Syntactic foam composites of epoxy‐allyl phenol‐bismaleimide ternary blend—Processing and properties

Abstract

Syntactic foams based on a reactive polymer blend of Epoxy-Allyl Phenol-Bismaleimide were processed using hollow glass microballoons. The effect of microballoon concentration on the mechanical and thermophysical properties of the foam composites was investigated. The mechanical properties, specific strength, coefficient of linear expansion, and density of the foam composites showed decreasing trend with increase in microballoon concentration whereas the specific heat showed a marginal increase. The temperature dependence of the thermophysical properties revealed an increase in coefficient of linear expansion, whereas the specific heat was more or less insensitive to the test tempera-ture. Syntactic foams of fixed filler loading (50% by weight) were processed using a blend of two types of microballoons of different shell thickness. The mechanical properties increased proportional to the concentration of the higher shell thickness microballoon. At moderate filler load microballoon breakage dominated the failure mode. The compositional dependency of the mechanical properties was corroborated by SEM analysis of the fracture surfaces.

Phenolic syntactic foams: Low-density composites for structural and thermostructural applications

“…They find extensive application in marine, aerospace, and automotive industries. 1 The hollow microspheres/microballoons employed in these light weight composites may be made of polymers, metals or ceramics. 1 The matrices employed may also be polymer, metal or ceramic.…”

“…1 The hollow microspheres/microballoons employed in these light weight composites may be made of polymers, metals or ceramics. 1 The matrices employed may also be polymer, metal or ceramic. Among the various matrix systems used, polymeric matrices have been the most commonly used.…”

“…Blends of polymers are also used in syntactic foams to impart specific properties to the composites. 1,5,6…”

Phenolic‐epoxy matrix curable by click chemistry—synthesis, curing, and syntactic foam composite properties

“…Novolac cured epoxy resin system constitutes an addition curable formulation. But they need high curing temperature as the phenol‐epoxy reaction is quite sluggish even on catalysis . In this background, we explored click chemistry for effecting the curing of novolac by reaction with epoxy.…”

Development and characterization of epoxy syntactic foam filled with epoxy hollow spheres

“…Moreover, the usage of syntactic foams as core material in sandwich structure applications ensures high rigidity and compressive strength of the sandwich structures compared to utilization of other polymeric foams [10]. Several studies on mechanical properties of syntactic foams [7,[11][12] and their sandwich structures can be found in numerous published literature [9,[13][14]. Syntactic foams can be defined as composite materials in which hollow microspheres, or other small hollow particles, are randomly dispersed in a matrix [15].…”