One-step Eco-friendly Fabrication of Antibacterial Polyester Via On-line Amination Reaction by Melt Coextrusion

The work is dedicated to develop a one-step eco-friendly method to prepare antibacterial polyethylene terephthalate(PET).We report a one-step eco-friendly method to manufacture antibacterial PET via on-line amination reaction by melt coextrusion.Beside evenly mixing of poly(hexamethylene guanidine)(PHMG)and PET in the melt coextrusion procedure,the amination reaction also occurred between PHMG and PET under high temperature(230-270℃).The antibacterial ability of composite PET showed obvious PHMG concentration dependence,and antibacterial activity reached more than 99%when PHMG content was 2.5 wt%.Moreover,LIVE/DEAD fluorescence test further confirmed that the composite PET could kill bacteria quickly and efiectively(within 30 min);while negligible cytotoxicity was observed to HSF and HUVEC cells.Onestep eco-friendly fabrication of composite antibacterial PET was accomplished by on-line melt coextrusion.The composite antibacterial PET has potential use in multiple fields to combat with pathogenic including textiles,packaging materials,decoration materials and biomedical devices,etc.

Latice Deformation and Meso-Phase Structure in Poly(Ethylene Terephthalate)From Solid State Coextrusion

The development of crystalline and Meso-phase structure by solid state extrusion from50℃ to 90℃ is studied for PET. The unit cell parameters of stress-induced crystallites inextrudates are determined as a function of extrusion draw ratio (EDR), and

Orientation of LDPE Crystals from Microscale to Nanoscale via Microlayer or Nanolayer Coextrusion

Abstract The microlayer or nanolayer coextrusion of hundreds or thousands of alternating low density polyethylene （LDPE）/polystyrene （PS） microlayers or nanolayers were used to study the orientation of LDPE crystals in the confined quasi-two-dimensional or two-dimensional space. The clear and continuous layer structures from microscale to nanoscale can be found in SEM images. The morphology evolution of LDPE crystals in the confined microlayer or nanolayer can he varied from 3D spherulites, 2D spherulites, stacked edge-on lamellar, to single edge-on lamellar. Due to the orientation of the LDPE crystals, the tensile strength of the films increases obviously when the layer thickness reduces to nanoscale. The 2D small angle X-ray scattering （SAXS） patterns can reflect the average degree of orientation of LDPE in the confined layers. The stacking of LDPE lamellae is suppressed in interlamination and oppositely in parallel to the extrusion direction. The specific orientation function f can be calculated from the patterns. The infrared dichroism further confirms the mutation of the orientation of LDPE crystals from microscale to nanoscale in the confined space.

Foam/Film Alternating Multilayer Structure with High Toughness and Low Thermal Conductivity Prepared via Microlayer Coextrusion

Multilayer membranes prepared via microlayer coextrusion have attracted wide attention due to their unique properties and broad applications.In present study,the foam/film alternating multilayer sheets based on ethylene-vinyl acetate copolymer(EVA)and high-density polyethylene are successfully prepared via microlayer coextrusion.The cells in the sheets are single-cell-array along the foamed EVA layers with uniform cell size.In addition,the effects of layer number and foam relative thickness on morphology,mechanical properties,damping and heat insulation properties are investigated.The cell size decreases significantly with increasing layer number due to the enhanced confine effects.The tensile strength,elongation at break,and heat insulation also increase significantly.However,the mechanical damping properties change little in the observed frequency.Meanwhile,with higher relative thickness of EVA foam,the sheets have lower tensile strength and lower thermal conductivity,while the damping properties are enhanced in a specific frequency scope.The elongation at break of the optimized sample comes to 800%and the thermal conductivity decreases to 61 mW·m^(-1)·K^(-1),which shows high toughness and low thermal conductivity,indicating a possible method for preparing materials with high toughness and heat-insulating properties.