Heat-stabilisation of polyphenylene oxide solns. - to prevent viscosity loss, by adding (in)organic inhibitor base pref. combined with chelating agent

摘要

Polyphenylene oxide solns., prepd. esp. by a Cu/amine-catalysed polymerisation reaction, are heat-stabilised by adding an organic or inorganic base inhibitor, (A), partic. NaOH. (A)-concn., w.r.t. polymer, can be 0.1-10 (0.5-2) wt.%. (A) can be used together with an organic chelating cpd., (B), pref. ethylene diamine tetra-acetic acid. Mol. ratio (B) : Cu may be 1 : 1 to 3 : 1. (A)-addn. prevents oxidative degradation resulting in intrinsic viscosity losses on heating the solns. e.g. during centrifuging, concn. and hydrogenation.