Macromolecular modifications of poly(etherketoneketone) (PEKK) copolymer prepared from diphenyl ether (DPE), terephthalic acid (T) and isophthalic acid (I) with a T/I ratio of 60/40 have been investigated above its melting temperature by gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and rheological measurements to assess the evolution of PEKK matrix during composite consolidation step. We mainly focused in this study on anaerobic conditions, i.e. degradation under nitrogen or in lack of oxygen. During exposure, thermal degradation leads to an increase of weight average molar mass M_w and viscosity which is typical to crosslinking/branching mechanism as already observed for PEEK in the literature. However, thanks to GPC measurements, it appears that a chain scission mechanism occurs in the same time related to a constant number average molar mass M_n. Crosslinking kinetics are identified at several temperatures between 320 and 400 °C with rheological measurements from a kinetic scheme governing the crosslinking mechanism. At last, the influence of the crosslinking process on PEKK crystallization is investigated. The final crystallinity and crystallization kinetics decrease with crosslinking due to branching of macromolecular chains.

由二苯醚（DPE），对苯二甲酸（T）和间苯二甲酸（I）以60/40的T / I比制得的聚（醚酮酮）（PEKK）共聚物的大分子改性已通过凝胶渗透作用在其熔融温度之上进行了研究。色谱（GPC），差示扫描量热法（DSC）和流变学测量方法来评估PEKK基质在复合固结步骤中的演变。我们的研究主要集中在厌氧条件下，即在氮或缺氧条件下的降解。在暴露过程中，热降解导致重均摩尔质量M _w增加如在文献中对于PEEK已经观察到的那样，粘度和粘度对于交联/支化机理是典型的。然而，由于GPC的测量，似乎断链机理同时发生，与恒定的数均摩尔质量M _n有关。通过控制交联机理的动力学方案的流变学测量，可以在320至400°C的数个温度下确定交联动力学。最后，研究了交联过程对PEKK结晶的影响。由于大分子链的分支，最终的结晶度和结晶动力学随交联而降低。