Smart Collaborative Toughening Effects of Eu ³⁺ /Tb ³⁺ @ <scp>uCNTs</scp> and Phenolphthalein Polyether Sulfone on Dicyanate Ester of Bisphenol F Composites

ABSTRACT Cyanate ester resin (CER) is an excellent thermosetting polymer. However, its brittleness and poor mechanical properties limit its application. The innovation of this work lies in the smart collaborative toughening effects of Eu 3+ /Tb 3+ @uCNTs working together with phenolphthalein polyether sulfone (marked as PES‐C) on dicyanate ester of bisphenol F. Tb 3+ ‐complex enhances Eu 3+ @uCNT‐effects, and the cooperation of PES‐C together with Eu 3+ ‐Tb 3+ @uCNTs (marked as ET‐uC) functions strongly to increase flexural, tensile, and impact strengths by 209%, 120%, and 286%, respectively. When additions of ET‐uC ratio at 0.6 wt% and PES‐C ratio at 15% to CER. At the same time, we can get more multiple enhancing effects can be observed as below. The introduction of ET‐uC reduces the curing temperature of the composite material from 342°C to 271°C. At the same time, the mass loss rate decreased from 87% to 55%. The intensity of luminescent CER/ET‐uC/PES‐C is much stronger compared to CER/ET‐C/PES‐C. If the curing temperature is 250°C, the luminescence lifetimes of CER/ET‐C/PES‐C and CER/ET‐uC/PES‐C become 411.23 and 731.91 μs, respectively. These strong data confirm that our strategy of ET‐uC collaborating with the linear thermal stable polymer of PES‐C functions has generated the breakthrough to improve the comprehensive properties of CER.