Experimental studies on static laser light scattering of synthetized poly (acrylonitrile-co- methyl methacrylate) copolymer at room temperature

Abstract

The static light scattering technique (SLS) is one of the absolute techniques that are used for the determination of weight average molecular weight (M¯w) of polymer solutions. In this technique, the scattered laser light intensity is measured at different scattering angles for various polymer concentrations to construct the Zimm plot which can be used for a simultaneous determination of M¯w, radius of gyration (Rg), and the second virial coefficient (A2). In this study, Poly (acrylonitrile–co-methyl methacrylate) copolymer, P(AN-co-MAA), was synthesized from acrylonitrile (AN) and methyl methacrylate (MMA) monomers using the precipitation polymerization method. Polymerization was carried out using potassium persulfate (K2S2O8) as an initiator with monomer ratios 1:1 of AN: MMA. The co-polymerization process was verified by Fourier transform infrared spectroscopy (FTIR). Refractive index (n) and refractive index increment (dn/dc) of the P(AN-co-MAA) copolymer solutions were determined experimentally using a Mach-Zehnder interferometer excited by a low power He-Ne laser in order to calculate the M¯w, Rg, and A2 of the synthetized copolymer using the static laser light scattering technique. M¯w, Rg, and A2 were found to be 9.7 × 105 g/mol, 345 nm, and 5 × 10−7 mol. cm3/g2.