Butyl acrylate solution copolymers

Acrylate and Methacrylate Polymers. Poly(ethyl acrylate) and poly(butyl acrylate) solutions and emulsions are important raw materials for pressure-sensitive adhesives. Copolymers of various esters, which give films of tailor-made hardness and which may additionally contain functional groups (carboxyl, amide, amino, methylol, hydroxyl), are used for pressure-sensitive adhesives to improve the adhesion properties or to enable the adhesive layer to be cross-hnked to a limited extent. 

By employing anionic techniques, alkyl methacrylate containing block copolymer systems have been synthesized with controlled compositions, predictable molecular weights and narrow molecular weight distributions. Subsequent hydrolysis of the ester functionality to the metal carboxylate or carboxylic acid can be achieved either by potassium superoxide or the acid catalyzed hydrolysis of t-butyl methacrylate blocks. The presence of acid and ion groups has a profound effect on the solution and bulk mechanical behavior of the derived systems. The synthesis and characterization of various substituted styrene and all-acrylic block copolymer precursors with alkyl methacrylates will be discussed. 

Product Identification was by GC/MS, NMR, and IR. Fundamental crosslinking chemistry was explored using swell measurements on simple solution copolymers and swell and tensile measurements with vinyl acetate (VAc), vinyl acetate/butyl acrylate (VAc/BA) or vinyl acetate/ethylene (VAE) emulsion copolymers. Polymer synthesis 1s described In a subsequent paper (6). Homopolymer Tg was measured by DSC on a sample polymerized In Isopropanol. Mechanistic studies were done 1n solution, usually at room temperature, with 1, 2 and the acetyl analogs 1, 2 (R =CH3). 

Butvl Acrylate (BAl Solution Copolymers. Polymerizations were run with 0.30 mmol of comonomer per calculated g of polymer solids premixed with BA Reactor Charge X g comonomer, (50-X) g of butyl acrylate, 120 g of dry toluene, 0.15 g of 2,2 -azob1s1sobutyron1tr11e (AIBN). 

In contrast to those block copolymers synthesised from styrene in bulk, those synthesised from isoprene and butyl acrylate in emulsion or solution were contaminated by only small amounts of homopolymer. Furthermore, it should be noted that Piirma et al. 74 7S) have turned to the reverse reaction order for preparing poly(styrene-b-MMA), i.e. they synthesised the prepolymer using an azo initiation and the subsequent block copolymer via a peroxide redox initiation. 

In an apparently homogeneous solution, macromonomers, possibly together with the resulting graft copolymers, may lead to some structure formation such as micelle or looser association, which may in turn change the apparent reactivities due to some specific solvation or partition of the monomers around the active sites. Such a bootstrap effect [52] maybe responsible for some complicated dependency of the apparent reactivities on the monomer concentration and composition in radical copolymerization of 29 with n-butyl acrylate [53]. 

Phase behavior studies with poly(ethylene-co-methyl acrylate), poly (ethylene-co-butyl acrylate), poly(ethylene-co-acrylic add), and poly(ethylene-co-methacrylic acid) were performed in the normal alkanes, their olefinic analogs, dimethyl ether, chlorodifluoromethane, and carbon dioxide up to 250 °C and 2,700 bar. The backbone architecture of the copolymers as well as the solvent quality greatly influences the solution behavior in supercritical fluids. The effect of cosolvent was also studied using dimethyl ether and ethanol as cosolvent in butane at varying concentrations of cosolvent, exhibiting that the cosolvent effect diminishes with increasing cosolvent concentrations. 

Block co-polymers have been synthesised in [C4Ciim][PF6] by ATRP of butylacrylate and acrylate monomer.[62] The outcome of the reaction depends significantly on the order of substrate addition. If, for example, methyl acrylate was added to a two-phase system of poly-butylacrylate and ionic liquid, the resulting copolymer has a narrow polydispersity and is essentially free of homopolymer. A markedly higher amount of homopolymer was formed when butyl acrylate was added to a solution of poly-methyl acrylate and the degree depended on the stage of the MA polymerisation. Below 70% conversion, copolymer without homopolymer was formed, while above 90% conversion, practically no co-polymer was produced. 

As a general statement, isomerizations occur much slower (around lOOtimes and more) in the film than in solution. It was already observed for azo compounds by Kamogawa et in the case of copolymers of 4-vinyl-4 -dimethylaminoazobenzene (I) with styrene and of 4-acryloylaminomethylaminoazobenzene (II) with styrene, butyl acrylate and methyl methacrylate. 

In a second article the same approach was used to synthesize a peptidic polymer containing the peptide Tritrpticin, a 13 residue antimicrobial peptide (Fig. 16) [66]. This time they initiated the polymerization of f-butyl acrylate, followed by styrene to produce a triblock copolymer, which clearly formed micelles in solution. Interestingly, the antimicrobial activity of the peptide was enhanced relative to the free peptide and the detrimental side effects normally associated with antimicrobial peptides, such as a high hemolytic activity, were reduced, highhghting the benefits of using peptide polymer hybrids in place of peptides alone. 

Acrylates 8, 14, and 17 were also copolymerized with n-hexyl methacrylate or n-butyl acrylate in emulsion reactions (sodium lauryl sulfate, K2S20a, 60°C) as were chain-extended acrylates 10, 13, 16 and 19. The copolymers of 17 and 19 were low molecular weight materials again due to easy chain transfer. The bulk copolymerization of 19 with n-hexyl methacrylate gave reasonably high molecular weights.1 Some solution copolymerizations were also carried out. Representative results are summarized in Table 2. 

The results in Table XIV were obtained by adding an aqueous zinc chloride solution to a poly (butyl acrylate) latex. After precomplexation at 30°C, the monomer mixture and the redox catalyst were added, and the polymerization was carried out at 30°C. Because of the heterogeneity of the reaction mitxure, a large amount of alternating copolymer accompanied the alternating copolymer graft copolymer. 

A copolymer of butyl acrylate and acrylic acid was synthesized so as to approximate formulations used in waterborne formulation practice without departing drastically from the acrylic acid homopolymer. When 2-methy1-2-propanol solutions of these polymers were diluted with water and then dried, the rigidity trends followed the pattern (72) shown in Figure 8 and no evidence of secondary hydration was present. Reference to the original articles will reveal that the number of carboxylate triads should be minimized in the copolymerization if one wishes to ensure that the marketed product will be water insensitive. 

Acrylate rubbers such as poly (butyl acrylate) or poly (ethyl hexylacrylate) are characterized by better aging characteristics than polydienes. Ethyl hexylacrylate and acrylonitrile were grafted onto PVC in solution by R. G. Bauer and M. S. Guillord. They observed that this graft copolymer was transparent in contrast to a mere polyblend of PVC and an AN/acrylate copolymer. 

Polymers with pendant cyclic carbonate functionality were synthesized via the free radical copolymerization of vinyl ethylene carbonate (4-ethenyl-l,3-dioxolane-2-one, VEC) with other imsaturated monomers. Both solution and emulsion free radical processes were used. In solution copolymerizations, it was found that VEC copolymerizes completely with vinyl ester monomers over a wide compositional range. Conversions of monomer to polymer are quantitative with complete incorporation of VEC into the copolymers. Cyclic carbonate functional latex polymers were prepared by the emulsion copolymerization of VEC with vinyl acetate and butyl acrylate. VEC incorporation was quantitative and did not affect the stability of the latex. When copolymerized with acrylic monomers, however, VEC is not completely incorporated into the copolymer. Sufficient levels can be incorporated to provide adequate cyclic carbonate functionality for subsequent reaction and crosslinking. The unincorporated VEC can be removed using a thin film evaporator. The Tg of VEC copolymers can be modeled over the compositional range studied using either linear or Fox models with extrapolated values of the Tg of VEC homopolymer. 

In all cases the data fit the models equally well. The data is summarized in Table VII. The plots of the data and the line of fit are in Figures 8 through 13. In the case of the solution copolymers, the extrapolated Tg values for butyl acrylate and vinyl acetate agree reasonably well with typical literature values of -54°C and 32 C, respectively [12], However, there is a wide variation in the values determined for... 

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