Study On Structure And Properties Of Nylon Composite Reinforced By Talc Filling

Fillers enhanced modification is an effective way of nylon high strength and highmodulus, and effective combination of different fillers can play their respectiveadvantages and demonstrate a synergistic effect. Talc as a lamellar filler which has alarge ratio of radius to thickness can effectively improve strength and rigidity of thepolymer.In this paper, the enhancement of nylon6（PA6）, nylon66（PA66） with lamellarTalc and synergistic effect of lamellar Talc with fibrous glass fiber （GF）, lamellar Talcwith spherical CaCO3were studied. Talc/PA6, Talc/CaCO3/PA6, Talc/GF/PA6,Talc/PA66, Talc/PA6/PA66, Talc/GF/PA66and other composite materials wereprepared through melt blending, meanwhile the influence of component content anddifferent particle combination on PA6, PA66performance were discussed. Themechanical performance was examined by Mechanical properties test. In addition, themelt and non-isothermal crystallization, thermal properties and micromorphologywere investigated by Different Scanning Calorimeter （DSC）, Thermogravimetry （TG）and Scanning Electron Microscope （SEM）.Mechanical testing analysis showed that Talc, Talc/CaCO3and Talc/GF caneffectively reinforce nylon. In PA6enhanced system, the tensile strength and flexuralstrength increased with Talc content, while the content was at30wt%, it reached itsmaximum. The two strengths of Talc （30wt%）/PA6composite increased17%and61%respectively that compared with pure PA6. when filler content kept at30wt%,the tensile and flexural strength of Talc（27wt%）/CaCO3（3wt%）/PA6andTalc（10wt%）/GF（20wt%）/PA6composites were significantly improved than PA6.Among PA66enhanced system, Talc can not only has an enhance effect but also has aductility one. The impact strength of Talc （10wt%）/PA66composite increased21%than PA66while the tensile strength and flexural strength of Talc （30wt%）/PA66composite increased by3%and14%respectively. The combination of Talc and GFhas an apparent synergistic effect on PA66. Compared with PA66, the tensilestrength, flexural strength and impact strength of Talc （5wt%）/GF （25wt%）/PA66composite were increased by15%,35%and35%respectively.DSC analysis demonstrated that the participation of the lamellar Talc, sphericalCaCO3and fibrous GF has little effect on the melting process of the system, and Tm changes in a small range. On the contrary, the impact on the non-isothermalcrystallization process of the system was quite obvious. These fillers made thecrystallization onset temperature T_on, crystallization peak temperature Tcandcrystallinity Xc of the composite increase, undercooling degree reduce and the halfcrystallization time T_1/2extend. Fillers had an effect of heterogeneous nucleation onnylon which accelerates the nucleation rate. But the high temperature crystallizationand hinder the movement of the macromolecular chains made the overallcrystallization rate slow down.TG, SEM test analysis indicated that lamellar Talc hindered the diffusion of smallmolecules and to some extent delayed the thermal degradation of nylon. The lamellarTalc dispersed in the nylon matrix and oriented obviously along the flow directionwhich was good for nylon enhancement. Talc/CaCO₃formed more holes and crazingin the matrix in order to reflect the synergistic effect of the lamellar and sphericalfillers in impact strength. Talc/GF formed a special multi-dimensional networkstructure in the matrix when nylon reinforcing produced the synergistic effect oflamellar fillers and fibrous fillers.