Study On Structure And Performance Of PA6/TPU/MMT Composites Processed By Vane Extruder

Polyamide6(PA6), engineering plastics with high mechanical strength, thermalresistance, oiliness resistance and so on, has been widely used in many field. However itsdefects, such as low stability of dimension, high water absorption,and low impact strength atlow temperature and dry circumstance, limit the range of its applications. Thus, properties ofPA6should be improved by blend, strengthening, filling and compounding, and many PA6based products with good characteristics can be developed.Molding equipment and processing technology plays an important role for aggregationstructure of the material, dispersed and mixed conditions and macro-mechanical properties ofpolymer materials. Different from screw, which is regarded as the core part for traditionalpolymer processing devices and the processing methods are based on the shear flow, vaneextruder without screw invented by Prof. Qu, which is a new polymer processing device andthe processing methods are based on elongational deformation. Compared with traditionalprocessing equipment-screw extruder, vane extruder has the unique advantages, such as smallin size, low energy consumption for processing and the wide materials adaptability. Study ondispersion mixing of polymer composite system, the crystallization and mechanical propertiesof polymer materials, which base on the volume elongational deformation, has importantsignificance for the development of polymer processing principle of volume elongationaldeformation, for promoted the development of polymer materials, for advanced processingtechnology and equipment.The PA6/TPU toughened blends are prepared by Vane Extruder, adjusting the processparameters and component parameters. Morphologies of prepared blends are characterized byscanning electron microscope (SEM). Differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), wide angle X-ray diffraction (WAXD) and dynamicmechanical analysis (DMA) are used to characterize the thermal behavior and crystallinestructure of the blends. The mechanical properties of blends, such as tensile, flexural andimpact properties are tested. Compared with the twin screw extruders, the results show thatthe increase amplitudes of tensile modulus and flexural modulus of blends are respectively30.3%and40.6%, and the TPU phase dispersed uniformly in PA6matrix displays oval shapestructure, implying that reinforcement of blends was prepared during processing.The PA6/MMT reinforced composite materials are prepared by Vane Extruder, theeffects of MMT content on composite materials has been discussed. Under the effect ofvolume elongational deformation, the MMT sheets uniformly dispersed in the PA6matrix, presents intercalation and exfoliation structure. MMT promotes the crystallization of PA6, andthe γ-crystallization form is enhanced by the additive of MMT, while the α-crystalline form ishindered and even disappeared. As MMT content increases, the heat distortion temperatureincreases to a great extent. As MMT content increases, storage modulus, tensile strength,tensile modulus, flexural strength, flexural modulus of PA6/MMT reinforced compositematerials also increasing. Compared with pure PA6, the results show that tensile modulus,flexural modulus, tensile strength and flexural strength were increased33.3%,57.4%,19.1%and25.8%.Comparison structure and morphology, the dispersed phase distribution, particle size,thermal properties, thermal stability of PA6/TPU, PA6/MMT, PA6/TPU/MMT composite,Find a single enhanced toughness decreases, single toughened strength. Some properties ofthe composite caused by the problem of lack of action for a single material, in thesimultaneous addition of TPU and MMT in PA6, combined with the characteristics of themodified elastomer and nano materials prepared PA6/TPU/MMT composites, whileimproving the strength and toughness. Compared with pure PA6, the tensile modulus, flexuralmodulus, elongation at break, the impact strength of PA6/TPU/MMT composites wereincreased33.3%,57.4%,19.1%and25.8%.The experimental provide further research aboutextrusion process and principle of vane plasticizing and application of vane plasticizingconveying equipment and provides the basis of the popularization and provides support forMMT and TPU mechanism of synergistic toughening PA6, lay the foundation for thepreparation and processing of composites.