Abstract
Phase behavior, miscibility, or immiscibility in blends of two polymers with carbonyl groups, PVAc and homologous polyesters of different CH 2/CO ratios, were examined using DSC, OM and SEM. Polyesters used in this study included PES, PEA, PPA, and PBA. PVAc/polyester blends were found to be immiscible with distinctly a two-phase morphology when the polyesters' structural CH2/CO ratios are lower than 3 or higher than 4; whereas miscibility is seen in three blend systems: PVAc/PEA (CH2/CO = 3.0), PVAc/PPA (CH2/CO = 3.5), and PVAc/PBA (CH2/ CO = 4.0). Asymmetry in the Tg-composition relationships is seen in all three miscible blend systems. Such non-specific, weak and asymmetrical interactions, though sufficient to maintain borderline miscibility in the blends, may be partially responsible for leading to the noted asymmetry in the T g-composition relation of the blends. Mechanism and origin of this phenomenon of asymmetry in Tg-composition relationships in some blends may be still puzzling. Strictly speaking, the non-equilibrium phenomenon of glass transition may not be ideal for evaluating the strength of intermolecular interactions in blends. Future perfection on more suitable approaches may yet be needed.
Original language | English |
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Pages (from-to) | 1404-1413 |
Number of pages | 10 |
Journal | Macromolecular Chemistry and Physics |
Volume | 207 |
Issue number | 15 |
DOIs | |
Publication status | Published - 2006 Aug 2 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry