Solution behavior of graft copolymers of poly(methyl methacrylate) backbone and poly(propylene oxide-b-ethylene oxide) branches: effect of structure and composition
β Scribed by Elizabete F. Lucas; Clara Marize F. Oliveira
- Publisher
- Springer
- Year
- 1995
- Tongue
- English
- Weight
- 242 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0170-0839
No coin nor oath required. For personal study only.
β¦ Synopsis
The effect of structure and composition of poly(methyl methacrylate) (PMMA) main chain and poly(propylene oxide-b-ethylene oxide) (PPO-b-PEO) graft chain on solution behavior was evaluated, Separated samples of homopolymers were also analysed to provide comparisons. The solutions ware prepared by dissolving the sample in selective mixtures of tetrahydrofuran (THF) and hexane. The polymer solutions were submitted to viscometric measurements as function of the solvent composition. The ratio of ethylene oxide/propylene oxide (EO/PO) units determines the modification in molecular conformation of the (PPO-b-PEO) block copolymers as function of the solvent composition. The macromolecular structure is the most important factor on the graft copolymers behavior. The structure in which ethylene oxide is linked to the main chain provides higher interaction between graft copolymers and solvent (THF/hexane).
π SIMILAR VOLUMES
Phase behavior of aqueous systems containing block copolymers of poly(ethylene oxide (PEO) and poly(propylene oxide) (PPO) was evaluated by building up temperature-concentration phase diagrams. We have studied bifunctional triblock copolymers (HO-PEO-PPO-PEO-OH) and monofunctional diblock copolymers
Poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA) blends were prepared by casting from either chloroform or benzene solvents. After casting from solvents, all samples used in this study were preheated to 100Β°C and held for 10 min. Then, the solvent effect on the crystallization behavior an