| Polyamide is one of the most popular used polymer in general material area in recent years,and it has been widely and systematically researched.It is a highly feasible way to explore new polymer composite systems applicating in new fields.Carbon materials show a regular structure and excellent mechanical and electrical properties,and are applied in composite in the meanwhile.They remain outstanding advantages in improving and changing the structure of polymer blended systems.On the one hand,carbon materials such as graphene oxide?GO?,carbon nanotubes?CNT?,and carbon fibers,can effectively improve the shortcomings of polyamide materials with high hygroscopicity and poor low temperature toughness.On the other hand,the excellent features of GO and CNT are the reason of application in many fields,such as?1?light weight,?2?controllable conductivity,?3?high thermal stability,?4?high thermal conductivity,?5?high strength,high modulus,and so on.It is helpful to find the new path for the research and application of insulating polyamide materials in the field of electromagnetics and contral system.In the research,polyamide 6/11/Carbon composite systems were prepared by in-situ polymerization,and then PA6/11/GO and PA6/11/CNT composite fibers were spun by a melt-spinning process.FT-IR spectroscopy was used to trace the group changes inside the molecular after polymerization;X-ray diffraction?XRD?and scanning electron microscopy?SEM?were used to characterize the crystal structure and dispersion state of carbon nanomaterials inside PA6/11 matrixs;Difference scanning calorimetry?DSC?and thermogravimetric analysis?TG?are used to explore the thermal properties of PA6/11/GO and PA6/11/CNT composite fibers.The effects of two different structures of carbon nanomaterials on the mechanical properties and electrical conductivity of the polymer PA6/11 matrix were analyzed at the same time.Reserch results showed that:?1?When the amount of GO added is0.50wt%in PA6/11/GO composite fiber,the mechanical tensile strength of the fiber can reach610MPa,and the elongation at break is 30%.Compared with the copolymerized PA6/11 fiber,the tensile strength and elongation at break are increased by 18.9%and 40%by 513MPa and18%.When the addition amount of GO is 1.00wt%,the saturated water absorption rate of the composite fiber decreases by 61.62%.When the amount of GO added is 1.00wt%,the conductivity of the composite matrix reaches 3.4×10-9S/m.?2?When the amount of CNT added is 2wt%,the tensile strength and elongation at break are 564MPa and 19%.Compared with the copolymerized PA6/11,the strength is increased to 9.9%,and the elongation at break is increased by 5.6%,The improvement effect is not obvious comparing to the effect of GO.The saturated water absorption rate at 2.0wt%is improved by 59.6%.When the added amount is5.00w%,the conductivity can reach 9.3×10-7S/m.Compared to CNTs in the one-dimensional nanoscale range,GO,a two-dimensional carbon nanomaterial,has certain advantages in promoting the crystallization process of the polymer PA6/11 matrix and repairing internal defects. |
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