Ethylene-co-methyl acrylate

Bhattacharya AK et al. (1995) Studies on miscibility of blends of poly(ethylene-co-methyl acrylate) and poly(dimethyl siloxane) rubber by melt rheology. J Appl Poly Sci 55( 13) 1747—1755... 

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. 

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. 

FIGURE6.1.11. Pyrogram of poly(ethylene-co-methyl acrylate) 21.5%wt. methyl acrylate (upper trace) (M - 79,000) and of high-density polyethylene (lower trace). Pyrolysis done on 0.4 mg material at 60(f C in He, with the separation on a Carbowax type column. 

TABLE 6.1.7. Identification of peaks in the pyrogram of poly(ethylene-co-methyl acrylate) 21.5% wt. methyl acrylate, = 79,000, as shown in Figure 6.1.11 upper trace. 

The peaks from the pyrogram of poly(ethylene-co-methyl acrylate) resulting from the ... 

Pyrolysis for a sample of the same type of copolymer but with a lower proportion of methyl acrylate also was performed. The sample contained 6.5% MAc and the pyrolysis and the separation of pyrolysate were performed in the same conditions as for poly(ethylene-co-methyl acrylate) 21.5% Mac. A time window between 30 min. and 50 min. from the pyrograms of the two samples (with 6.5% MAc and with 21.5% MAc) is shown in Figure 6.1.12. 

Figure 3.27 Cloud point behavior of the poly(ethylene-co-methyl acrylate) (69 mol% ethylene and 31 mol% methyl acrylate) in ethane, propane, ethylene, and propylene. The copolymer concentration is fixed at 5wt% and the weight-average molecular weight of the copolymer is 99,000 with a molecular weight polydispersity of 3.0. (Hasch et al., 1993.)...

Table 3.4 Properties of the Solvents Used in a Poly(Ethylene-co-Methyl Acrylate)-Hydrocarbon Study. The symbols for polarizability, dipole moment, and quadrupole moment are a, fi, and Q, respectively...

Figure 5.11 Ternary phase diagram for the poly(ethylene-co-methyl acrylate) (69 mol%/31 mol%)-propane-acetone system at 145°C (Meilchen, 1991). The symbols are experimental data. The dashed and solid lines are phase boundaries and tie lines respectively, using the Sanchez-Lacombe EOS with /c,y and rj,y set equal to zero for the EMAewsi-acetone pair, kij = 0.030 and 7]ij = 0.000 for the propane-acetone pair, and kij = 0.023 and r),j = -0.002 for the EMAe i-propane pair. The weight average and number average molecular weights of EMAeg/ai are 58,900 and 31,000, respectively.

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... 

Table 9.6 Physical Properties (Reid, Prausnitz, and Poling, 1987) of the Five Solvents Used to Fractionate Poly(ethylene-co-methyl acrylate) copolymers. The Polarizability is a (Miller and Savchik, 1979), and the Dipole Moment is ft...

Hasch, B. M., M. A. Meilchen, S.-H. Lee, and M. A. McHugh. 1992. High pressure phase behavior of mixtures of poly(ethylene-co-methyl acrylate) with low molecular weight hydrocarbons. J. Polym. Sci. Polym. Phys. Ed., 30 1365-1373. 

Polymer (B) poly (ethylene-co-methyl acrylate) 2004BEC... 

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