In this study, carboxyl-terminated poly(butylene adipate) (CTPBA) was synthesized, which was terminated with epoxy and used as a toughening agent to modify the epoxy resin, and the modified epoxy resin was cured at room temperature.

As a typical brittle material, epoxy resin cannot meet its application requirements in specific fields by only considering a single toughening method. In this paper, the effects of carboxyl-terminated polybutylene adipate (CTPBA) and zinc powder on the mechanical properties, adhesion properties, thermodynamic properties and medium resistance of epoxy resin were studied. A silane coupling agent (KH-550) was used to modify zinc powder. It was found that KH-550 could significantly improve the mechanical properties and bonding properties of epoxy resin, and the modification effect of flake zinc powder (f-Zn) was significantly better than that of spherical zinc powder (s-Zn). When the addition amount of f-Zn was 5 phr, the tensile shear strength and peel strength of the composites reached a maximum value of 13.16 MPa and 0.124 kN/m, respectively, which were 15.95% and 55% higher than those without filler. The tensile strength and impact strength reached a maximum value of 43.09 MPa and 7.09 kJ/m2, respectively, which were 40.54% and 91.11% higher than those without filler. This study provides scientific support for the preparation of f-Zn-modified epoxy resin.

A metal-organic framework (MOF) formed between Zn and p-hydroxybenzoic acid (PHBA) is synthesized using a solvothermal method. These Zn-PHBA nanorods, which are inexpensive and suitable for mass production, are added as a flame-retardant into vinyl resin (430 LV, a material used in marine composites). Data from cone calorimetric test demonstrates that adding the Zn-PHBA nanorods to 430 LV significantly improves flame retardation and smoke suppression. At a high Zn-PHBA content of 10.0 wt%, the limiting oxygen index of 430 LV increases from 19.5% to 28.5%, and the material reaches the V-0 rating in vertical burning tests (UL-94). Moreover, the tensile and impact strengths of 430 LV containing 10 wt% Zn-PHBA as flame-retardant do not deteriorate and are even slightly improved. This work demonstrates that this MOF synthesized by a simple and efficient method may be used to produce nanocomposites with excellent flame retardation and mechanical properties, while keeping the material cost sufficiently low for marine applications.