Methyl acrylate, copolymers with

Table 1. TLC developments of styrene-methyl acrylate copolymers with single solvents...

Urban and co-workers [82] stndied the strncture of styrene-acrylic acid copolymers using attenuated total reflection Fonrier transform infrared spectroscopy. Kandu and El Gamel [83] correlated the relative intensities of the carbonyl frequencies of the methyl acrylate units in styrene methyl acrylate copolymers with copolymer composition. The positions and shapes of the carhonyl hands in the infrared absorption spectra of the copolymers dissolved in chloroform, were shown to depend on the composition of the copolymers and upon the presence of different proportions of methyl acrylate centred triads. The results obtained by infrared spectroscopy were compared with those obtained by C-NMR. Infrared spectra may be used to yield information about both the copolymer composition and the triad sequence distribution. 

Acrylonitrile—methyl acrylate—iadene terpolymers, by themselves, or ia blends with acrylonitrile—methyl acrylate copolymers, exhibit even lower oxygen and water permeation rates than the iadene-free copolymers (110,111). Terpolymers of acrylonitrile with iadene and isobutjlenealso exhibit excellent barrier properties (112), and permeation of gas and water vapor through acrylonitrile—styrene—isobutjleneterpolymers is also low (113,114). 

Copolymers of vinyUdene chloride and methyl acrylate have been studied by x-ray techniques (75). For example, the long period (lamellar thickness) for an 8.5 wt % methyl acrylate copolymer was found to be 9.2 nm by smaH-angle x-ray scattering. The unit cell is monoclinic, with a = 0.686 and c = 1.247 nm by wide-angle x-ray scattering. 

An example of this improvement in toughness can be demonstrated by the addition of Vamac B-124, an ethylene/methyl acrylate copolymer from DuPont, to ethyl cyanoacrylate [24-26]. Three model instant adhesive formulations, a control without any polymeric additive (A), a formulation with poly(methyl methacrylate) (PMMA) (B), and a formulation with Vamac B-124 (C), are shown in Table 4. The formulation with PMMA, a thermoplastic which is added to modify viscosity, was included to determine if the addition of any polymer, not only rubbers, could improve the toughness properties of an alkyl cyanoacrylate instant adhesive. To demonstrate an improvement in toughness, the three formulations were tested for impact strength, 180° peel strength, and lapshear adhesive strength on steel specimens, before and after thermal exposure at 121°C. 

Other commercially relevant monomers have also been modeled in this study, including acrylates, styrene, and vinyl chloride.55 Symmetrical a,dienes substituted with the appropriate pendant functional group are polymerized via ADMET and utilized to model ethylene-styrene, ethylene-vinyl chloride, and ethylene-methyl acrylate copolymers. Since these models have perfect microstructure repeat units, they are a useful tool to study the effects of the functionality on the physical properties of these industrially important materials. The polymers produced have molecular weights in the range of 20,000-60,000, well within the range necessary to possess similar properties to commercial high-molecular-weight material. 

Estimate if separation occurs between coating and substrate in the case where flame-treated polypropylene film, coated with vinylidene chloride/methyl acrylate copolymer is immersed in a solution of sodium n-dodecyl sulphate (concentration 0.5%). The data of polymer, coating and liquid are the following (determined in separate... 

When the monomer ratio in a copolymer increases, the contribution to the pyrolysate also increases. However, the yield of different pyrolysis products depends on the nature of the polymer. In addition to quantitative information, as shown in Chapter 4, structural information can be obtained from pyrolysate. One example in this direction is that of a poly(ethylene-co-methyl acrylate), CAS 25103-74-6, (with butylated hydroxyethyl-benzene inhibitor). A sample with 21.5% wt. methyl acrylate (MAc), with M = 79,000 and Mn = 15,000, pyrolyzed at 600° C in He with the separation on a Carbowax column generates the upper trace of the two pyrograms shown in Figure 6.1.11. The lower trace, displayed for comparison, is that of polyethylene. The peak identification for the pyrogram of poly(ethylene-co-methyl acrylate), with 21.5% wt. methyl acrylate, shown in Figure 6.1.11 was done using mass spectral library searches only, and Is given in Table 6.1.7. 

Glycidyl methacrylate has also been grafted to polyethylene and to poly(ethylene-co-propylene) using peroxides in extruders.87 The reactive group need not be pendant. It can be part of a copolymer. Ethylene-methyl acrylate copolymers and styrene-maleic anhydride copolymers have been reacted with ammonia and with amines in extruders.88... 

McHugh and coworkers describe the fractionation of various poly(ethylene-co-methyl acrylate) copolymers using supercritical propane, propylene, 1-butene, and chlorodifluoromethane (Meilchen, Hasch, and McHugh, 1991 Pratt, Lee, and McHugh, 1993). The objective of their work was to extend the work of Krukonis and coworkers (Scholsky et al., 1987 Watkins and Krukonis, 1991) who demonstrated the ability of fractionating by chemical composition of the polymer as well as molecular weight. This concept is also described with other polymer-SCF solvent systems in the next few sections of this chapter. 

Table 9.5 lists the properties of the four poly (ethylene-co-methyl acrylate) copolymers (30,40,60,70 wt% methyl acrylate, EMA30/70, EMA40/60, EMA60/40, EMA70/30, respectively). As ethylene repeat units are replaced with methyl acrylate units the copolymer becomes very polar. The size and polarizability of a... 

The material therefore readily absorbs moisture and must be effectively dried prior to moulding, otherwise a hazy or milky appearance may result. Polyacrylonitriles have a relatively low heat distortion temperature (around 75°C), hence they have limitations for products requiring a hot fill. The material is suitable for thermoforming operations but its relatively high moisture permeation is likely to restrict ultimate usage. The presence of acrylonitrile residues also placed the material under a cloud with the FDA, but use is now accepted provided acrylonitrile monomer does not exceed 0.1 ppm. Nitrile copolymers are usually copolymerised with methyl acrylate together with small quantities of butadiene/acrylonitrile rubbers. 

Figure 25. Steady shear viscosity variation with shear rate for 15% styrene-methyl acrylate copolymer suspension in a 2 wt% PAA solution (171).

PVDC-VC with vinylidene chloride-methyl acrylate copolymer (PVDC-MeA)... 

A study of the microstructure of copolymers made use of a simple solution procedure for the copolymerization of methyl acrylate (MA) with A-vinylcarba-zole (NVK). The ratio of the feed composition ranged from (0.1429 moles of MA to 1.00 of NVK) to (7 moles of 1 of NVK)—a 49-fold range in composition. The experiments were carried out to high conversions [41]. Preparation 2-8 is based on this work. The reactivity ratios calculated from this series were approximately... 

General Description Intended primarily for packaging use, acrylonitrile-based resins are sometimes called barrier resins. Acrylonitrile-Methyl-Acrylate Copolymer (AMA) is a clear, rubber-modified acrylonitrile with excellent chemical resistance and gas barrier properties, as well as a high modulus or stiff-ness.f ]... 

CHU Chu, J.H. and Paul, D.R., Interaction energies for blends of SAN with methyl methacrylate copolymers with ethyl acrylate and n-butyl acrylate. Polymer, 40, 2687, 1999. 

Another possibility to increase the polarity of a polymer is the incorporation of polar units into the polymer backbone via the synthesis of copolymers. Fig. 2.5 shows the CO2 solubility of poly(ethylene-co-methyl acrylate)s with varying amounts of the methyl acrylate monomers in the copolymer molecules. As the methyl acrylate content increases, the favorable dipole-quadrupole interactions between the methyl acrylate units and the CO2 lead to enhanced solubility and shift the cloud point curves to lower temperatures and pressures. 

However, the influence of polar comonomer units on polymer solubihty is in general neither Hnear nor necessarily monotonic. Fig. 2.6a shows the ethylene solubility of poly(ethylene-co-methyl acrylate) copolymers for different amounts of the methyl acrylate monomer in the copolymer from 0 mol% (corresponds to LDPE) to 44 mol%. For small amounts of the methyl acrylate monomer, favorable interactions of the methyl acrylate units of the copolymer with the quadru-pole moment of the ethylene enhance the solubility of the copolymer. Here, the copolymers first show a decreasing cloud point pressure. However, upon further increase of the methyl acrylate contents (above 13 mol%), the importance of the polar intermolecular interactions between the different methyl acrylate units of the copolymer molecules becomes dominant, leading to decreasing solubility. However, for the similar system poly(ethylene-co-propyl acrylate), very different behavior is observed. Here, the solubility of the copolymer increases with in-... 

The relationships between the molecular mass and the composition of styrene-methyl acrylate copolymers prepared by radical polymerization in bulk were examined [47]. Experimental results agreed with polymerization kinetics for the low-conversion samples, where the chemical heterogeneity obtained by SEC was negligible. However, the methyl acrylate content for the... 

Commercial impact-modified acrylic resins (Table 19.15) exhibit five- to tenfold improvement in the notched Izod impact strength and the ultimate tensile elongation compared to the neat PMMA resin. These impact-modified acrylics are usually blended captively by the manufacturers of the acrylic resins. The base resin in a typical weatherable grade (Plexiglas DR, Rohm and Haas) could be a methyl methacrylate copolymer with ethylacrylate and styrene, while the rubber additive (ca. 10 %) could be an emulsion-polymerized, PMMA-grafted, cross-linked poly (n-butylacrylate) rubber of controlled particle size (<200 nm). The nonweatherable impact-modified acrylic (XT, CYRO) typically consists of a MMA/S/AN copolymer with MBS (ca. 10 %) rubber particle dispersions. 

Freeze-dried and extraction with methanol and water/acetone. Extracts eluted on fractogel chromatography (methyl acrylate copolymer in solution in aqueous ethanol 20%, HW-50 F). Elution with methanol/formic acid (9 1)... 

Ethylene-methyl acrylate copolymer (EA, E/EA) n. An elastomer vulcanizable with peroxides or diamines. It resists attack by oils and temperatures to 175°C. 

POM is nucleated with polymeric nucleating material, which comprises ethylene/ methyl acrylate copolymer. ... 

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