## 4 Conclusions  
In this paper, we synthesized bisphenol A dipropargyl ether and prepared blended resins by molar blending it with bisphenol AF-type di cyanate ester, bisphenol A-type di cyanate ester, and bisphenol E-type di cyanate ester, respectively, in a solution. We investigated the curing reactions and properties of the catalytically cured resin systems using copper acetylacetonate, manganese acetylacetonate, chromium acetylacetonate, and dibutyl ditin laurate as catalysts. The results demonstrated that the acetylacetone salts of transition metals and dibutyl ditin laurate effectively lowered the curing temperature of bisphenol AF-type di cyanate esters. Specifically, copper acetylacetonate, with a mass fraction of 0.2%, significantly reduced the curing temperature of bisphenol AF-type di cyanate esters to below 473 K. Furthermore, after the pre-polymerization of bisphenol A dipropargyl ether and equimolar blending with bisphenol AF-type di cyanate ester, bisphenol A-type di cyanate ester, and bisphenol E-type di cyanate ester, all three blended resins could be cured below 473 K under the catalysis of copper acetylacetonate. Among these, the blended resin of bisphenol A dipropargyl ether and bisphenol E-type di cyanate  
\begin{table}
\begin{tabular}{c c c c} \hline
**Catalytic Curing Hybrid Resins** & **T\({}_{\text{SF}}\)/K** & **Y\({}_{\text{eff}}\)/3k/\%** & **Y\({}_{\text{eff}}\)/3k/\%** \\ \hline BADPE/BADCy & 652.15 & 81.6 & 35.9 \\ BADPE/BEDCy & 652.15 & 85.5 & 37.9 \\ BADPE/BAFDCy & 647.15 & 88.6 & 0.7 \\ \hline \end{tabular}
\end{table}
Table 4: TGA test results of three hybrid resin cures in air.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Hybrid Resin** & **Bending** & **Bending** & **Impact** \\
**Casting Body** & **Strength/Mpa** & **Modulus/GPa** & **Strength/kJ-m\({}^{-2}\)** \\ \hline BADPE/BAFDCy & 92 \(\pm\) 2.11 & 3.6 \(\pm\) 0.22 & 15.9 \(\pm\) 0.82 \\ BADPE/BADCy & 79.7 \(\pm\) 2.41 & 4.1 \(\pm\) 0.11 & 12.2 \(\pm\) 1.24 \\ BADPE/BEDCy & 129.4 \(\pm\) 2.33 & 4.3 \(\pm\) 0.09 & 27.3 \(\pm\) 0.62 \\ \hline \end{tabular}
\end{table}
Table 5: Mechanical properties of cured resin blends of bisphenol A diethyl propynyl ether and cyanate ester.  
ester exhibited superior overall performance, featuring a residual rate of 38% in air at 873 K, as well as an impressive flexural strength (129.4 MPa), flexural modulus (4.3 GPa), and impact strength (27.3 kJ\(\cdot\)m\({}^{-2}\)).  
Our next steps will involve further investigations into a bisphenol A dipropargyl ether/bisphenol E-type di cyanate ester blended resin reinforced by carbon fiber. We will delve into the mechanical properties of the composites, their compatibility with liquid oxygen, and the catalytic curing of the blended resin. Carbon fiber-reinforced resin matrix composites are widely used mainly because of their light weight, high strength, good heat resistance, plasticity, and corrosion resistance. In aerospace and other fields, the use of carbon fiber-reinforced hybrid resin matrix composites can significantly improve the safety of their products, increase the quality of products, and play a good role in promoting the development of the industry.  
Methodology, C.L. and Z.L.; software, Y.H.; validation, F.L.; formal analysis, C.L. and X.Z.; investigation, Z.L. and Y.H.; resources, K.X.; data curation, K.X.; writing--original draft preparation, F.L.; writing--review and editing, Z.L. and C.L. All authors have read and agreed to the published version of the manuscript.  
The authors received financial support from the National Natural Science Foundation of China (No: U1837203).  
Not applicable.  
The authors thank the members of their research team for all their help in the process of testing, researching, and writing the thesis.  
Author [PERSON] was employed by Shanghai Composites Science & Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.