A bio-based hyperbranched flame retardant for epoxy resins

Effect of ethyl‐bridged diphenylphosphine oxide on flame retardancy and thermal properties of epoxy resin

“…However, there is a new absorption peak at 924 cm −1 , which can be attributed to the vibration absorption of the POPh bond. The POPh bond can be produced during the decomposition of HTP‐6123 at temperatures lower than 400°C, and further increases at temperatures higher than 450°C may be produced by the reaction of decomposing products of polyphosphate from the DOPO ring with other pyrolysis products (phenol or bisphenol) . From the absorbance analysis, it can be found that the amount of pyrolysis products of EP/HTP‐6123‐P‐0.9 is less than that of EP/HTP‐6123‐P‐0.9.…”

Improving the toughness of polycyanate ester by adding epoxy pre‐polymer with different molecular weights

“…First, in the PreEP/CE system, with the increase of PEA content, there are longer epoxy molecular chains (PreEP) in the system. These molecular chains are more likely to migrate at lower temperatures, [33,41,48] which is why the system's E' 182 C value (Figure 5b and Table 1) continues to decrease. Second, there are fewer ethylene oxide groups in PreEP, which decreases the chemical connection between the PreEP phase and the CE phase in the system.…”

“…This happens because the PreEP molecular chain was more likely to migrate at low temperatures to reduce T g1. [33,41,48] Meanwhile, the PreEP phase and the CE phase were chemically linked to reduce T g2 . Besides, the half-peak width of the PreEP/CE system was higher than that of CE and EP/CE, indicating that the molecular chain flexibility of PreEP/CE was higher than that of CE and EP/CE.…”

“…[27,30] Furthermore, an inferior toughening effect can be realized with a non-phase separated structure by simply blending CE with polymers like epoxy. [31][32][33][34][35][36] This is due to its excellent mechanical properties, its affordability, and the fact that it does not release small molecules. [33][34][35][36] The epoxy groups will react with the CE's triazine ring, hindering the formation of the phase-separated structure.…”

“…[31][32][33][34][35][36] This is due to its excellent mechanical properties, its affordability, and the fact that it does not release small molecules. [33][34][35][36] The epoxy groups will react with the CE's triazine ring, hindering the formation of the phase-separated structure. [10,32,37,38] Therefore, the toughening effect of cyanate resin modified by epoxy resin is greatly limited.…”