Dicyanate ester–polyetherimide semi‐interpenetrating polymer networks. II. Effects of morphology on the fracture toughness and mechanical properties

Abstract

A high temperature thermosetting bisphenol-A dicyanate (BADCy) was modified with polyetherimide (PEI) at various compositions. The effects of the morphology of the blends on the fracture toughness and mechanical properties were investigated. For this purpose, fracture, flexural, and compression tests were carried out. The fracture surfaces of the broken specimens were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The morphology was controlled by changing the curing conditions and PEI content. A good correlation between fracture properties and microstructural features of the mixtures has been observed. The phaseinverted morphologies showed the highest fracture toughness, which was further increased by increasing the cure temperature. The mechanical properties of the matrix (modulus, yield strength) were not affected by the addition of the thermoplastic. Fracture energy values show similar trends for the different mechanical tests performed.

Curing of dicyanate ester/epoxy copolymers modified with polysiloxane and butadiene-acrylonitrile rubbers

“…• Copolymerization with epoxy (EP) resin • Blending CE resin with thermoplastic resins, for example polysulfone [5,6], polyarylate [7], poly(ether imide) [8], polycarbone, polyamide and so on • Application of reactive elastomers [9,10].…”

Evaluation of fiber surface treatment and toughening of thermoset matrix on the interfacial behaviour of carbon fiber-reinforced cyanate matrix composites

“…Nevertheless, although cyanate ester resins are known to be relatively tough compared with other thermosetting matrices, some applications require improved fracture resistance [4]. Thus, several attempts have been made to improve the toughness of cyanate ester by adding elastomers or thermoplastics [5][6][7][8][9][10][11][12]. Traditionally, the most successful method has been the addition of a suitable elastomer to the uncured resin [2,[5][6][7][8].…”

Viscoelastic properties and morphology of dicyanate ester/epoxy co-polymers modified with polysiloxane and butadiene–acrylonitrile rubbers

“…• Copolymerization with epoxy resin [1,[5][6][7] • Blending cyanate ester resin with thermoplastic resins, for example polysulfone [8,9], polyarylate [10], poly(ether imide), polycarbonate, polyamide [11] • Application of reactive elastomers [12,13].…”

“…In recent years, high-performance thermoplastics have been used to modify thermosetting resins such as PES, PEI, PEEK, ABS, etc., because of their high modulus and glass transition temperatures [8,9,11,20]. The incorporation of thermoplastics, initially miscible in epoxy resin and creating second phase during the epoxy-hardener curing reaction, leads to toughness improved polymer networks.…”