Ethyl acrylate monomer, determination

Bentonite enriched in montmorillonite with 75meq/100g of cation exchange capacity, as determined in this laboratory, was provided by Linan Chemical Factory of Bentonite of Zhejiang Province. Ethyl acrylate monomer was purified by distillation under reduced pressure before use. All the water used was deionized. The initiator potassium persulfate (KPS) and the surfactant sodium dodecylsulphate (SDS) were used as supplied. 

The choice of acrylic ester, and hence its polarity, determines the low temperature flexibility, and the heat and chemical resistance of the polymer both alkyl and alkoxy acrylic esters are used as monomers. Within the alkyl acrylic esters, ethyl acrylate has the highest polarity and hence gives... 

A more conventional mechanism appears to be operative in the photopolymerization of ethyl acrylate [178] and methyl methacrylate [179] in aqueous solution, sensitized by fluorescein and Erythrosin, respectively. Ascorbic acid is the reducing agent in both cases and it is observed that the reaction does not proceed in the absence of buffer, usually phosphate buffer pH 6. Polymer formation starts after an induction period but its dependence on light intensity and ascorbic acid concentration has not been determined. The rate of photopolymerization is proportional to the monomer concentration and to the square root of the light intensity, dye, and ascorbic acid concentration. The authors report the order with respect to the monomer as 3/2. However, from our analysis of the data for fluorescein, which are more... 

Aqueous emulsions of styrene, methyl methacrylate, methyl acrylate, and ethyl acrylate were polymerized with y-radiation from a Co source in the presence of sodium dodecyl sulfate or sodium laurate. The continuous measurement of conversion and reaction rate was carried out dilato-metrically. The acrylates polymerized fastest and the over-all polymerization rate increased as follows styrene < methyl methacrylate < ethyl acrylate methyl acrylate. The effects of radiation dose, temperature, and original monomer and emulsifier concentrations were studied with respect to the following factors properties of polymer dispersions, number and size of polymer particles, viscometrically determined molecular weights, monomer-water ratio, and kinetic constants. 

Yan et al. [52] explored the use of IPN techniques to produce a composite vinyl-acrylic latex. The first-formed polymer was produced using VAc and divinyl benzene (DVB), while the second formed polymer constituted a BA/DVB copolymer. In both cases the DVB was added at 0.4 wt%. They compared this product with another product, a bidirectional interpenetrating netwodc (BIPN) in which VAc was again polymerized over the first IPN. They noted that the compatibility between the phases was more pronounced in the BIPN than in the IPN as determined using dynamic mechanical measurements and C nuclear magnetic resonance spectroscopy. The concept of polymer miscibility has also been used to produce composite latex particles and thus modify the pafamance properties of VAc latexes. Bott et al. [53] describe a process whereby they bloid VAc/ethylene (VAc/E) copolymers with copolymers of acrylic acid or maleic anhydride and determine windows of miscibility. Apparently an ethyl acrylate or BA copolymer with 10-25 wt% AA is compatible with a VAc/E copolymer of 5-30 wt% ethylene. The information obtained from this woik was then used to form blends of latex polymers by polymerizing suitable mixtures of monomers into preformed VAc/E copolymers. The products are said to be useful for coating adhesives and caulks. 

Rindfleisch et al. [6] determined the solubility of different poly(acrylates) in CO2 (Fig. 2.4). With decreasing length of monomer units, from octadecyl acrylate to ethyl acrylate, their polarity increases. The dipole-quadrupole interactions between these groups and CO2 promote the mutual solubility, which leads to a... 

PGC has been used to determine the composition (Le., monomer ratios) of a wide range of copolymers including ethylene-propylene [90, 91], natnral rubber and styrene butadiene rubbers [92, 93], styrene-divinyl benzene [94], polyhexafluoropropylene-vinylidene fluoride [95], acrylic and methacrylic acid [96], PE-ethyl acrylate and PE-vinyl acetate [97], and MMA-ethyl acrylate copolymers [98]. 

The more volatile monomers (vinyl chloride, butadiene, and acrylonitrile) are determined by dissolution of the polymer. The injections of water into polymer solutions containing styrene and 2-ethyl hexyl acrylate monomers prior to head-space analysis greatly enhanced the detection capability for these monomers. 

Since the first preparation of stereoregular poly(methyl methacrylate) by Fox et al. and Miller et al. in 1958, a large number of papers have been published on the steieospecific polymerization of methyl methacrylate, while the NMR technique for the determination of microstructure developed by Bovey and Tiers and Nishioka et al. enabled us to accumulate the extensive information on this polymerization. Mostly anionic initiators have been used for the pdymerization. A review on the polymerization by lithium compounds was presented by Bywater In a recent review by Pino and Suter were discussed some of the factors which can influence the stereoregulation in the polymerization of vinyl monomers including a-substituted acrylate. A variety of magnesium and aluminum compounds can be utilized as stereospecific initiators. Besides methyl methacrylate, not only methacrylates with various ester groups, but also a-substituted acrylates, such as a-ethyl- or o-phenyl-acrylate, were also subjected to the stereospecific polymerization by anionic initiator. The stereospecificity in the copolymerization between the monomers described above is also a matter of interest. 

If a one-dimensional spectrum does not provide sufficient information to determine the polymer structure, two-dimensional techniques, such as INADEQUATE, may be employed (see Sec. II.E.4). For example, this experiment was used to measure the sizes of the cyclic materials, poly(ethyl a-[(allyloxy)methyl] acrylate) and poly(allyl a-[hydroxymethyl] acrylate) carbon-carbon connectivities could be traced around the rings [100]. Such advanced techniques are particularly useful for characterizing the regiore-gularity of some polymers. Certain monomers, such as vinyl fluoride, can add to a growing chain in either a head-to-tail, ... 

It is possible to determine vinyl chloride and butadiene at the 0.05 ppm level and acrylonitrile down to 0.5 ppm. The injection of water in the case of styrene and 2-ethylhexyl acrylate makes it possible to determine styrene down to 1 ppm and 2-ethyl hexyl acrylate at 5 ppm. The relative precision and error in the determination of these monomers near the quantitation limit is less than 7%. 

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