| Pervaporation (PV) technique, as a new separation techniqure, is highly efficient, economical, safe, and ecofriendly. In recent twenty years, organophilic pervaporation has received considerable attention in the fields including environment protection, recycle of chemical product and extraction of important chemical material and exhibits good performance. However, pervaporation performance of present membrane for hydrophilic organics is not good. Developing and studying novel polymer, especially organic-inorganic hybrid polymer, as pervaporation membrane material is an important way to improve the performance. Phosphazene polymer is a new type of inorganic/organic and organophilic polymer which is as important as the silicon polymer. Phosphazene polymer can be classified as linear polyphosphazene based polymer and cyclophosphazene polymer. Linear polyphosphazene has good tailoring property of chemical structure, good flexibility of main chain, generally good membrane forming ability and good organophilic performance. Hence, linear polyphosphazene is an excellent pervaporation membrane material. Crosslinked Cyclophophazene polymer can be an alternative organophilic filler of membrane to improve performance. Thereby, phosphazene based polymer can be applied in different aspects of organophilic pervaporation membrane due to its low cost, ability of morphology control and good affinity to general solvents. This study is scientific important and has great industrial value.A model linear polyphosphazene: ethoxy, allylphenoxy and phenoxy substituting polyphosphazene membrane was prepared. Nylon microporous membrane was used as the support membrane of polyphosphazene membrane. Toluene was used as solvent of polymer and water was used to occupy the pore of support membrane. The formed composite membrane exhibited good mechanical stability. The effect of oxygen, initiator, crosslinking temperature and time on sorption and swelling behavior of crosslinked polyme was studied. The crosslinking condition was optimized. Experiments further show that crosslinking can improve separation factor of membrane. The improvement for acetone-water and THF-water is obvious, respectively from 19.7 to 24.5 and from 22.5 to 30.3. Based on the study, detailed cross-linking mechanisms were proposedThe ethoxy, trifluoethoxy and octafluoro-1-Pentanoxy containing organophilic polyphosphazenes were designed and prepared. By comparing the pervaporation properties, the effect of properties of groups, including hydrophobicity, group length and rigidity on the final separation performance was studied in detail. Sorption experiments showed that trifluoethoxy substituting polyphosphazene membrane had the largest sorption for ethanol and octafluoro-1-Pentanoxy substituting polyphosphazene membrane had the lowest sorption for water. The sorption behaviors of the three membranes were explained by solubility parameters well. The separation performance of trifluoethoxy substituting polyphosphazene membrane is the best due to its highest ethanol sorption and diffusion selectivity. The highest separation factor and permeation flux are respectively 6.1 and 260 g·m-2·h-1 for 10% ethanol aqueous solution at 40℃which are little better than general siloxane rubbery membrane. The sorption selectivity of octafluoro-1-Pentanoxy substituting polyphosphazene membrane is the best but its diffusion selectivity is poor, leading to reduction of whole separation factor.A series of organophilic phosphazene heteropolymers (NP (OC6H4C3H5)x(OC6H5)y(OCH2CF3)z)n with different content of OCH2CF3 group were prepared. The pervaporation performance of as-prepared membranes for removal of tetrahydrofuran, acetone and ethanol was reported to study the effect of OCH2CF3 content on pervaporation performance. Pervaporation and swelling experiments showed that the incorporation of -OCH2CF3 group greatly enhances the sorption toward THF and acetone, resulting in higher selectivity comparing with polydimethylsiloxane membrane. The highest separation factors for 5% ethanol, acetone and THF aqueous solutions at 40℃are respectively 7.9, 24.9 and 30.2. Pervaporation performance was optimized by tailoring the content of OCH2CF3 group. The swelling degrees of polymers and solubility parameter analysis explain the results well. The effect of feed VOC composition, temperature and crosslinking on pervaporation results were discussed.Organophilic polyphosphazene nanotube was incorporated into polydimethylsiloxane forming nanocomposite membranes. SEM showed that polyphosphazene nanotube was uniformly dispersed in polydimethylsiloxane. Sorption experiments indicated that the nanocomposite membranes had higher ethanol affinity compared to the pure-polymer membrane. The nanocomposite membranes were demonstrated with greatly higher separation factor for water-ethanol mixture compared with polymer membranes. The highest separation factor achieves 10 and the highest permeation flux is twice that of polydimethylsiloxane which is 478 g·m-2·h-1. As nanotube content increasing, selectivity increased at first and kept almost the same. Permeation flux increased at first to a maximum value and after that decreased slightly. Incorporation of short diameter nanotube caused better pervaporation. The effects of temperature and feed solution concentration on pervaporation properties were also investigated. The improvement of separation performance is owing to good affinity to ethanol and hydrophobic property of polyphosphazene nanotube which is well explained by solubility parameter analysis. This result exhibits the advantage of polyphosphazene nanotube in organophilic property.
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