Research On The Preparation And Properties Of PA6 Composite Materials Based On Nano-titanium Dioxide

Polyamide 6?PA6?is a thermoplastic polymer with a high degree of concern in the study of composite modification.It has been widely used in engineering plastics,films and fibers,which has good processability and chemical stability.However,PA6has poor dimensional stability,low limit oxygen index?LOI?,and belongs to combustible materials.The strength of PA6 materials tends to decrease by means of the addition of flame retardants.Therefore,it plays an important role in the modification of enhance and flame retardant.This paper mainly aimed to add nano-Ti O₂in the early stage of PA6 polymerization by means of in-situ polymerization,and then add a certain amount of PEG?polyethylene glycol?and nitrogen-based flame retardant MCA in the late stage of polymerization to form PA6/PEG/Ti O₂ nanocomposite with good mechanical and optical properties.,PA6/MCA/Ti O₂nanocomposite with good mechanical properties and flame retardancy.The performance characterization test of PA6/PEG/Ti O₂ composites was conducted.The chemical composition was studied by X-ray photoelectron spectroscopy?XPS?,and the cross-sectional morphology and structure were studied by scanning electron microscope?SEM?.The differential scanning calorimetry?DSC?,X-ray diffractometer?XRD?,and thermogravimetric analysis?TG?were used to explore the crystal structure,properties and thermal properties of the modified composites;The mechanical properties of composite materials was characterized by tensile testing;the viscoelastic behavior of materials was analyzed by dynamic rheological testing.The relationship between the static shear rate,the shear viscosity and the shear stress;the photocatalytic experiments were carried out by hot-pressing the film of a plate vulcanizer,and the optical properties of the composites were discussed.The results show that the nano-Ti O₂ and PA6/PEG/Ti O₂ composites have good matrix compatibility.The addition of nano-Ti O₂ improves the polymer's thermal stability and crystallization.The breaking strength of the composite reaches 49.49 MPa,and the elongation at break reaches 180.58%.The catalytic degradation ability reaches about75%.PA6 and modified PA6 composite materials are all non-Newtonian fluids,and the shear force becomes thinner throughout the test.The performance characterization of PA6/MCA/Ti O₂ nanocomposite was tested.The structure of the material was characterized by Fourier transform infrared spectroscopy?FT-IR?and scanning electron microscope?SEM?.The differential scanning calorimeter?DSC?and X-ray diffractometer?XRD?were used to analyze the crystalline and thermal properties of materials.The flame retardancy of materials was carried out through the limit oxygen index test and vertical combustion.The mechanical properties of composite materials was expressed by tensile test and the material's rheological properties was showed by dynamic rheological test Viscoelastic behavior.The results show that the introduction of nano-Ti O₂ makes the crystal structure of PA6/MCA/Ti O₂ composites relatively stable,the crystallinity and melting temperature increase have been increased,the breaking strength reaches 44.26MPa,and the LOI value of the sample reaches 28.9%.Dynamic rheological tests show that appropriate amounts of nano-Ti O₂ and MCA can improve the storage modulus,loss modulus,and complex viscosity of PA6/MCA and PA6/Ti O₂ systems.In general,this research has great theoretical and practical significance for flame retardant reinforced modified PA6 for industrial and decorative fabrics.