Synthesis Of Poly(Imion Ketone)s Via C-N Coupling Reaction And Corresponding Molecular Simulation And Structural Modification

As a kind of indispensable high performance polymers, Polyaryletherketone (PAEK) are applied widely in aerospace, nuclear power, electric products and precision machines. And due to their outstanding properties, such as withstand high temperatures, radiation resistance, high intensity, high modulus, PAEK play a key role in these crucial departments. However, because of the defects existed in these commercialized products, researchers are forced to develop more perfect materials to meet the demands caused by the markets. At present, computer simulation, a kind of research method with short study cycle, low cost and the ability to calculate the relationship between the structure and properties exactly, is a new subject developed these years which has significant scientific value on research except experiment and theoretical analysis.Poly(imino ketone)s (PIKs) have been synthetized and applied primarily in recent years. As a novel class of heat-resisted polymers, these materials with high thermal stability, excellent solubility have received close attention nowadays. It can be concluded from the theoretical analysis results that PIKs possess perfect physical properties, that's because of the aromatic rings were linked by the imino and carbonyl groups, these polymers can be considered as a compages composited by PEKs, PANI and PI. However, the defects such as the fewer varieties, lower-mass, expensive catalyst, the addition of deficient theory and experiment to explain the relationship between structure and properties, seriously limit the applcation of the PIKs. Our research began with the molecular simulation by materials studio (MS), it aimed at obtaining the properties of PIKs we designed via the simulated results. On this basis, the modified polymers were obtained as novel functional materials by the special groups which were embedded into the molecular chains. And then, high-performance films were prepared and applied by using the modified products. In addition, many problems are existed in synthetizing PIKs via palladium catalyst, such as expensive catalyst, too many steps, and so on. Our research were focused on copper catalysts instead and nucleophilic substitution to solve the problems. The summary of our research was enumerated as follows:(1) A series of PIKs were obtained via varying the ratio between the amount of imino groups and carbonyl groups, and their properties were calculated after molecular simulation by MS. It can be concluded from the results that it's a reasonable method to calculate the relationship between structure and properties, because the calculated results agreed with the experiment ones very well.(2) PIKs were modified with the functional groups which were embedded into molecular chains, mainly in two parts: First, the ether bonds were used to increase the reactivity of the molecular chains, it aimed at increasing the molecular weight and improving the solubility of the polymers. Second, modified PIKs have been obtained by introducing the cardo group or fluorene groups into the polymer chains. The conclusion by MS calculated that the modified PIKs possess exectllent performance, such as: good thermal stability, better solubility, and then the results were proved by the test ones. Additionally, because of the presence of fluorene group which brought optical properties, these novel conjugated polymers provide new choice for the light-emitting materials.(3) New catalyst systems and synthesis methods were developed to overcome the defects existed in the primitive way. There are two parts mainly: First, the low-priced copper catalyst systems were used to instead of the palladium catalyst systems. New synthesis method was developed to obtain PIKs, it comes from the fact that nucleophilic substitution. This method is simple and needs no catalyst systems, high molecular weight PIKs were prepared in a short time.(4) The initial application of the modified PIKs was researched. High performance films have been prepared by hot-pressed or solution cast method. The tests showed that the films we prepared possess excellent properties, such as high transparency, high index of refraction, excellent mechanical properties and the others.