ABSTRACT This work investigates the synthesis and characterisation of macrocyclic oligomers (MCO) from 4, 4’-difluoro benzophenone and catechol, their ring opening polymerisation, fabrication into carbon fibre reinforced composite materials and depolymerisation. The MCOs are polymerised using Caesium fluoride at a variety of temperatures, times, and catalyst concentrations to produce ortho polyaryletherketone polymers (oPAEK) of varying glass transition temperature (Tg) and molecular weight. A dimer formed during synthesis which does not polymerise is removed enabling a more convenient synthesis using lower temperature and catalyst concentration. The first carbon fibre composite of oPAEK fabricated using in-situ ring opening polymerisation methods is therefore presented with and without MCO dimer. Composites made without dimer formed are able fabricated at 10 °C lower temperature than the corresponding MCO containing dimer and have improved thermal and mechanical properties. Depolymerisation of the MCO and the re-emergence of cyclic structures is reported, highlighting the reversible nature of the chemistry. The results presented here provide important guidance on the future development of in-situ polymerisation of high performance thermoplastic composites.

中文翻译：

---

通过原位开环聚合制备聚芳醚酮 (PAEK) 热塑性复合材料

摘要 这项工作研究了 4, 4'-二氟二苯甲酮和邻苯二酚的大环低聚物 (MCO) 的合成和表征、它们的开环聚合、制造成碳纤维增强复合材料和解聚。MCO 使用氟化铯在各种温度、时间和催化剂浓度下聚合，以生产具有不同玻璃化转变温度 (Tg) 和分子量的邻聚芳醚酮聚合物 (oPAEK)。合成过程中形成的未聚合的二聚体被去除，从而能够使用较低的温度和催化剂浓度进行更方便的合成。因此，第一个使用原位开环聚合方法制造的 oPAEK 碳纤维复合材料呈现有和没有 MCO 二聚体。没有形成二聚体的复合材料能够在比相应的含有二聚体的 MCO 低 10°C 的温度下制造，并且具有改进的热和机械性能。报道了 MCO 的解聚和环状结构的重新出现，突出了化学的可逆性质。这里介绍的结果为高性能热塑性复合材料原位聚合的未来发展提供了重要的指导。