Effects of a composite flame retardant system on the flame retardancy and mechanical performance of epoxy resin adhesive

Abstract

A flame‐retarded epoxy resin (ER) adhesive with strong flame retardancy and adhesion performance was prepared. The coated ammonium polyphosphate (MFAPP), melamine (MEL), and organic montmorillonite (OMMT) were mixed to prepare a composite flame retardant. It was subsequently blended with a toughened ER thoroughly and then the mixture was cured with polyamide. The resultant ER adhesive thermosets achieved UL‐94 V‐0 rating during vertical burning test, and the limiting oxygen index value was as high as 31.6%. The shear strength of the ER adhesive was 27.9 MPa when 25 wt% MFAPP/MEL/OMMT was introduced. Compared with the pure adhesive, the flame retardant epoxy adhesive maintained outstanding adhesion performance because of the good compatibility between the composite flame retardant additives and the toughened ER adhesive. Cone calorimetry tests indicated that the release of heat and smoke were obviously declined with the incorporation of the composite flame retardant system in comparison to pure ER adhesive thermoset. The investigation of flame retardant mechanism revealed that the composite MFAPP/MEL/OMMT flame retardant system stimulated the generation of highly expanded, integral, and strong char layer and the formed char layer exerted superior insulation effect during combusiton. The present work provided an alternative approach to prepare flame retardant ER adhesive with the similar excellent adhesive performance.

Fire impact on mechanically failed graphite/epoxy composites

“…The effects of different material systems, flame‐retardants, ply thickness, and fire exposure durations on thermal damage development and char/soot formation in initially undamaged composite laminates are well characterized. [ 13–33 ] For example, Vieille et al [ 34 ] assessed the residual moduli and strengths of 8‐ply unidirectional and quasi‐isotropic carbon fiber/polyether ketone ketone (C/PEKK) thermoplastic composite laminates subjected to fire testing with kerosene fuel at a temperature of 1100°C. After 15 min flame exposure, unidirectional C/PEKK laminates experienced 40% and 60% reductions in modulus and strength, respectively.…”

Thermally conductive and mechanically strengthened bio‐epoxy/boron nitride nanocomposites: The effects of particle size, shape, and combination

“…Since commercial epoxy resins are not sustainable, a great deal of effort has been recently directed toward synthesis of bio-epoxy from plant oils. [9][10][11][12] In recent years, several aspects of bio-epoxy resins and their composites with micro-and nanomaterials have been studied, among which are thermal, [13][14][15] mechanical, anti-corrosion, [16][17][18] and flame retardant [19][20][21] properties. Nevertheless, thermal and mechanical properties of green epoxy are not principally comparable with the counterparts based on petroleumbased epoxy systems, necessitating excessive modifications of bulk and surface properties of bio-epoxy resins.…”

Use of a combination of phosphorous‐containing epoxy resin and silica fillers for development of flame retardant thermoset polymer composites

“…[1][2][3][4][5] However, a major drawback of epoxy resin based composites (polymer composites in general) is the poor flame resistance which restricts their use for many civil and defense applications (such as naval and aerospace), which requires extremely high flame resistance. [6] Although epoxy-based products with UL-94 V-0 rating can be made by using halogen-based flame retardant (FR) materials, use of such FRs are restricted environmentally due to generation of toxic, and corrosive gases. [7][8][9] Phosphorous based FRs have been proved to be a suitable alternative.…”