Surface modification of nylon 66 fiber and its reinforcement of coordination crosslinked acrylic rubber

The interface compatibility between the surfaces of nylon 66 (PA66) fiber and the acrylic rubber (AR) is the key factor to improve the mechanical properties of the composite materials. In this study, Lewis acid (CaCl2) was firstly used to reduce the crystallinity of PA66 fiber, and then a bioinspired polydopamine (PDA) function coating was constructed on the PA66 fiber surface to act as a bridge to introduce an epoxy-functionalized silane layer (KH560). After that, the modified PA66 fiber was introduced in the CuSO4 coordination crosslinked AR composites to further increase the mechanical performances of AR. Results showed that Lewis acid could significantly reduce the surface crystallinity of PA66 fiber, the PDA coating has successfully coated the fiber surface. And SEM results showed, the interfacial compatibility between the fiber and rubber was obviously improved. Compared with the unmodified PA66 fiber filled AR composites, the tensile strength, modulus and hardness of the modified PA66 fiber filled AR composites were increased by 95%, 49%, and 16% respectively.

Automated summary

In this study, Lewis acid (CaCl2) was used to reduce the crystallinity of PA66 fiber, and then a bioinspired polydopamine (PDA) function coating was constructed on the fiber surface. The modified PA66 fiber was introduced in the CuSO4 coordination crosslinked AR composites to improve the mechanical performances of AR, and the interfacial compatibility between the fiber and rubber was obviously improved.