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Hydroxyl-functionalized homo-and co-polyimides 6FDA-(DAM) x -(HAB) y (with x:y molar ratio of 1:0; 2:1; 1:1; 1:2) and two metal organic frameworks (MOFs), MIL-53(Al) and NH 2 -MIL-53(Al) were synthesized for preparation of mixed matrix membranes (MMMs). The MOF loadings were varied over the range of 10-20 wt% for NH 2 -MIL-53(Al) and 10-15 wt% for MIL-53(Al). The incorporation of hydroxyl groups into the polyimide backbone is expected to improve the interfacial interaction between the polymer matrix and fillers, consequently, enhancing gas separation performance of MMMs. A big increase in glass transition temperature (T g ) for MMMs confirmed the polymer chain rigidification, which was caused by a strong interaction between the hydroxyl groups in the copolyimides and the amine groups in NH 2 -MIL-53(Al). Additionally, SEM results showed that the hydroxyl groups facilitated the particle dispersion in the MMMs, either was NH 2 -MIL-53(Al) or MIL-53 used as filler. Gas separation performances of MMMs were characterized by both CO 2 /CH 4 pure gas and binary permeation measurements at 35 °C and 150 psi. The incorporation of NH 2 -MIL-53(Al) in the hydroxyl-copolyimides was found to significantly improved the CO 2 /CH 4 separation factor while maintaining CO 2 permeability of the MMMs as high as those of the neat corresponding copolyimides, therefore greatly enhancing the MMM separation performance. For example, the MMM prepared from 6FDA-DAM-HAB (1:1) copolyimide and 10 wt% NH 2 -MIL-53(Al) showed a permeability/selectivity behavior approaching the 2008 Roberson's upper bound making it attractive for practical usage. The significant improvement in 2 CO 2 /CH 4 separation factor observed for the MMMs made of the hydroxyl-copolyimides and the aminefunctionalized MOFs was due to (i) the enhanced polymer-filler compatibility originated from a mutual interaction between the polymer-functional moieties and the amine-functionalized MOF surface yielding defect-free MMMs and (ii) the high CO 2 /CH 4 selective adsorption in the NH 2 -MIL-53(Al) framework.

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Background:Today, polyurethane foams can be found in various commercial products such as bedding, home furniture, automotive interiors and even construction materials. From a chemical point of view, polyurethane foams are made from a chemical reaction between a polyol (molecules with more than one hydroxyl group) and a diisocyanate in the presence of a blowing agent.Objective:Because of their highly stable bonds, polyurethane foams are considered as nondegradable leading to some environmental impact. To address this concern different bio-based fillers have been used to create "greener" polyurethane materials. This review presents an overview of different bio-based fillers and containing natural polyols for polyurethane foams formulation with respect to their natural properties, sizes, geometries and contents.Method:A wide range of bio-based fillers derived from wood and non-wood sources are summarized based on their physico-mechanical properties. Then, possible applications are presented and future trends are discussed for the research and development of these complex (multiphase systems) materials (polymer composite foams).Conclusion:Beside traditional polyurethane foams applications including automotive, building, home furniture and package, bio-based filler addition could bring new feature and widen their applications such as shape memory and medication, as well as oil absorbent.