Hydrophobic/hydrophilic P(VDF‐TrFE)/PHEA polymer blend membranes

Abstract

WileyTamaño-Machiavello, MN.; Bracke, B.; Costa, C.; Lanceros-Mendez, S.; Sabater I Serra, R.; Gómez Ribelles, JL. (2016) ABSTRACTPolymer blend membranes have been obtained consisting of a hydrophilic and a hydrophobic polymers distributed in co-continuous phases. In order to obtain stable membranes in aqueous environments, the hydrophilic phase is formed by a poly(hydrohyethyl acrylate), PHEA, network while the hydrophobic phase is formed by poly(vinylidene fluoride-co-trifluoroethylene) P(VDF-TrFE). To obtain the composites, in a first stage, P(VDF-TrFE) is blended with poly(ethylene oxyde) (PEO), the latter used as sacrificial porogen. P(VDF-TrFE)/PEO blend membranes were prepared by solvent casting at 70°followed by cooling to room temperature. Then PEO is removed from the membrane by immersion in water obtaining a P(VDF-TrFE) porous membrane. After removing of the PEO polymer, a P(VDF-TrFE) membrane results in which pores are collapsed. Nevertheless the pores reopen when a mixture of hydroxethyl acrylate (HEA) monomer, ethyleneglycol dimethacrylate (as crosslinker) and ethanol (as diluent) is absorbed in the membrane and subsequent polymerization yields hybrid hydrophilic/hydrophobic membranes with controlled porosity. The membranes are thus suitable for lithium-ion battery separator membranes and/or biostable supports for cell culture in biomedical applications.

Ferroelectric and relaxor ferroelectric activities of the P(VDF‐TrFE) and its blends synthesized by (SiMe3)3SiHhydrogenation process

“…Polyvinylidene fluoride (PVDF), as a flexible dielectric polymer possessing excellent ferroelectric, piezoelectric and pyroelectric properties, has been widely investigated for their potential applications in sensors, actuators, generators, and other energy conversion apparatus. 1,2 As is known, the ferroelectricity of PVDF is closely related to the special conformation of overlapped molecular chains -CH 2 -CF 2and the arranging of molecular chains. Commonly, the molecular chain of PVDF can form into different conformations, that is, four crystalline phases of α, β, γ, and δ, and among them β-phase molecular chain has the same intracellular dipole arrangement direction and is in all-trans conformation, which has been proved responsible to its good ferroelectric and piezoelectric properties.…”

Blends of Poly(vinyl Pyridine)s and Dihydric Phenols: Thermal and Infrared Spectroscopic Studies. Part V

“…In the case of polymer-polymer blends, the obtaining of materials with enhanced properties is supported by the fundamental characterization of the intermolecular interactions involving a series of different functional groups, namely: methacrylic acid and ether groups [12], 4-vinylphenol and 2-ethoxyethyl methacrylate [13], itaconamic acids and 2-vinylpyridine [14], aryl esters [15], lactam group [16], lactide and styrene [17], vinyl methyl ether and methyl methacrylate [18], ethylene oxide and vinyl alcohol [19], aniline and amide groups [20] and alkylstyrenes and isoprene [21], among others. In this way it has been possible to find many applications involving polymer-polymer blends [22][23][24][25] and re-using preexisting polymeric materials [6,25,[26][27][28]. Biodegradable polymer blends have also attracted increasing attention in recent years [24,29].…”

Crystallization kinetics of poly(ethylene oxide) confined in semicrystalline poly(vinylidene) fluoride

“…In our recent article, poly(vinylidene fluoride)/poly(ethylene oxide) (PVDF/PEO) crystalline–crystalline blends were prepared with a procedure that confines PEO chains between PVDF crystalline entities. A similar procedure was used previously to confine PEO in poly(vinylidene fluoride‐ co ‐trifluoroethylene) copolymers . Briefly, a solution of both components in dimethyl formamide (DMF) was homogenized and solvent allowed to slowly evaporate at 70 °C.…”

“…The two‐step crystallization procedure from the solution, proposed in refs. , allowed obtaining a very homogeneous dispersion of PEO in a matrix formed by the piezoelectric polymer. The understanding of the physical properties of the water absorbing PEO rich phase of the blend is essential for the application of these blends in areas of increasing interest such as sensors and actuators, filtration membranes, and battery separator membranes .…”

“…A similar procedure was used previously to confine PEO in poly(vinylidene fluoride-co-trifluoroethylene) copolymers. [21][22][23][24][25] Briefly, a solution of both components in dimethyl formamide (DMF) was homogenized and solvent allowed to slowly evaporate at 70 8C. At this temperature, PVDF crystallizes from the solution while PEO chains are in the liquid state up to the end of the drying process since PEO melting temperature is below 70 8C.…”