The Monomer Foaming To Fabricate Polyamide 6 Foam

Plastic foam has become a very important kind of modern polymer materials due to its excellent performance since its inception. Foam plastic has been gradually developed to high performance with the social progress. In this paper, foam nylon 6(PA6F) was successfully prepared by using ε-caprolactam(CPL) as monomer, sodium hydroxide(NaOH) as the initiator of the ring opening polymerization of CPL and modified(CPL-TDI-PFPE-TDI-CPL) as the activator. The chemical structure, state of aggregation and mechanical properties of PA6 Fs were characterized with FTIR 、SEM、DSC、TGA、XRD and mechanical testing.In addition, the monomer foaming mechanism was demonstrated, and then the shearing sublimation foaming mechanism was proposed by us. Finally, a series different state of fumed silica were used as a kind of nucleating agent to improve the properties of the foamed nylon 6.CPL-TDI-PFPE-TDI-CPL was prepared by bulk polymerization, and the structure of the product was characterized by FTIR whose results showed that the modified activator was prepared successfully. Then, a series of PA6 Fs were synthesized at different reaction conditions. The results indicated that reaction temperature, initiator content and modified activator content all had significant impact on structures and properties of PA6 F.At the same time, the surface component of cell and tension of CPL were characterized with EPMA,and the result showed that the content of Fluoride appeared regularly changing. Then the shear sublimation foaming mechanism was proposed by us by taking reference to cavitation phenomenon of water under the action of shear force and ultrasonic wave,and the phenomenon of monomer foaming can be explained reasonablely by this mechanism.At last the critical shear speed was studied.Finally, combining different factors of foaming, nanoparticles(fumed silica)were used as a kind of nucleating agent to control the cellular structure, and the influence of different particle size and content on the density of the foam and mechanical properties of PA6 F were studied respectively.