▎ 摘　　要

Fire hazards have seriously hindered the commercial application of unsaturated polyester resin (UPR), and polymer inorganic nanosheet nanocomposites hold great promise in improving their flame-retardant properties. Herein, the hierarchical structured Cu2O-TiO2-GO nanosheets were synthesized and characterized by XRD, Raman, TEM and XPS. Then Cu2O-TiO2-GO nanosheets were incorporated into UPR matrix to obtain flame-retardant UPR nanocomposite. Incorporation of 2 wt%Cu2O-TiO2-GO nanosheets into UPR matrix resulted in an obvious reduction in PHRR and THR by 29.7 and 19.1%. TG-IR-MS results revealed that toxic pyrolysis gas such as benzene, CO and aromatic compounds greatly were decreased. In addition, RIIR spectra demonstrated the limited influence of Cu2O-TiO2-GO nanosheets on thermal degradation of UPR matrix, and SEM images of char residues showed that Cu2O-TiO2-GO nanosheets could improve their compactness. Based on the analysis of gaseous and condensed phase, a plausible flame-retardant mechanism was hypothesized to elaborate how Cu2O-TiO2-GO nanosheets work inside the flaming UPR nanocomposite. This innovative idea may be expanded to other polymer system and open a new door to develop polymeric nanocomposites with high performance. (C) 2016 Elsevier B.V. All rights reserved.