Comparative studies on miscibility and phase behavior of linear and star poly(2‐methyl‐2‐oxazoline) blends with poly(vinylidene fluoride)

Abstract

The comparative studies on the miscibility and phase behavior between the blends of linear and star‐shaped poly(2‐methyl‐2‐oxazoline) with poly(vinylidene fluoride) (PVDF) were carried out in this work. The linear poly(2‐methyl‐2‐oxazoline) was synthesized by the ring opening polymerization of 2‐methyl‐2‐oxazoline in the presence of methyl p‐toluenesulfonate (MeOTs) whereas the star‐shaped poly(2‐methyl‐2‐oxazoline) was synthesized with octa(3‐iodopropyl) polyhedral oligomeric silsesquioxane [(IC3H6)8Si8O12, OipPOSS] as an octafunctional initiator. The polymers with different topological structures were characterized by means of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. It is found that the star‐shaped poly(2‐methyl‐2‐oxazoline) was miscible with poly(vinylidene fluoride) (PVDF), which was evidenced by single glass‐transition temperature behavior and the equilibrium melting‐point depression. Nonetheless, the blends of linear poly(2‐methyl‐2‐oxazoline) with PVDF were phase‐separated. The difference in miscibility was ascribed to the topological effect of PMOx macromolecules on the miscibility. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 942–952, 2006

Positron annihilation lifetime spectroscopy for miscibility investigations of styrene–butadiene–styrene copolymer/polystyrene blends

“…They found that linear/star blends are more miscible than the corresponding linear/linear blends, and linear/star mixtures are less miscible than star/star blends. Shen et al found that the star poly(2‐methyl‐2‐oxazoline) (POMx) was miscible with poly(vinylidene fluoride) (PVDF), but the blends of linear POMx with PVDF were phase‐separated. In our work, star‐shaped SBS 411 has wider free volume distribution (Fig.…”

Transformations and enhanced long-range ordering of mesoporous phenolic resin templated by poly(ethylene oxide-b-ε-caprolactone) block copolymers blended with star poly(ethylene oxide)-functionalized silsesquioxane (POSS)

“…In this paper, we report the surprising enhancements in both the pore sizes and long-range order of mesoporous phenolic resins when templated by PEO-b-PCL diblock copolymers blended with star PEO octa-functionalized polyhedral oligomeric silsesquioxanes (PEO-POSS) as the homopolymer. We chose to use star PEO-POSS as the homopolymer because its degree of hydrogen bonding with phenolic resin is greater than those of linear homopolymers; 44,45 we anticipated that stronger intermolecular interactions might enhance the longrange order of the mesoporous structures. 46 With aging, we expected the cage-like POSS species to form larger silica clusters that can be also found in the walls of mesoporous silica.…”

Star poly(2‐ethyl‐2‐oxazoline)s—synthesis and thermosensitivity

“…Four‐arm star polymers with poly (2‐methyl‐2‐oxazoline) and poly(2‐ethyl‐2‐oxazoline) arms were prepared using tetrakis(bromomethyl)ethylene as the initiator 21. For the preparation of poly(2‐methyl‐2‐oxazoline) stars with well‐defined but fewer arms, either halomethylated silsesquioxane with eight initiating species in one molecule22, 23 or hexakis[p‐(bromomethyl) phenoxycyclotriphosphazene] can be used as initiators 24. Iron and ruthenium tris(bipyridine) complexes have also been employed as the macroinitiators for the polymerization of 2‐R‐2‐oxazoline monomers, where R = ethyl, methyl, phenyl or undecyl 25–28.…”