Immobilization of flame retardant onto silica nanoparticle surface and properties of epoxy resin filled with the flame retardant‐immobilized silica

Abstract

To prepare silica nanoparticle having flame retardant activity, the immobilization of flame retardant onto hyperbranched poly(amidoamine) (PAMAM)‐grafted silica was investigated. Grafting of PAMAM onto a silica surface was achieved in a solvent‐free dry‐system using PAMAM dendrimer synthesis methodology. The immobilization of bromine flame retardant, poly(2,2′,6,6′‐tetrabromobisphenol‐A) diglycidyl ether (PTBBA), was successfully achieved by the reaction of terminal amino groups of PAMAM‐grafted silica (Silica‐PAMAM) with epoxy groups of PTBBA. The immobilization of PTBBA was confirmed by FTIR and thermal decomposition GC‐MS. The amount of PTBBA immobilized onto Silica‐PAMAM was determined to be 60 wt %. PTBBA‐immobilized Silica‐PAMAM (Silica‐PAMAM‐PTBBA) was dispersed uniformly in a epoxy resin, and the epoxy resin was cured in the presence of hexamethylenediamine. Flame retardant activity of the epoxy resin filled with Silica‐PAMAM‐PTBBA was estimated by limiting oxygen index (LOI). The LOI of epoxy resin filled with Silica‐PAMAM‐PTBBA was higher than that filled with untreated silica and free PTBBA. It was confirmed that the flame retardant activity of epoxy resin was improved by the addition of the Silica‐PAMAM‐PTBBA. The elimination of PTBBA from the epoxy resin filled with Silica‐PAMAM‐PTBBA into boiling water was hardly observed by immobilization of PTBBA onto silica surface. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6145–6152, 2009

Pyrolysis of fire retardant anhydride-cured epoxy resins

“…To reduce blooming phenomena and deterioration in mechanical properties of TBPPA based ER the immobilization of flame retardant onto hyperbranched poly(amidoamine) (PAMAM)-grafted silica was investigated [8]. Zinc stannates and hydroxystannate are used components within synergistic fire retardant systems usually in conjunction with halogenated species in a number of polymers in substitution of antimony III oxide but they are nontoxic, smoke suppressant and specific in their synergistic activity [9].…”

Simultaneous improvements in flammability and mechanical toughening of epoxy resins through nano-silica addition

“…The layer forming at the surface then hinders the pyrolysis gases from migrating to the environment [18,20,21]. Nano-silica has been investigated in the past for providing improvements in flame retardancy [20][21][22][23][24][25][26][27]. The main flame retardant effects identified are the formation of a mass barrier for pyrolysis gases as well as an increased inert content reducing the amount pyrolysate available.…”

Dual-modality imaging with 99mTc and fluorescent indocyanine green using surface-modified silica nanoparticles for biopsy of the sentinel lymph node: an animal study

“…The particle size, specific surface area, and silanol group content were 12 nm, 200 m 2 /g, and 1.37 mmol/g, respectively [14]. The grafting of hyperbranched PAMAM (generation 3) onto the silica nanoparticle surface was achieved, as shown in Figure 1[15].…”

“…The percentage of PAMAM that grafted onto the silica surface was determined using a previously described equation [14]. The amino group content on the silica nanoparticle surface was determined by titration.…”