Study On The Structure And Properties Of Novel PPESK Containing Phthalazinone Moieties And Its Blends

Poly(ether sulfone ketone) containing phthalazinone moieties, a series of novel high performance polymer developed by our teamwork, have much better thermal resistance and solubility than similar high performance polymers. For better properties, the polymers have a strong competitive capability in international market. However, the pure resin shows some shortcomings in processing and application. For example, the melt viscosity is too high to process and the brittleness is unbeneficial to commercialization. Therefore, blending PPESK with other high performance polymers was adopted to improve their properties. In this paper, structures and properties of their blends were studied systematically, which was foundations in their industrialization and application.The kinetics of thermal degradation of poly (phthalazinone ether sulfone) (PPES), poly (phthalazinone ether sulfone ketone) PPESK(50/50) and poly(phthalazinone ether ketone ketone) in nitrogen were studied at several heating rates by thermogravimetry analysis (TGA). According to Satava method, the thermal degradation mechanism of PPESK(50/50) is randomly nucleating and nucleus growth, and order of reaction n=l. The thermal degradation mechanism of PPES, however, is phase boundary controlled reaction and order of reaction n=2 and the three dimensions dispersion for PPEKK. The kinetic parameters, including the reaction active energy and the frequency factor of degradation reaction for PPES, PPESK(50/50) and PPEKK were analyzed by isoconversional Friedman, Kissinger-Akahira-Sunose(KAS) and Ozawa methods. The aim of this paper was to study on the effect of heating rates and ratio of ketone/sulfone on the thermal degradation and the life estimation. On basis of the kinetic parameters, the lifetime for high temperature has been calculated and the 'Kinetic Compensation Effects'(KCE) in the thermal degradation process was analyzed.In the present work, blends of poly (phthalazinone ether sulfone ketone) (PPESK) /poly(tetrafluoroethylene) (PTFE) with various weight ratios were prepared by solution mixing. The dynamic mechanical properties including the storage modulus(E'), loss modulus(E") and loss tangent were studied over a wide range of temperature and frequencies and compared for PPESK and its blends. The results show that novel PPESK possesses high storage modulus within a high temperature range and show good thermal stability. The peaks representing the loss modulus andtan d of blends shifted to higher temperatures with increasing scanning frequency. The thermal stability of polymer is increased with increasing the proportion of sulfone linkages in the backbone. And the Arrhenius relationship has been used to calculate the activation energy of the glass transition of PPESK and its blends.The mechanical and thermal properties of poly(phthalazinone ether suflone ketoneXPPESK)/poly(aryl ether sulfone)(PES) blends prepared by melt-mixing were investigated by dynamic mechanical thermal analysis(DMTA) and thermogravimetric analysis(TGA). The dynamic mechanical thermal analysis results show that the incorporated PES has a large influence on the heat stability of PPESK. The DMTA results display that the blends with a single glass transition temperature, which increases with increasing PPESK content, indicates that PPESK and PES are completely miscible over the studied composition range. The thermodegradative behavior of blends was used to analyze their thermal stability. The Friedman technique was used to determine the kinetic parameters i.e the apparent activation energy and order of reaction of the degradation process. On the basis of the kinetic data derived from Friedman's approach, the lifetime estimates for pure PPESK, pure PES, and the blends generated from the weight loss of 5% were constructed.Miscibility and thermal properties of PPESK/ polyarylate (PAR) have been investigated using differential scanning calorimetry (DSC), DMTA, scanning electron microscope(SEM) and TGA. These blends show a single and composition-dependent glass transition temperature over the entire composition range by DSC method. However, it showed that these blends are partially miscible by DMTA. Thermodegradative behaviour of blends was studied by dynamic thermogravity in order to analyze their thermal stability. The Friedman method was used to determine the kinetic parameters-the apparent activation energy (Ea). The results indicate that the presence of one component influences the thermal stability of the other. Temperature for 5% weight loss, and Ea for blends show a negative deviation from the linear behaviour, which signifies a lowering of thermal stability compared to homopolymers.Artificial neural network (ANN) was applied to forecast the properties of composites based on PPESK. Samples data of TK reinforced composites were applied to train the ANN by neural network tool of MATLAB 6.5. Back-propagation (BP) neural network was established and the optimum parameters of ANN were chosen. The properties of composites based on PPESK were forcasted by the trained ANN. The results show that the train ANN can exactly forecast the properties of composites. ANN based on MATLAB 6.5 also offers an efficient and credible method for analyzing the effect of components.