Preparation, Structure And Performance Of TPU Toughening Composite Based On Elongational Deformation

Polymer plasticizing conveying mechanism based on elongational deformation is a novelnon-screw dynamic plasticizing processing method dominated by elongational deformation. Itis a great change of polymer processing theory from shear flow to elongational flow, breakingnew ground on polymer processing technology. Polymer dynamic plasticizing processingequipment based on elongational flow has advantages over screw equipment in low energyconsμmption, extensive adaptive for materials and small volμme. Therefore, the deeplyresearch on the dispersed mixing process of incompatible plastic is of great significance to thepopularization and application of polymer plasticizing conveying method and equipmentbased on elongational flow.Thermoplastic polyurethane/polypropylene composite was prepared by Vane plasticizingconveying technology based on elongational deformation. The results were compared to thatprocessed by conventional shear flow, revealing the effect of plasticizing conveyingtechnology dominated by elongational flow on the structure and performance of composite.The results reveal that dispersed phase become in-situ fibrillation under the combined actionof axial flow and circμmferential flow in vane unit. The composite has smaller and narrowerparticle distribution, better crystal texture, thermal stability and compatibility, ultimatelydemonstrating better mechanical performance.High-performance thermoplastic polyurethane/polylactic acid composite was preparedby vane plasticizing conveying technology dominated by elongational force, and therelationship between dispersed phase content and mechanical performance was established.The results show that thermoplastic polyurethane toughens polylactic acid evidently. Theunique fiberlike texture makes the tensile strength with high content larger than that with lowcontent.Biodegradable polylactic acid/nanoclay composite and thermoplasticpolyurethane/polylactic acid/montmorillonite nanocomposites were prepared by VaneExtruder based on elongational flow. Montmorillonite presents intercalation and exfoliationstructure. Exfoliation increases with the content of montmorillonite. All of the modulus ofcomposites are higher than polylactic acid, with unique “bimodal melting peak” and reducedmelt temperature on melting curves. It states that the composites experience short heat historyand small damage during the extrusion in vane extruder, and molecular chains line array andordered orientation.The synergy of nano particle network configuration and elastomer underelongational flow was also investigated. The results show that the stiffness and toughness of composite increase evidently with the tensile strength remaining high level. The compositefinds a proper equilibriμm between strength and toughness.Besides, in the effect of VaneExtruder elongational flow exfoliated montmorillonite platelets present a convergent structuredecreasing the resistance during polymer intercalation, which makes the montmorilloniteplatelets exfoliate more effectively and homodisperse in polymer matrix. According to that,“double platelets exfoliation” mechanism of montmorillonite is put forward in the effect ofelongational flow.Polymer plasticizing conveying method and equipment based on elongational flow arebrand new polymer processing theory and equipment. Creative progress has been made in theresearch about polymer preparation and processing theory. Brand new preparation processingtechnology of polymer composite reaches a certain scale and many key technical problemsleft by conventional processing method have been solved. It lays the first stone of furtherresearch about extrusion process and principle of vane plasticizing and provides the basis ofthe popularization and application of vane plasticizing conveying equipment.