The strategies of molecular architecture and modification of polyimide-based membranes for CO2 removal from natural gas—A review

Over the past two decades, membrane processes have gained a lot of attention for the separation of gases. They have been found to be very suitable for wide scale applications owing to their reasonable cost, good selectivity and easily engineered modules. This critical review primarily focuses on the various aspects of membrane processes related to the separation of biogas, more in specific CO2 and H2S removal from CH4 and H2 streams. Considering the limitations of inorganic materials for membranes, the present review will only focus on work done with polymeric materials. An overview on the performance of commercial membranes and lab-made membranes highlighting the problems associated with their applications will be given first. The development studies carried out to enhance the performance of membranes for gas separation will be discussed in the subsequent section. This review has been broadly divided into three sections (i) performance of commercial polymeric membranes (ii) performance of lab-made polymeric membranes and (iii) performance of mixed matrix membranes (MMMs) for gas separations. It will include structural modifications at polymer level, polymer blending, as well as synthesis of mixed matrix membranes, for which addition of silane-coupling agents and selection of suitable fillers will receive special attention. Apart from an overview of the different membrane materials, the study will also highlight the effects of different operating conditions that eventually decide the performance and longevity of membrane applications in gas separations. The discussion will be largely restricted to the studies carried out on polyimide (PI), cellulose acetate (CA), polysulfone (PSf) and polydimethyl siloxane (PDMS) membranes, as these membrane materials have been most widely used for commercial applications. Finally, the most important strategies that would ensure new commercial applications will be discussed (156 references).

Membrane-based technologies for biogas separations

https://cyberleninka.org/article/n/457561.pdf

Compatibilization in bio-based and biodegradable polymer blends

Conventional polyolefins new polyolefins stereoregular polar thermoplastics syndiotactic polystyrene unplasticized polyvinyl chloride (uPVC) - fracture and fatigue properties acrylonitrile-butadiene-styrene (ABS) polymers styrene copolymers polyacrylonitrile polyacrylates polyacrylamides vinyl acetate polymers vinyl alcohol polymers synthetic water-soluble polymers cellulose plastics thermoplastic elastomers thermplastic polyurethanes polyester-based thermplastic elastomers polybutylene terephthalate compatibilized thermoplastic blends toughening of thermoplastics polyacetal polyether polyarylates polycarbonates polyamides polyimides polybenzimidazoles aromatic polyhydrazides and their corresponding polyoxadiazoles polyphenylquinoxalines polyphenylene sulfide polyphenylene vinylene conducting thermoplastics conducting thermoplastics composites poly(aryl ether sulfone)s poly(aryl ether ketone)s poly(aryl ether ketones-co-sulfones) poly(aryl ether ketone amide)s polytetrafluoroethylene liquid crystalline polymers advanced thermoplastics composites.

Handbook of Thermoplastics

Biodegradable aliphatic polyesters (BAPs), synthesized from diols and dicarboxylic acids, and organophilic montmorillonite (OMMT) were intercalated by a solvent-casting method using chloroform as a cosolvent to produce nanocomposite (BAP/OMMT). The d spacings of both BAP and BAP/OMMT were examined by X-ray diffraction analysis, and the microstructure of BAP/OMMT was examined by transmission electron microscopy. Melting temperature changes and residuals were measured by thermal gravimetric analysis. Tensile strength and elongation were also examined with a universal testing machine. Increases in both the thermal stability and the mechanical strength of BAP/OMMT were observed for several different OMMT loadings. The rheological properties of the BAP/OMMTs were also examined with a rotational rheometer having a parallel-plate geometry. The shear viscosity at low shear rate exhibited a Newtonian plateau even at high loading and showed a higher degree of shear thinning at higher shear rate. Both the Newtonian ...

Synthetic Biodegradable Aliphatic Polyester/Montmorillonite Nanocomposites

Micron-sized monodisperse crosslinked polystyrene (PS) beads have been prepared by a multistage emulsion polymerization using styrene monomer, divinylbenzene crosslinking agent, and potassium persulfate initiator in the absence of emulsifier. In the first stage of the reaction, the lower the reaction temperature, the larger the bead size obtained. In the later stages of the reaction, the particle size is increased with the initiator concentration and monomer content. Particle nucleation of the preexisting polymer seed of 0.7–0.8 μm in diameter is prepared at 60°C, then the monodisperse crosslinked PS beads > 2 μm are synthesized up to the third stage of the reaction. As the particle size grows, the number of free radicals in the growing particles increases, and the conversion of the next stage is continuously increased. The reaction mechanism is suggested that the continuous polymerization be conducted due to the diffusion of monomer into the preexisting particles to induce spherical beads in the later stages of the reaction. Otherwise, phase separation or the formation of protrusion by the capture of free radicals will be taking place. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2259–2269, 1999

Size control of polystyrene beads by multistage seeded emulsion polymerization

Miscibility of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(vinyl chloride) blends

Phase morphology and mechanical properties of the blends of Nylon 6 with scrap poly(vinyl butyral) (PVB) film and poly(styrene-block-(ethylene-co-butene)- block-styrene) (SEBS) have been investigated. Scanning electron microscopic photo- graphs revealed that the spherical PVB particles are finely and uniformly dispersed in the Nylon 6 matrix without changing the shape of the particles. The average particle sizes in all over the blend compositions for Nylon 6/PVB were slightly increased with PVB content, but the dispersed phase is tightly adhered to the matrix phase, with PVB content in the range of 20-35 wt % PVB. Elongation at break and notched Izod impact strength of all the blends were enhanced, which implies good interfacial adhesion. The rubberlike PVB film adhering to the Nylon 6 phase is suggested to give an improved impact strength and toughness. In particular, the optimum PVB content for the best impact strength is found to be in the vicinity of 20-35 wt %, and this composition exhibits better moisture resistance than the other blend compositions. All of the blends up to 35 wt % PVB show higher mechanical properties than those of Nylon 6 blended with conventional impact modifier SEBS. Thus, plasticized PVB film, which is recycled from the process of automobile safety glasses, is applicable as an impact modifier or a toughening agent of Nylon 6. q 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 1531- 1540, 1998

Morphology and Mechanical Properties of Nylon 6 Toughened with Waste Poly(vinyl butyral) Film

Monodisperse crosslinked polystyrene (PS) beads were prepared by a reaction of semibatch emulsion polymerization with styrene monomer, divinylbenzene (DVB) crosslinking agent, and potassium persulfate (K2S2O8) initiator in the absence of emulsifier. The glass transition temperature (Tg) and the mean diameter of the beads were increased from 100 to 135°C and from 402 to 532 nm, respectively, for an incorporation of 2–10 mol % DVB. Crosslinking density was also linearly increased with DVB content. Scanning electron microscopy (SEM) photographs of styrene–butadiene rubber (SBR) composite filled with various contents of PS beads revealed that PS beads are relatively well dispersed without changing the spherical shape of the beads in all ranges of compositions. In stress–strain analysis, elongation at break and tensile strength of SBR composite were increased with the bead content. Applicability of the PS beads as a filler in SBR matrix is tested by plotting Mooney–Rivlin or Guth–Smallwood equations. However, mechanical properties of the composite with the beads were not so excellent as those of the composite with carbon black. Crosslinked PS beads are still tentative as a white color reinforcing filler on the SBR matrix. © 1995 John Wiley & Sons, Inc.

Characterization of crosslinked polystyrene beads and their composite in SBR matrix

Mechanical and Morphological Phase Behavior in Miscible Polyethersulfone and Polyimide Blends

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Yoon-Jong Cha

Papers

Size control of polystyrene beads by multistage seeded emulsion polymerization

Miscibility of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(vinyl chloride) blends

Morphology and Mechanical Properties of Nylon 6 Toughened with Waste Poly(vinyl butyral) Film

Characterization of crosslinked polystyrene beads and their composite in SBR matrix

Mechanical and Morphological Phase Behavior in Miscible Polyethersulfone and Polyimide Blends