A novel mixer-vane mixer which is based on elongation flow was used to prepare high-density polyethylene (HDPE)/montmorillonite (MMT) nanocomposites without any additives. The effect of elongation flow on MMT intercalating in HDPE matrix was studied in terms of rotor speed and mixing time. X-ray diffraction and transmission electron microscope analyses showed that exfoliated and intercalated nanostructures were obtained when the rotor speed was 40 and 50 rpm, and mixing time was 6 minutes. For all samples prepared by vane mixer, MMT layers showed fine intercalation in the nanocomposites. Differential scanning calorimetry and thermogravimetric analysis were used to study the thermal properties of the nanocomposites. The results showed that the addition of MMT can improve the crystallization of the HDPE. Tensile test revealed the relationships between the mechanical properties and process parameters. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42600.

Polypropylene (PP) and poly(styrene-b-butadiene-b-styrene) block copolymer (SBS) were melt-blended in the presence of initiator system. Dicumyl peroxide (DCP)/Triallyl isocyanurate (TAIC) via self-deigned VE, aiming at in situ reactive compatibilization of toughed PP/SBS blend. The reactivity, morphology and mechanical properties of PP/SBS/DCP/TAIC blends were studied. Online torque detection was conducted to monitor changes in viscosities of reactive compatibilized blends, which could give proof of the interfacial grafted reaction induced by DCP/TAIC system. The effect of reactive compatibilization on the dispersed particles sizes and interfacial adhesion was studied by scanning electron microscopy. Analysis on mechanical performance revealed the impact strength improved after treated by initiator system, moreover, the impact-fractured surface observation showed, the failure mode changed from debonding mechanism of neat 50PP/50SBS blend to plastic deformation mechanism of blend containing 3.0 phr initiator system. With improved interfacial adhesion, compatibilized blends not only were toughened but also exhibited enhanced tensile strength and thermal stability. Dynamic mechanical analysis showed a reduction of between PP phase and the PB segments in SBS phase, indicating reactive compatibilization of the blend was achieved. In the final part, a brief discussion was given about the dominant effects from chain scission of PP matrix to intergrafting reactions of PP and SBS, under different content of DCP/TAIC initiator system. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41543.

On the basis of the forces on the differential element in the solids bed, a function between bulk density and pressure, and the nonisotropic pressure distribution in the element, an expression of pressure in the circumferential direction is derived. And the total power introduced through the positive conveying and the friction dragging conveying is also deduced. Experimental data are obtained using a self-developed and simplified vane extruder with an adjustable rotor eccentricity. The solids conveying mechanism in the solids compaction zone of a vane extruder is theoretically and semiempirically confirmed. Besides, the various portions of total power consumption including the power dissipated on the surfaces of the stator and baffles, the power used to build pressure and the power converted into rotational kinetic energy are derived. The effects of the eccentricity on the solids conveying are also discussed theoretically and semiempirically. POLYM. ENG. SCI., 55:719–728, 2015. © 2014 Society of Plastics Engineers

This work aimed to study, for the first time, the melt blending of poly(lactic acid) (PLA) and ethylene acrylic acid (EAA) copolymer by a novel vane extruder to toughen PLA. The phase morphologies, mechanical, and rheological properties of the PLA/EAA blends of three weight ratios (90/10, 80/20, and 70/30) were investigated. The results showed that the addition of EAA improves the toughness of PLA at the expense of the tensile strength to a certain degree and leads the transition from brittle fracture of PLA into ductile fracture. The 80/20 (w/w) PLA/EAA blend presents the maximum elongation at break (13.93%) and impact strength (3.18 kJ/m²), which is 2.2 and 1.2 times as large as those of PLA, respectively. The 90/10 and 80/20 PLA/EAA blends exhibit droplet-matrix morphologies with number average radii of 0.30–0.73 μm, whereas the 70/30 PLA/EAA blend presents an elongated co-continuous structure with large radius (2.61 μm) of EAA phase and there exists PLA droplets in EAA phase. These three blends with different phase morphologies display different characteristic linear viscoelastic properties in the low frequency region, which were investigated in terms of their complex viscosity, storage modulus, loss tangent, and Cole-Cole plots. Specially, the 80/20 PLA/EAA blend presents two circular arcs on its Cole-Cole plot. So, the longest relaxation time of the 80/20 blend was obtained from its complex viscosity imaginary part plot, and the interfacial tension between PLA and EAA, which is 4.4 mN/m, was calculated using the Palierne model. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40146.

Elastomer ethylene–butylacrylate–glycidyl methacrylate (PTW) containing epoxy groups were chosen as toughening modifier for poly(butylene terephthalate) (PBT)/polyolefin elastomer (POE) blend. The morphology, thermal, and mechanical properties of the PBT/POE/PTW blend were studied. The infrared spectra of the blends proved that small parts of epoxy groups of PTW reacted with carboxylic acid or hydroxyl groups in PBT during melt blending, resulting in a grafted structure which tended to increase the viscosity and interfere with the crystallization process of the blend. The morphology observed by scanning electron microscopy revealed the dispersed POE particles were well distributed and the interaction between POE and PBT increased in the PBT/POE/PTW blends. Mechanical properties showed the addition of PTW could lead to a remarkable increase about 10-times in impact strength with a small reduction in tensile strength of PBT/POE blends. Differential scanning calorimetry results showed with increasing PTW, the crystallization temperature (T_c) and crystallinity (X_c) decreased while the melting point (T_m) slightly increased. Dynamic mechanical thermal analysis spectra indicated that the presence of PTW could improve the compatibility of PBT/POE blends. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40660.

Different proportions of nanoscale TiO₂ (nano-TiO₂)-filled polybutylene succinate (PBS) composites were prepared by vane extruder. The crystalline, thermal, dynamic viscoelastic, mechanical, and UV-resistance properties of the composites were studied, and X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis were conducted. Results show that the crystalline structure of the PBS composites did not change with TiO₂ addition. TiO₂ almost has no effect on the crystallization and melting behavior of PBS. Nevertheless, the introduction of TiO₂ has improved the thermal stability, tensile modulus, flexural modulus, and flexural strength of the PBS composites. The UV resistance of the composites has also been significantly enhanced with TiO₂ addition. POLYM. COMPOS., 35:53–59, 2014. © 2013 Society of Plastics Engineers

Adding caulis spatholobi residue fiber (CSRF) to reinforce biodegradable poly (propylene carbonate) (PPC) as a reinforcement was investigated. The morphology of CSRF before and after continuous steam explosion, the mechanical and morphological properties of PPC/CSRF bio-composites with different fiber content were investigated using scanning electron microscopy (SEM), mechanical tests and infrared spectroscopy. The tensile strength and modulus, and impact strength of the bio-composites increased as the content of fiber increased in composites, the elongation at break declined. It was found that a small stay-segment in the stress–strain curves and pulled-out fibers on fractured surfaces of the composites. Infrared spectra result showed esterification and formation of hydrogen bonds between the matrix and CSRF. The fractured surface of the composites addressed a promotion of the interfacial interactions. POLYM. COMPOS., 35:208–216, 2014. © 2013 Society of Plastics Engineers

Low-density polyethylene (LDPE)/nanoprecipitated calcium carbonate (NPCC) nanocomposites were prepared with a self-made vane extruder (VE) that generates global dynamic elongational flow and with a single-screw extruder (SSE) that generates low shear flow. The mechanical properties, dispersed phase morphology, and thermal behavior of the nanocomposites were investigated to compare the different processing techniques. Scanning electron micrograph and transmission electron micrograph show that the elongational flow in the VE improves the dispersion of NPCC (5 wt%) particles in the LDPE matrix. The dimensional distribution of NPCC particles in the VE is significantly lower than that of the SSE. Differential scanning calorimetric curves indicate that dynamic elongational flow can enhance the crystallization ability of the LDPE/NPCC nanocomposites. The mechanical properties of the VE-extruded samples are superior to those of the SSE-extruded samples. When compared with that of SSE, morphology of tensile fracture surfaces suggests that the uniform and fine dispersion of NPCC particles in the LDPE matrix can successfully improve modulus and toughness of the LDPE/NPCC nanocomposites based on the novel VE. POLYM. COMPOS., 35:884–891, 2014. © 2013 Society of Plastics Engineers

Thermoplastic polyurethane (TPU) polypropylene (PP) blends of different weight ratios were prepared with a self-made vane extruder (VE), which generates global dynamic elongational flow, and a traditional twin-screw extruder (TSE), which generates shear flow. The mechanical properties, phase morphology, thermal behavior, and spherulite size of the blends were investigated to compare the different processing techniques. Samples prepared with a VE had superior mechanical properties than the samples prepared with a TSE. Scanning emission micrographs show that the fiber morphology of the TPU/PP blends (<60 wt% TPU) was improved by elongational flow in VE. Differential scanning calorimetry curves indicate that a dynamical elongational flow could improve the miscibility of the TPU/PP blends. The U-shaped spherulite size curve indicates the changes in the spherulite size, as observed from a polarization microscope. Interlocked spherulites also reveal the apparent partial miscibility of the TPU/PP blends under elongational flow. POLYM. ENG. SCI., 54:716–724, 2014. © 2013 Society of Plastics Engineers

An experimental instrument is developed with a purpose to study solids compaction behaviors in vane extruder in a direct manner. The effects of eccentricity, temperature, velocity, and polymer properties on the compressibility of polymer solids are reported in terms of compaction coefficient as a function of rotor torque. The results show that a relatively larger eccentricity or a lower external temperature can bring a smaller compaction coefficient, which results in higher pressure in the solids conveying zone of the vane extruder. However, rotor velocities almost have no influence on the compaction coefficient under the same condition. In addition, a difference is observed between the effects of the semicrystalline polymers and the noncrystalline polymers on the compaction coefficient, which should be taken into consideration in vane extrusion processing operations. POLYM. ENG. SCI., 54:1403–1411, 2014. © 2013 Society of Plastics Engineers

Polylactic acid (PLA)/organo-montmorillonite (OMMT) nanocomposites toughened with thermoplastic polyurethane (TPU) were prepared by melt-compounding on a novel vane extruder (VE), which generates global dynamic elongational flow. In this work, the mechanical properties of the PLA/TPU/OMMT nanocomposites were evaluated by tensile, flexural, and tensile tests. The wide-angle X-ray diffraction and transmission electron microscopy results show that PLA/TPU/OMMT nanocomposites had clear intercalation and/or exfoliation structures. Moreover, the particles morphology of nanocomposites with the addition of TPU was investigated using high-resolution scanning electronic microscopy. The results indicate that the spherical TPU particles dispersed in the PLA matrix, and the uniformity decreased with increasing TPU content (≤30%). Interestingly, there existed abundant filaments among amount of TPU droplets in composites with 30 and 40 wt% TPU. Furthermore, the thermal properties of the nanocomposites were examined with differential scanning calorimeter and dynamic mechanical analysis. The elongation at break and impact strength of the PLA/OMMT nanocomposites were increased significantly after addition of TPU. Specially, Elongation at break increased by 30 times, and notched impact strength improved 15 times when TPU loading was 40 wt%, compared with the neat PLA. Overall, the modified PLA nanocomposites can have greater application as a biodegradable material with enhanced mechanical properties. POLYM. ENG. SCI., 54:2292–2300, 2014. © 2013 Society of Plastics Engineers

This study reports the morphology development of polymer blends in a novel vane extruder in which polymer mainly suffers from elongational deformation field. Rapidly cooled samples of polypropylene/polystyrene (PP/PS) are collected in the vane extruder after stable extrusion. Furthermore, the shape and size of the dispersed phase from initial to final stages are analyzed. In addition, in order to compare the final size of the dispersed phase, different immiscible blends, including polypropylene/polyamide and PP/PS, are prepared by vane extruder and twin-screw extruder, respectively. The results show that the dispersed phase is made to change rapidly from stretched striations to droplets under the strong elongational deformation field in the vane extruder. Furthermore, the droplet size of dispersed phase of blends prepared by vane extruder is much smaller than that prepared by twin-screw extruder, indicating that the vane extruder is more efficient in mixing for immiscible polymer blends. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Polymer granules are conveyed and plasticized using an innovational vane extruder composed of several vane plasticizing and conveying units (VPCUs). This study developed a mathematic model to analyze the bulk density of polymer granules in a VPCU, as well as conducted an experiment to investigate the effects of device geometry, polymer properties, and operating conditions on the model. By comparing the theoretical model data with the experiment data, the proposed model of bulk density is found to be aligned with actual conditions, thus providing a basis for device and process optimization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 842-850, 2013

A 30 wt % high-density polyethylene (HDPE)/70 wt % polystyrene (PS) blends and 5 wt % HDPE/95 wt % PS blends were prepared via polymer vane plasticating extruder, which can generate elongational force field, in different rotation speeds. The fracture surface of the HDPE/PS blends was observed by a scanning electron microscope, and the dispersion of the HDPE in the PS matrix was evaluated by multifractal programs. The multifractal spectrum width , and the dimension difference of maximum and minimum probability subset were defined to discuss the homogeneity and the diameter of the HDPE particles. The results showed that the multifractal method was an effective tool to quantitatively describe the special distribution and diameter of the dispersed particles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2328–2335, 2013

An innovational vane extruder made polymeric materials endure an elongation stress that was much larger than the shearing stress in the extrusion process. The operating principle of the vane extruder was completely different than that of conventional screw extruders. As the first stage of polymer processing in the vane extruder, the process of solids conveying was composed of feeding, compacting, and discharging. Most of the energy was consumed in the compacting process of polymer particulate solids in this stage. A mathematical model was developed to analyze the power consumption in the process. The model showed that the power consumption was mainly influenced by the structural parameters of the vane extruder, including the rotor diameter, eccentricity, and axial width of the vane unit. The analysis indicated that more energy was used to generate pressure in the vane extruder than in a screw extruder. The theoretical model was verified by the experimental results. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Vane extruders are novel polymer-processing equipments, which are composed of a number of vane plasticizing and conveying units (VPCUs). With the vane extruder and the visualization VPCU device, the melting phenomenon of high-density polyethylene (HDPE) pellets under different operation conditions was investigated. It was shown that the positive displacement conveying mechanism and mandatory deformation of particles made the melting evolution in vane extruders totally different from screw extruders. The length of solid conveying and melting zone in vane extruders was much shorter, and the island-sea melting model was formed instead of Tadmor's melting model. Plastic energy dissipation, friction energy dissipation, and viscous energy dissipation were very important sources of heat energy for polymer particles melting in vane extruders. The eccentricity of VPCU, leading to the compression and deformation of particles, was a decisive factor in polymer melting in vane extrusion. Owing to the eccentricity, mechanical energy was dissipated into heat via the deformation of HDPE particles and the thermo-mechanical history was shortened remarkably. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21336; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21336

It is well known that converging channel can generate elongational deformation field. In this study, novel dynamical converging channels were successfully incorporated into plant fiber-reinforced thermoplastics composites processing. A dynamical elongational deformation field (DEDF) generated by these channels was studied. The fiber organization and damage in the DEDF has been investigated in terms of its relationship to changes in rotating speed of the channels. A vane extruder based on these channels was used to prepare sisal fiber-reinforced polypropylene composites. By investigating rapidly cooled samples in the vane extruder, sisal fiber in the center part of these channels has an orientation with an angle to the discharging direction. Rotating speed increases from 30 to 90 r/min result in 30.99–42.7% decreases in average fiber length. The issues of fiber distribution and voids formation have been related to the mechanical properties of the composites, particularly tensile strength and modulus. Increased rotating speeds from 30 to 90 r/min results in tensile strength and modulus increases of about 21.3% and 11.6%, respectively. The majority of this change is caused by decreased voids formation with the increases of speed, which is in agreement with scanning electron microscopy of the composites. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers

Epoxidized soybean oil (ESO) was blended as a novel plasticizer with polybutylene succinate (PBS) in a twin-screw extruder. The effects of ESO on the mechanical and thermal properties of the PBS/ESO blends were investigated by means of tensile test, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and scanning electronic microscope. ESO improved elongation at break for PBS, which increased and then decreased with the increase in ESO. Elongation at break reached a maximum of 15 times than that for pure PBS when the ESO loading was 5 wt%. The tensile strength and modulus for the blends were lower than those for pure PBS. Compared with pure PBS, the blends exhibited lower glass transition temperature, crystallization temperature, and melting temperature. The storage modulus and tan δ peaks for the blends were lower compared with that for pure PBS. ESO had very limited compatibility with PBS, and phase separation was observed when more ESO was added. Copyright © 2011 John Wiley & Sons, Ltd.

The pressure establishment in the solid conveying section of a vane extruder was theoretically and experimentally studied in the present article. Based on the structural and conveying characteristics of the vane extruder, a four-plate model was developed. The effects of the device geometry (eccentricity ε and discharge port β), the polymer properties (different materials), and the operating conditions (temperature and rotating speed) on the pressure were also studied using a visual experimental device. The results showed that the experimental data were highly consistent with the theoretical data, which indicated that the theoretical model was sensible. Considering the optimization design of the device and its processing parameters, the eccentricity ε and the discharge port β of the discharge baffle should be appropriately selected, and the setting temperature of the feeding section should be set to a low value. The rotating speed of the rotor had no significant influence on the pressure establishment. In addition, the thermo-mechanical history of the vane extruder was shorter than that of the conventional screw extruder. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Poly(lactic acid) (PLA) is a well known biodegradable thermoplastic with excellent mechanical properties that is a product from renewable resources. However, the brittleness of PLA limits its general applications. Using epoxidized soybean oil (ESO) as a novel plasticizer of poly(lactic acid), the composite blend with the twin-screw plastic extruder at five concentrations, 3, 6, 9, 12, and 15 wt %, respectively. Compared with pure PLA, all sets of blends show certain improvement of toughness to different extents. The concentration with 9 wt % ESO increases the elongation at break about 63%. The melt flow rates of these blends with respect to different ESO ratio have been examined using a melt flow indexer. Rheological behaviors about shear viscosity and melt strength analysis are discussed based on capillary rheology measurements. The tensile strength and melt strength of the blends with 6 wt % ESO simultaneity reach the maximums; whereas the elongation at break of the blends is the second highest level. ESO exhibits positive effect on both the elongation at break and melt strength. The results indicate that the blend obtained better rheological performance and melt strength. The content of 6 wt % ESO in PLA has been considered as a better balance of performance. The results have also demonstrated that there is a certain correlation between the performance in mechanical properties and melt rheological characterization for the PLA/ESO blends.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A self-developed experimental facility by the National Engineering Research Center of Novel Equipment for Polymer Processing, called a coaxial barrel dynamic rheometer, was used to test the predictability of the apparent viscosity equations of polymer melts in flat vibrating shear flows. The testing principle of the rheometer is to transform the shear power of a motor and extrusion pressure in a shear field to melt viscosity. The shear field can simulate an orthogonal superposed vibratory flow, boundary vibrating pressure flow, and their combined flow. By comparing equation predictions with experimental results, we show a qualitatively satisfactory and quantitatively reasonable predictive ability, which verifies the work of our mathematical derivations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The melting of polymers caused by friction before a solid plug is an important phenomenon in the vibration-induced plastic extrusion process. In order to better analyze the melting process of polymers in a vibration screw type extruder, a melting model is proposed as well as a corresponding experimental apparatus to test the model. Due to the introduction of vibration force field, the viscidity of a polymer melt behaves in a strong non-linear and time-dependent fashion. Therefore, the effect of heat generated by viscous dissipation is very important. Through sophisticated deduction, an analytical expression of the relationship between the velocity of polymer solid element and the parameters of vibration is derived. The model is then proved by comparing a calculated sample with experimental results, which indicate that, the introduction of vibration force field can improve the melting process to a great extent. This model can serve as the theoretical basis for a polymer melting process. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers