Butyl acrylate copolymers

Under conditions of extreme acidity or alkalinity, acryhc ester polymers can be made to hydroly2e to poly(acryhc acid) or an acid salt and the corresponding alcohol. However, acryhc polymers and copolymers have a greater resistance to both acidic and alkaline hydrolysis than competitive poly(vinyl acetate) and vinyl acetate copolymers. Even poly(methyl acrylate), the most readily hydroly2ed polymer of the series, is more resistant to alkah than poly(vinyl acetate) (57). Butyl acrylate copolymers are more hydrolytically stable than ethyl acrylate copolymers (58). 

Fig. 14. Oxygen permeabiUties of vinyUdene chloride— -butyl acrylate copolymers (27). See Table 1 for unit conversion.

Scheme 6. Proposed Fates of Radicals Formed by Butyl Ester Sidechain Scavenging of Chlorine Atoms Generated During the Degradative Dehydrochlorination of Vinylidene Chloride/ Butyl Acrylate Copolymers.

From the data presented here it is clear that little stabilization is provided by the presence of pendant buytl groups of any structure despite the fact that abstractable hydrogen atoms, particularly in the case of the sec-butyl acrylate copolymer, are available. This stands in contrast to an earlier observation that the presence of aliphatic pendant groups afforded stability for vinylidene chloride copolymers. [43] It may be that the size of the pendant groups in this case is too small, i.e., that the availability of abstractable hydrogen atoms is not great. Further work will be required to resolve this issue. 

EBA (ethylene-butyl acrylate copolymer) Lotryl Atofina... 

Figure 14. Stress-strain curves for 1 1 ethyl acrylate butyl acrylate copolymers with S16MA MACROMER at 30%, 40%, and 50% MACROMER contents.

Mixtures of chemically homogeneous methyl methacrylate— n-butyl acrylate copolymers appear homogeneous optically (clear) and in torsional oscillation experiments (one damping maximum) for A MM A 10-25 mole %. There is no... 

Mixtures of chemically homogeneous methyl methacrylate-n-butyl acrylate copolymers are homogeneous for composition ranges be-... 

Handel and co-workers [11] have investigated the influence of the polymerization conditions on the molecular weight and chemical composition of styrene-butyl acrylate copolymers ... 

Figure 7.1.9 Contour plot obtained for a typical GPC-NMR on-line coupling analysis of a styrene-butyl acrylate copolymer...

Vinyl acetate-butyl acrylate copolymers (0-100% butyl acrylate) were prepared by both batch and starved semi-continuous polymerization using sodium lauryl sulfate emulsifier, potassium persulfate initiator, and sodium bicarbonate buffer. This copolymer system was selected, not only because of its industrial importance, but also because of its copolymerization reactivity ratios, which predict a critical dependence of copolymer compositional distribution on the technique of polymerization. The butyl acrylate is so much more reactive than the vinyl acetate that batch polymerization of any monomer ratio would be expected to give a butyl acrylate-rich copolymer until the butyl acrylate is exhausted and polyvinyl acetate thereafter. 

Recent investigations have shown that the behavior and interactions of surfactants in a polyvinyl acetate latex are quite different and complex compared to that in a polystyrene latex (1, 2). Surfactant adsorption at the fairly polar vinyl acetate latex surface is generally weak (3,4) and at times shows a complex adsorption isotherm (2). Earlier work (5,6) has also shown that anionic surfactants adsorb on polyvinyl acetate, then slowly penetrate into the particle leading to the formation of a poly-electroyte type solubilized polymer-surfactant complex. Such a solubilization process is generally accompanied by an increase in viscosity. The first objective of this work is to better under-stand the effects of type and structure of surfactants on the solubilization phenomena in vinyl acetate and vinyl acetate-butyl acrylate copolymer latexes. 

Emulsion Polymerization A typical recipe is give in Table I. Emulsion polymerization was carried out at 60°C under a nitrogen atmosphere using a batch process. Theoretical solids content in all the formulations was 25%, and generally the conversions were better than 98%. A polyvinyl acetate homopolymer and two poly (vinyl acetate-butyl acrylate) copolymers having VA/BA composition of 85/15 and 70/30 were prepared according to the above procedure. 

Latex thickening in the presence of penetrating type anionic surfactants such as NaLS appears to depend on polymer composition as seen in Table III. The extent of latex thickening in the presence of excess NaLS decreases with the VA content of a vinyl acetate-butyl acrylate copolymer. Polystyrene and poly acrylate copolymer latexes do not show any thickening. 

Ethylene-vinyl acetate copolymer Methyl-methacrylate-butyl acrylate copolymer... 

Inaba et al. prepared a series of model styrene/butyl acrylate copolymer latexes with glass transition temperatures at room temperature. The functional monomer 2-(3-isopropenylphenyl)-2-methylethylisocyanate (TMI) was used as monomer/crosslinking agent for further film formation. A small amount of methacrylic acid was introduced in some formulations in order to enhance the crosslinking reaction. A redox initiation system was used to reduce premature crosslinking during the polymerization [82]. 

In another development, thermal analysis of POSS-containing ABA triblock methacrylate/butyl acrylate copolymers (Fig. 4) indicated the presence of two clear glass transitions in the microphase-separated system, with strong physical aging observed in samples annealed at temperatures near the Tg of the poly(methacryl-POSS) phase [122]. 

Since the product here contains ionic and nonionic groups, it will be an anionic surfactant. Such materials, which are always formed in persulfate-initiated emulsion polymerizations, have been termed in situ surfactants. Their nature has not been studied extensively. In one study, of the polymerization of a 64 36 (w/w) methyl methacrylate butyl acrylate copolymer in the presence of a chain transfer... 

This relationship is shown in Figure 13 where Polymer 1 has a permeability 1000 times higher than that of Polymer 2. Published data have small negative deviations from this theoretical relationship. Part of the deviation can be explained by densification of the blend relative to the starting components. Random copolymers, which are forced (by covalent bonds) to imitate combinations of two materials, have permeabilities that are similar to miscible blends. However, the deviations from equation 18 tend to be positive. A series of styrene—methacrylonitrile copolymers were studied (11) and slight positive deviations were found. Figure 14 shows the oxygen permeabilities of a series of vinylidene chloride— -butyl acrylate copolymers [9011-09-0]. 

Enathene. [Quantum/USI] Ethylene n-butyl acrylate copolymer for extrusitm coatings, adhesives. 

Blends of polyamide copolymers with butyl acrylate copolymers (Durethan C, with PA being a copolymer of e-caprolactam and other monomers) can be blown into films. The recommended processing conditions are screws having L/D = 25-33 and compression ratio = 3.5-4.0, barrel feed zone at T = 225-260°C and melt temperature of T = 250-280°C. For multi-layer films, adhesion between layers can be achieved either by addition of an adhesion promoter to either of the two materials or (preferably) by co-extrusion with an adhesive layer. 

EBA ethylene butyl acrylate copolymer MW molecular weight... 

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