Light-scattering studies on polystyrenes in isorefractive poly(methyl methacrylate)–toluene “solvents”

✍ Scribed by Lin, C.-Y. ;Rosen, S. L.

• Book ID: 105334188
• Publisher: Wiley (John Wiley & Sons)
• Year: 1982
• Tongue: English
• Weight: 333 KB
• Volume: 20
• Category: Article
• ISSN: 0098-1273
• DOI: 10.1002/pol.1982.180200814

✦ Synopsis

Abstract

The rms radii of gyration 〈S^2^〉^1/2^ and second virial coefficients Γ~2~ of five monodisperse polystyrenes (M × 10^−5^ = 1.6, 2.8, 4.2, 6.6) were measured in isorefractive toluene–poly(methyl methacrylate) (M̄~v~ = 4.0 × 10^4^, 1.6 × 10^5^, and 6.3 × 10^5^) “solvents.” For a given PMMA, the concentration at which the θ condition (defined by Γ~2~ = 0) was reached was independent of PS molecular weight, but varied inversely with PMMA molecular weight (0.10, 0.056, and 0.023 g/mL, respectively). When this θ condition is reached by adding PMMA to toluene, the radii of gyration are decreased by only about 15%, much less than when it is reached by going to a poor, low‐molecular‐weight solvent. This reflects the exclusion of PMMA from the PS coils, the internal environment of which is essentially pure toluene.