A study on preferential solvation on styrene-methyl methacrylate copolymers of varying architecture and composition by conventional and density gradient sedimentation equilibrium methods
✍ Scribed by Nakazawa, Atsushi ;Donkai, Nobuo ;Kotaka, Tadao ;Inagaki, Hiroshi
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1977
- Tongue
- English
- Weight
- 527 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0007-1641
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✦ Synopsis
Abstract
Preferential solvation in quasiternary systems composed of p‐xylene (pXY), 1,2‐dibromo‐1, 1‐difluoroethane (DBFE) and styrene (ST)‐methyl methacrylate (MMA) copolymers of varying architecture and composition was studied by two ultracentrifugation methods: sedimentation equilibrium in a density gradient and conventional sedimentation equilibrium. The preferential solvation parameters were estimated for the systems containing alternating, statistical and block copolymers as well as polymethyl methacrylate (PMMA) and polystyrene (PST). Virtually no solvation was observed by PST, while significant solvation of DBFE to MMA units took place. For alternating and statistical copolymers the solvation parameter is approximately the composition average of those of PST and PMMA, although a slight but distinct difference between those of the alternating and statistical copolymers was observed. However, in block copolymers of either PST‐PMMA or PMMA‐PST‐PMMA type of high PST content, it appears that the solvation of DBFE to PMMA‐blocks is suppressed by the presence of PST‐blocks.