| Epoxy resin (EP) is widely used as adhesive and coating in aviation&spaceflight, electron instrument and architecture fields for its outstanding advantages on excellent mechanical, low shrinkage during cure, high adhesive strength, good chemical resistance and aging resistance. While their applications are limited in many high-tech fields as their brittleness, poor toughness and low heat-resistance. One of the effective way to overcome this problem is using thermoplastics (TP) to modify epoxy resin without reducing their other advantageous properties. Soluble poly(ether ether ketones) were employed to modify epoxy resin on the base of poly(ether ether ketone) modified epoxy resin. The aim of this study is to prepare a series of high toughness and high heat-resistance epoxy resin systems, which can also be used to produce epoxy resin adhesive. Main contents and conclusions of this dissertation are as follows:1. Soluble poly(ether ether ketone) and poly(ether ether ketone) have different effect on the gelation time of epoxy resins. The results indicate that gelation time increase with adding more PEEK, while gelation time reduced with adding more s-PEEK and then increased. FTIR is also used to analyze the effect of curing temperature and time on curing behaviour. The more s-PEEK is used, the harder for epoxy groups reacted throughly.By using DSC, the processing of curing for the EP systems were ascertained to be 80℃/1h+120℃/3h+150℃/2h. The curing activation energy of E-51/s-PEEK&composite epoxy/s-PEEK&E-51 are 50.77 kJ/mol,52.17 kJ/mol,50.53 kJ/mol, and the order of reaction n are 0.874,0.877and 0.862 respectively. As is showed above, the adding of s-PEEK and changing epoxy resin have no more important effect on the cunng process.2. Comparing to PEEK/EP, the mechanical properties of s-PEEK/EP are examined. The system exhibits superior mechanical index than the unmodified epoxy resin, and adding s-PEEK achieves to better properties. The maximum of tensile strength, elongation at the break, flexural strength, flexural modulus, impact strength and tensile shear strength get about 64.43Mpa,6.98%,60.93Mpa,2828.2MPa,44.62kJ/m2,39.5Mpa, respectively. At the same time, we also test the effect of curing condition and curing agent on parts of mechanical properties.3. The thermal strength at 100℃of composite epoxy resin increases with adding more PEEK into it, and the property of system containing s-PEEK is better. The change of thermal strength at 23℃,50℃,100℃, 150℃,180℃were also studied, and the thermal strength at low temperature is bigger when the system containing s-PEEK and TFE, while the system containing PEEK and AG-80 is bigger at high temperature. And the heat aging resistance and moisture heat aging of systems containing s-PEEK were also researched.4. The results of Dynamic mechanical thermal analysis(DMA) indicated that the cured blends clearly display only one maxima on the tanδcurves. The glass transition temperature (Tg) increased with the enhancement of s-PEEK content. When adding 25phr s-PEEK into epoxy system, Tg toughs to 179.61℃. Changing curing temperature and adding TFE have effect on the tanδcurves, also have only single apex while use of DDS have two apexes. Differential scanning calorimetry (DSC) is also used to analyze Tg of composite epoxy resins. TG test on epoxy resin systems including 3 different content of s-PEEK, the 50% gravity thermal loss temperature are 414.90℃,415.55℃and 423.32℃, which indicates that thermal stability enhanced with s-PEEK added into the epoxy resins.5. According to the results of SEM, DMA, DSC and impact properties, the toughening mechanism of two types of poly(ether ether ketone) modified epoxy resin was discussed. The toughening of PEEK relys on the cooperation effect of bridge-link anchor of dispersed phase, playing a leading role of shearing-bending of matrix. The toughening effect of s-PEEK exhibit more effective, which are ascribed to the contribution of semi-IPN in the epoxy resin systems.
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