Synthesis of a soluble azomethine‐containing bisphenol and the properties of its modified epoxy thermosets

Abstract

A soluble bisphenol containing azomethine moiety and aromatic ether linkage, 2,2′‐bis {4‐[4‐(hydroxy) phenyliminomethylidene] phenoxyphenyl} propane (BHPP), was synthesized from the reaction of 4‐hydroxybenzaldehyde with 2,2′‐bis (4‐aminophenoxy phenyl) propane (BAPP) and characterized by IR, 1H NMR, 13C NMR, and elemental analysis. To improve the overall properties of epoxy/diamine thermoset, ternary‐curing systems combined BAPP/BHPP with diglycidyl ether of biphenyl A (DGEBA) were designed. It was found that the curing behavior and properties of the BAPP/DGEBA system changed dramatically due to the introduction of BHPP. The hybrid‐curing agents BAPP/BHPP exhibited more reactivity toward oxirane group than did BAPP. All the epoxy thermosets had high thermal properties, e.g., glass transition temperatures (Tgs) are between 145 and 170°C, 5% weight loss temperatures over 329°C, integral procedure decomposition temperature (IPDT) varied with 682–1085°C and good flame retardancy for their high limited oxygen index (LOI) values beyond 28.4. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Development of ricehusk ash reinforced bismaleimide toughened epoxy nanocomposites

“…The wide spread uses and properties of epoxy resin have been extensively studied by our research group for the past two decades (Dinakaran et al, 2003; Rajasekaran and Alagar, 2007; Premkumar et al, 2008; Ramesh et al, 2010; Selvaganapathi et al, 2010; Chandramohan and Alagar, 2011; Vengatesan et al, 2011; Kanimozhi et al, 2013; Prabunathan et al, 2013). In the present study an attempt has been made to form a covalent bond between organic polymers and inorganic components through coupling agent to enhance the compatibility of components involved (Farhadyar et al, 2005; Bagherzadeh and Mahdavi, 2007; Xinghong et al, 2007; Qingming et al, 2008; Balamurugan and Kannan, 2010; Sea-Fue et al, 2010). …”

Thermal properties and flame retardancy of novel epoxy based on phosphorus‐modified Schiff‐base

“…Utilizing a readily available phosphorus resource, phosphonate groups were successfully introduced into the molecule backbone of epoxy. Owing to the excellent rigidity of Schiff‐base CN imine group, the incorporations of the related groups were usually advantageous in terms of the thermal properties of epoxy resins 22, 23. This paper outlines the thermal properties and flame retardancy of the phosphorus‐modified epoxy thermosets.…”

Novel halogen-free flame retardant thermoset from a hybrid hexakis (methoxymethyl) melamine/phosphorus-containing epoxy resin cured with phenol formaldehyde novolac

“…Halogen-free flame-retardant epoxy resins are being developed and are expected to reduce the release of toxic substances during fire. By covalent incorporation of nitrogen [11,12,[15][16][17][18][19][20][21][22][23][24] and phosphorous [3, 4, 7-9, 13, 14, 22, 23, 26, 30] into the backbone of the epoxy resins, better flame retardancy can be achieved. Thereinto, it is a very effective way to improve the flame retardancy by introducing P and N elements together into the epoxy matrix.…”

“…In these P and N containing flame retardant systems, P is favourable to the formation of char structure while N is generally released as a non-flammable gas which can dilute air and absorb heat energy in combustion. However, complex synthesis of most reported nitrogen-containing epoxy resins or hardeners [19,21] is unfavourable to their application. Hexakis (alkoxymethyl) melamine (HMMM) is widely used as flame retardant for polymeric materials because it has high nitrogen content and low cost.…”