Dilute Solution Properties of Random Acrylonitrile/ Methyl Acrylate Copolymer

Abstract

ABSTRACT:A copolymer of acrylonitrile (AN) and methyl acrylate (MA) was prepared by use of a redox catalyst and was separated into 16 fractions by successive solution fractionation, using dimethyl sulfoxide as the solvent and toluene as the precipitant. Except for the first few, all fractions had essentially the same composition: 92 ± 0.5 weight percent in AN. Viscosity, light scattering and osmotic pressure were measured for these fractions in dimethylformamide (DMF), an ethylene carbonate (EC)Iwater mixture containing 82.5 wt% EC, and aqueous nitric acid of various compositions. This ECiwater mixture at 25°C and 51 wt% aqueous nitric acid at 25°C were found to be Flory's theta solvents for the ANIMA copolymer with 92 wt% AN. The MarkHouwink-Sakurada equations for this polymer were [I] 50 in 51 wt% aqueous nitric acid, all at 25oc. The molecular weight dependence of the radius of gyration (S 2 )!1 2 in DMF at 25°C was represented by (S 2 )!1 2 Icm=2.13 x 10-9 M';,; 58 . Flory's viscosity parameter <P was found to be 2.5 x 10 23 in DMF at 25oC and 2.9 x 10 23 in the ECjwater mixture at 25°C. The unperturbed chain dimensions A determined by both thermodynamic and hydrodynamic methods were 0.93 in DMF, 0.86 in the EC/ water mixture, and 1.11 in 55 wt% aqueous nitric acid, all at 25°C, in units of 10-8 em.

Understanding the interactions in acrylic copolymer/1‐butyl‐3‐methylimidazolium chloride from solution rheology

“…It is interesting to compare the intrinsic viscosities of PAN/[BMIM]Cl solution with the other PAN copolymers, poly(AN‐co‐MA) and poly(AN‐co‐AM) in [BMIM]Cl. The incorporation of MA and AM as comonomers increases the [ η ] values indicating that the copolymer chains are more expanded than homo‐polymer chains in [BMIM]Cl . Additionally, a trend seen in Table is that the intrinsic viscosities of poly(AN‐co‐AM) in [BMIM]Cl significantly increase with increasing content of comonomer AM.…”

“…The reaction was stopped after 3 h. The precipitated copolymer was filtered several times with deionized water until the filtrate was determined pH = 7 using pH paper discarded after measurement, and then washed with ethanol. The random copolymers could be obtained from AN and the second monomer . All the copolymers were dried under vacuum at 60 °C for at least 10 h.…”

“…The random copolymers could be obtained from AN and the second monomer. [32,33] All the copolymers were dried under vacuum at 60 C for at least 10 h.…”

“…The incorporation of MA and AM as comonomers increases the [] values indicating that the copolymer chains are more expanded than homo-polymer chains in [BMIM]Cl. [33,39] Additionally, a trend seen in Table 1 is that the intrinsic viscosities of poly(AN-co-AM) in [BMIM]Cl significantly increase with increasing content of comonomer AM. This indicates that the solvent thermodynamic quality of [BMIM]Cl can be definitely improved by incorporation of the comonomers into the PAN backbone, especially for monomer AM.…”