Emulsion Polymerization of ethyl acrylate

Example C-tn-18 AE(50EO) for t ie emulsion polymerization of ethyl acrylate... 

Similar techniques have been used to incorporate silica into various polymers. (Mineral fillers are often given hydrophobic coatings to help in their dispersion in polymers such as polyolefins.60) Methacrylatopropyltrimethoxysi-lane has been used to add the methacrylate group on to silica. The treated silica was used in the emulsion polymerization of ethyl acrylate.61 Transparent films could be formed from the product. Living polystyrene was end-capped with a triethoxysilane (5.20), after which it was used to treat silica and alumina.62... 

Solution Copolymerization of Glycidyl Methacrylate and Styrene 41-8. Redox Emulsion Polymerization of Ethyl Acrylates 41-9. Preparation of Isotactic Poly(methyl methacrylate)... 

The control of the properties of polymers obtained by emulsion polymerization of ethyl acrylate by incorporating small amounts of functional groups or varying the conditions of polymerization is reported by Eliseeva [48] in 1979. 

Fig. 31. Polymerization of ethyl acrylate by wool swelling at 25° C using water as a swelling agent (60% aquesous emulsion with 3.2% Triton X-405) (105)...

The continuous bulk polymerization of methyl methacrylate was used as an example in Section 5.2. A stirred bulk polymerization like that used for styrene (Section 5.4) could be adapted for methyl methacrylate. A suspension process for poly(methyl methacrylate) was described in Section 5.4. The polymerization of ethyl acrylate most often is carried out in emulsion. A process such as that used for vinyl acetate is suitable (Section 16.4). Like vinyl acetate, the monomer is slightly water soluble, so true emulsion polymerization kinetics are not followed. That is, there is initiation of monomer dissolved in water in addition to that dissolved in growing polymer particles. Ethyl acrylate is distinguished by its rapid rate of propagation. Initiation of a 20% monomer emulsion at room temperature by the redox couple persulfate-metabisulflte can result in over 95% conversion in less than a minute. As with vinyl acetate polymerization, a continuous addition of monomer at a rate commensurate with the heat transfer capacity of the reactor is necessary in order to control the temperature. 

Emulsion Polymerization. Emulsion polymerization is the most important industrial method for the preparation of acryhc polymers. The principal markets for aqueous dispersion polymers made by emulsion polymerization of acryhc esters are the paint, paper, adhesives, textile, floor pohsh, and leather industries, where they are used principally as coatings or binders. Copolymers of either ethyl acrylate or butyl acrylate with methyl methacrylate are most common. 

Ethyl Acrylate (EA). Figure 7 shows the over-all reaction rate plotted logarithmically vs. time in case of the y-emulsion polymerization of EA. The function shows a very simple form from the beginning v r increases rather fast (in 6.5 minutes at 200 rad per hour) up to a maximum, and then decreases slowly without a period of zero order, following with considerable accuracy the first-order law with respect to [M]. At high conversions and very low reaction rates (about 0.05 mg. per minute per gram of emulsion), the curve falls less steeply. 

A recent paper by a Rusian team [18] describe tte use of a few new surfiners, one being cationic, namely JV-decylaceto-2-methyl-5 vinylpyridinium bromide (V), and the others being anioic, namely decyl (or dodecyl), sodium ethyl sulfonate, methacrylamides (VI), decyl (or dodecyl)-phenyl (Na or K sulfonate) acrylate (VII), and decyl ester of sodium (or K or NH4) sulphocin-namic acid (VIII). These surfmers were used for emulsion polymerization of styrene, butylacrylate or chloroprene, in the presence of KPS or AIBN without any other surfactants. It should be noted that the consumption of these surfactants take place early in the polymerization process which is faster than in... 

Copolymers containing allyl methacrylate have found application as an additive to other resin to enhance the properties of the system. For example, in one patent disclosure, an aqueous emulsion polymer was formed in water using 0.03 gm of sodium carbonate, 50 gm of methyl methacrylate, 2.0 gm of ethyl acrylate, and 0.1 gm of allyl methacrylate, and 0.40 gm of the sodium salt of an allyl Ci3-alkyl ester of sulfosuccinic acid. The polymerization was initiated with sodium persulfate and heated at 83°C for 1 hr. To this latex, 40 gm of butyl acrylate, 10 gm of styrene, 1.0 gm of allyl methacrylate, and another 0.40 gm of the above surfactant were added while polymerization continued. In a third... 

Muller and coworkers prepared disc-like polymer Janus particles from assembled films of the triblock copolymer SBM and, after hydrolysis of the ester groups into methacrylic acid units, used these as Pickering stabilizer in the soap-free emulsion polymerization of styrene and butyl acrylate [111]. Armes and coworkers described the synthesis of PMMA/siUca nanocomposite particles in aqueous alcoholic media using silica nanoparticles as stabilizer [112], extending this method to operate in water with a glycerol-modified silica sol [113, 114]. Sacanna showed that methacryloxypropyltrimethoxysilane [115] in the presence of nanosized silica led to spontaneous emulsification in water, which upon a two-step polymerization procedure afforded armored particles with an outer shell of PMMA [116]. Bon and coworkers demonstrated the preparation of armored hybrid polymer latex particles via emulsion polymerization of methyl methacrylate and ethyl methacrylate stabilized by unmodified silica nanoparticles (Ludox TM O) [117]. Performance of an additional conventional seeded emulsion polymerization step provided a straightforward route to more complex multilayered nanocomposite polymer colloids (see Fig. 14). 

Recently, Ye and DeSimone [40] showed that a diblock copolymer of a fluorinated acrylate and a glucose-containing hydrophilic block will support the emulsion polymerization of N-ethyl acrylamide in CO2. Here, the use of a fluorinated azo-initiator that partitions strongly to the CO2 phase (avoiding the monomer droplets) led to the generation of very fine (submicron) particles of polymer. Fluoroacrylates are known to be the most C02-philic materials found to date, and hence their use allows for achievement of the crucial phase behavior conditions shown in Fig. 7.2. 

Emulsion polymerization of pyrrole was also used to prepare blends of polypyrrole with a poly(alkyl methacrylate) [95]. A chloroform solution of a poly-(alkyl acrylate) and pyrrole was dispersed in an aqueous surfactant solution generating an emulsion. An aqueous solution of an oxidant was added to the emulsion with stirring, polymerizing pyrrole. The precipitated blend could be hot pressed in the form of films with conductivities of 6-7Scm . The curve for the variation of the conductivity of the blend with the oxidant/pyrrole ratio shows a maximum at a ratio of two with subsequent decrease. However, the yield increases to nearly 100% up to a ratio of four. The percolation threshold is approximately 10 wt% of pyrrole. The type and the concentration of the surfactant also affect the yield and conductivity. The mechanical properties of the blend depends on the number of carbons in the alkyl chain of the insulating polymer host. The strain at break of hot-pressed films increases and the stress at break decreases in the direction methyl, ethyl, butyl (Figure 18.3). This is an example where the mechanical properties of the conductive blend could be tailored according to the alkyl substituent in the poly(alkyl methacrylate) used in its preparation. 

Figure 11 Variation of -ln(l-c) normalized by the kinematic viscosity V and volume fraction of polymer (j) with the square root of power consumption for the stirred-reactor emulsion polymerization of vinyl chloride-ethyl acrylate mixtures according to Lowry et al. (15) using the data of ref. 17.

Figure 3.9. Rayleigh light scattering intensity versus time data obtained from the surfactant-free emulsion polymerizations of different monomers. The symbols MA, EA, and BA denote methyl acrylate, ethyl acrylate, and />butyl acrylate, respectively.

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