Tetrafunctional epoxy as an all‐purpose modifier for homopolymerized bisphenol A diglycidyl ether

In some applications, homopolymerized epoxies, which offer better biocompatibility and lower water absorption than amine‐ and anhydride‐cured epoxy, are more preferable; however, using homopolymerized epoxy as matrix in composites still remains a challenge. Herein, homopolymerized bisphenol A diglycidyl ether curing systems with simultaneously improved tensile strength, impact strength, and glass transition temperature (T_g) were achieved by addition of small amounts of tetra‐functional epoxies (TFTEs) with different spacer lengths. Effects of spacer length in TFTE on thermal and mechanical properties were investigated. Results indicated that TFTE with the longest spacer length shows the best mechanical performance. In addition, effects of TFTE loading on thermal and mechanical properties were discussed. Compared with neat bisphenol A diglycidyl ether, addition of 5% tetraglycidyl‐1,10‐bis(triphenylmethane) decane leads to simultaneous improvements in tensile strength, impact strength, and T_g. Effects of thermal cycling on the mechanical properties were also reported. Results suggest that the modified homopolymerized epoxy shows good performances and could be used as matrix materials and possibly in some dental applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46431.