High flux PP/EVOH nanofibrous composite microfiltration membrane (P/E-NCMM) based on polypropylene (PP) (575 nm) and polyethylene-co-polyvinyl alcohol (EVOH) nanofibers (248 nm) with low operation pressure for liquid filtration was fabricated by melt blending extrusion. PP nanofibers as the scaffold played a supporting role, and EVOH nanofibers filled in the PP nanofibers network structure narrowed the pore size and improved the wettability. Taking advantages of PP and EVOH nanofibers, the nanofibrous composite membrane created fascinating features for liquid filtration. The experimental results showed that the P/E-NCMM had high average pure water flux at low operating pressure. The P/E-NCMM with 30 wt % PP nanofibers showed high water flux [450.9 L/(m² h)] even at very low feeding pressure (0.05 MPa) with above 95% retention for TiO₂ suspension. The results indicated that the P/E-NCMM prepared by this method had great potential for the application in liquid filtration. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43585.

Polyamide 6 (PA6) nanofibers were prepared by the melt blending extrusion process of PA6/cellulose acetate butyrate (CAB) immiscible polymer blends. The average diameter of obtained PA6 nanofibers was 95–190 nm which could be controlled by varying the process conditions, such as blend ratio was 10/90-40/60, shear rate was 10 and 80 s⁻¹and two different blending equipments, and the effect of adding graphene for the diameters was also discussed. In addition, and the formation mechanism of nanofibers was studied by viscoelastic analysis and collecting samples at four different sites along the extruder. The morphology of PA6 dispersed phase in CAB matrix included three stages: PA6 pellets changed into sheets or ribbons, the formation of microfibers and size reduction, the size of microfibers continued refinement to nanofibers. The morphology development of dispersed phase may be postponed by blend ratio. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42184.

In this article, polymer blends of polylactide (PLA) and co-polyester (co-PET) were prepared at various weight ratios of PLA/co-PET, such as 10/90, 20/80, 30/70, and 40/60, through a twin-screw extruder. The PLA nanofibers were fabricated by removal of the co-PET matrix in water at 80°C. The morphology development of PLA dispersed phase obtained from the three different sample connections and the die of the twin-screw extruder were investigated by Scanning Electron Microscopy (SEM). It was found that the uniformed PLA nanofibers with averaged diameters less than 500 nm were fabricated by the suitable processing parameters. The processing immiscibility and rheological behavior of PLA/co-PET blends were also studied by means of Differential Scanning Calorimeter (DSC) and Capillary Rheometer. The test of Fourier Transform Infrared spectroscopy (FTIR) demonstrated that the co-PET was removed clearly in water at 80°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2832–2838, 2013

Development of high throughput production processes for making thermoplastic nanofiber and nanofiber yarns are urgently needed. PET, PTT, and PBT nanofibers were prepared from PET/CAB, PTT/CAB, PBT/CAB immiscible polymer blends by in situ microfibrillar formation during the melt extruding process. The diameter distribution and crystallization properties of PET, PTT, and PBT nanofibers were analyzed. After removing the CAB matrix phase, the nanofibers could be collected in the forms of random or aligned nanofibers and nanofiber bundles or yarns. To understand the formation mechanism of the nanofibers, the morphology development of three different polyesters in the dispersed phase were studied with samples collected at different zones in a twin-screw extruder. The morphological development mechanism of the dispersed phases involved the formation of sheets, holes and network structures, then the size reduction and formation of nanofibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Nanofiber membranes have huge potential applications in many areas due to their unique properties. However, the thermoplastic micro/nanofiber membranes were rarely reported. In this paper, polypropylene (PP) nanofibers were prepared by melt extrusion of immiscible blends of PP, cellulose acetate butyrate (CAB), and subsequent removal of the CAB matrix. The wet-laid application was used to make PP nanofiber membranes and PP-g-MAH/nonwoven micro/nanofiber membrane. The properties of membranes including morphology, apparent density, porosity, contact-angle, pore size distribution, and water flux were characterized. The results showed that the consequent membranes were provided with optimistic porosity and pore size distribution. Moreover, they were all with high pure water fluxes, which were superior to that of PP microporous membrane. They performed an excellent separation performance of TiO₂ suspension and dyeing wastewater. The work revealed this method could be an efficient one to make thermoplastic polymer micro/nanofiber membranes, and they would have a brilliant potential application for water treatment. Copyright © 2010 John Wiley & Sons, Ltd.

Multiwalled carbon nanotubes (CNTs)/polyethylene micro-nanofibers with content ranging from 0.5 to 10 wt% of CNTs were prepared for the first time by melt extrusion of immiscible blends with cellulose acetate butyrate (CAB) and subsequent removal of CAB matrix. The morphology development of dispersed phase was studied with samples collected at different zones in a twin-screw extruder. The morphology of the CNTs in PE was found to be in forms of both individual and agglomerations. The average diameters of CNTs/PE nanofibers increased with increasing the CNTs content. The electrical conductivity of CNTs/PE nanofibers was studied and a percolation threshold of about 4 wt% was obtained. In addition, the crystalline structures of the CNTs/PE nanofibers were analyzed, indicating a decrease in the crystallinity with the addition of CNTs. The thermal properties of composite fibrils were also modified. This paper demonstrates a good approach for the preparation of CNTs/TP nanofibers by in situ microfibrillar formation. Copyright © 2011 John Wiley & Sons, Ltd.

The excellent characteristics of polymeric nanofibers with diameters less than 1 μm such as the enormous specific surface result in a dramatic increase in a variety of functional applications. In this article, polymer blends of isotactic polypropylene (iPP) and polylactide (PLA) were fabricated through a twin-screw extruder. The extrudates were prepared at various processing conditions and the iPP nanofibers were obtained by removal of the PLA matrix from the drawn samples. The influences of drawing ratio, the processing temperature, and the blend ratio of iPP/PLA on the morphology development of iPP phase were investigated by scanning electron microscopy. It was found that the uniformed iPP nanofibers with averaged diameters less than 500 nm were fabricated by the suitable processing parameters. Otherwise, the processing immiscibility and rheological behavior of iPP/PLA blends were studied by means of dynamic mechanical analysis and capillary rheometer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Nano-scale poly(butylene terephthalate) (PBT) fibers were prepared from PBT/cellulose acetate butyrate (CAB) immiscible polymer blends due to in situ microfibrillar formation during a melt extruding process. The morphological development of the dispersed phase was studied with samples collected at different zones in a twin screw extruder. It was found that the holistic developmental trends of PBT dispersed phase were nearly the same. Fibers began to form even under the shear flow of the twin-screw extruder. The morphology developmental mechanism of the dispersed phase involved the formation of sheets, holes and network structures, then the size reduction and formation of nanofibers. The effect of viscosity ratio, blend ratio, and shear rate on the morphology evolution was also studied by analyzing the shape and size distribution of the samples. The diameter distribution of the nanofibers could be affected by viscosity ratio, blend ratio, and shear rate. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Dimethylsulfoxide (DMSO)/urea were chosen as a hybrid solvent system to dissolve soy protein. The dispersion status and rheological properties of soy protein isolates (SPI) in the DMSO/urea were studied. The result showed that SPI has relatively high solubility in DMSO/urea blend system and urea served as a key factor of dissolving SPI in the system. SPI in the DMSO/urea hybrid system exhibited different dispersion statuses with increasing of SPI content. The SPI dispersions in the DMSO/urea presented shear thinning or pseudoplastic behavior. The pseudoplastic behavior, the degree of non-Newtonian flow and the extent of structuralization of SPI dispersion system with increasing SPI content were discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.