyls used for acrylate polymerization.

Balchan, A. S., D. A. Paquet, and J. A. Klien (1999). "Emergency Relief Adequacy for Acrylic Polymerization Processes." Process Safety Progress 18, 2 (Summer), 71-77. 

The same type of addition—as shown by X-ray analysis—occurs in the cationic polymerization of alkenyl ethers R—CH=CH—OR and of 8-chlorovinyl ethers (395). However, NMR analysis showed the presence of some configurational disorder (396). The stereochemistry of acrylate polymerization, determined by the use of deuterated monomers, was found to be strongly dependent on the reaction environment and, in particular, on the solvation of the growing-chain-catalyst system at both the a and jS carbon atoms (390, 397-399). Non-solvated contact ion pairs such as those existing in the presence of lithium catalysts in toluene at low temperature, are responsible for the formation of threo isotactic sequences from cis monomers and, therefore, involve a trans addition in contrast, solvent separated ion pairs (fluorenyllithium in THF) give rise to a predominantly syndiotactic polymer. Finally, in mixed ether-hydrocarbon solvents where there are probably peripherally solvated ion pairs, a predominantly isotactic polymer with nonconstant stereochemistry in the jS position is obtained. It seems evident fiom this complexity of situations that the micro-tacticity of anionic poly(methyl methacrylate) cannot be interpreted by a simple Bernoulli distribution, as has already been discussed in Sect. III-A. 

Fig. 3-12 Plots of w(log M) (solid plot) and dw(log M)ld log M (dotted plot) versus log M for dodecyl acrylate polymerization at —4°C and 200 bar in 36 wt% CO2. w is the weight fraction of polymer having molecular weight M. After Beuermann and Buback [2002] by permission of Elsevier, Oxford an original plot, from which this figure was drawn, was kindly supplied by Dr. S. Beuermann.

Group transfer polymerization allows the synthesis of block copolymers of different methacrylate or acrylate monomers, such as methyl methacrylate and allyl methacrylate [Hertler, 1996 Webster and Sogah, 1989]. The synthesis of mixed methacrylate-acrylate block copolymers requires that the less reactive monomer (methacrylate) be polymerized first. The silyl dialkylketene acetal propagating center from methacrylate polymerization is more reactive for initiation of acrylate polymerization than the silyl monoalkylketene acetal propagating center from acrylate polymerization is for initiation of methacrylate polymerization. Bifunctional initiators such as l,4-bis(methoxytri methyl si loxymethylene)cyclohexane (XXXIII) are useful for synthesizing ABA block copolymers where the middle block is methacrylate [Steinbrecht and Bandermann, 1989 Yu et al., 1988]. 

The kinetics of acrylate polymerization using this type of initiators have also been studied [ 172,177] in addition to allowing comparison of the effectiveness of different initiators, the kinetic behavior also provides support for a 2P mechanism for initiation with excitation in the visible and near-infrared range. The rate of a radical polymerization, Rp, is given by [178] ... 

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