A Study On Structure And Properties Of Poly (Ether Sulfone)/MC Nylon 6 In-Situ Composites

In-situ polymerization was a new method to prepare polymer/polymer composite. It created the rigid macromolecular with the matrix at the same time, blended the two polymers homogeneously, avoided the tendency of the phase separation between the macromolecules to the most and gained the higher level dispersion. In addition, its technics was easier and it conquered the limitation of generic preparation methods such as melt blend and solution blend. It has been rarely reported to prepare the poly(ether sulfone)(PES)/MC nylon 6 composite via in-situ anionic polymerization so far. On the basis of PES able to dissolve in the ε-caprolactam melt, PES/MC nylon 6 in-situ composite was successfully obtained via anionic polymerization. The interaction between PES & ε-caprolactam, PES & ε-caprolactam-NaoH, and PES & MC nylon 6 matrix were studied in detail. The dispersion state of PES in MC nylon 6 was also characterized. Furthermore, the crystallization behavior, melting behavior, crystalline structure, thermal stability, mechanical properties as well as failure morphology of PES/MC nylon 6 composites were investigated. Meanwhile, the effect of PES on structure and properties of PES/MC nylon6 in-situ composites was illustrated compared to pure MC nylon 6. The main results were summarized as follows:1.There existed hydrogen-bonds interaction between PES & ε-caprolactam, PES & ε-caprolactam-NaoH, and PES & MC nylon 6 matrix systems. SEM photographs showed PES well dispersed in MC nylon 6 matrix. With the content of PES enhancing, the interactive points between PES and MC nylon6 increased; the total interaction between them improved, however, the aggregation effect became stronger, causing bigger phase section.2.The interaction of hydrogen-bonds between PES and MC nylon 6 hindered the crystallization of MC nylon 6; the melting behaviors ofcomposites corresponded to the melt of different crystalline structure and crystalline with different perfect level, attributing to the recrystallization and reorganization.3.The crystalline structure appeared mainly in a form in both pure MC nylon 6 and composites, while merely y form presented in samples quenched in liquid nitrogen from melt, a form and y form coexisted in quenched samples annealed at 200°C for 2hr. The interaction between PES and MC nylon 6 hindered the transition of y form to a form. However, nothing but a form presented in quenched samples annealed at 210°C for 2hr. This illuminated higher annealing temperature was in favor of y form to a form.4.The results of composites treated by aqueous solution of KI/I2 indicated PES hindered the transition of a form to y form; the longer treating time did the transition of a form to y form of pure MC nylon 6 a favor. However, the variety of crystalline structure of composites with treating time of aqueous solution of KI/I2 was more complicated.5.The strong hydrogen-bond interaction between PES and MC nylon 6 improved the thermal stability of MC nylon 6. PES hindered the degradation of the first step.6.Compared to pure MC nylon 6, lower content of PES had little effect on mechanical properties; higher content of PES improved the toughness of composites, but the rigidity has some loss. The results of SEM showed the failure morphology of composites with lower content of PES was brittle-tough failure, similarly to the pure MC nylon 6; while the failure morphology of composites with higher content of PES was tough failure.