Synthesis And Properties Of Nylon 6/66/510

A In this work, nylon 6/66 and nylon 6/66/510 containing 5～20 mol% nylon-510 were synthesized to be used as hot melt adhesive for metal plate with low-surface-energy coating. The effects of mole fraction of nylon-510 (Xm) on the thermal and mechanical properties of nylon 6/66/510 were systematically studied. The results demonstrate that:(1) when the Xm increases, the melting point of the copolyamides decreases from 167.3℃ to 126.9℃, and its glass transition temperature decreases from 46.7℃ to 24.3℃; (2) the tensile strength of nylon 6/66/510 remains almost unchanged and is almost equal to that of nylon 6/66; (3) the elongation at break of nylon 6/66/510 is significantly higher than that of nylon 6/66. The adhesion of nylon 6/66/510 to aluminum sheet with low-surface-energy coating was studied, and the results showed that the peeling strength of nylon 6/66/510 reaches a maximum value when Xm=15mol%.The values of t1/2 and the equilibrium melting temperature for all samples were calculated by Avrami equation and Hoffman-Weeks, respectively. The crystal structure of the copolyamides were also investigated by wide-angle X-ray diffraction (WARD). The results shows that:(1) Avrami model can be used to well describe the isothermal crystallization behavior of the copolyamides, and all the values of t1/2 increase with increasing the Tc or the mole fraction of nylon-510. (2) The crystallization activation energy (ΔE) and nucleation constant (Kg) both increase with increasing the mole fraction of nylon-510, which indicating that the addition of nylon nylon-510 decreases the crystallization rate of copolymer.