Advances in addition-cure phenolic resins

An overview of the recent literature on combustion and flame-retardancy of epoxy resins is presented. A brief overview of the structures of cured epoxy resins is also presented as a background for better understanding of the thermal decomposition and combustion phenomena. The literature sources were mostly taken from the publications of 1995 and later; however, for basic descriptions of the structural and thermal decomposition principles, older publications are also cited. New developments in flame-retardant additives, epoxy monomers and curing agents are described. It is shown that the main attention in recent years has been focused on phosphorus-containing epoxy monomers and epoxy resins. Silicon-containing or nitrogen-containing products and inorganic additives remain of great interest as supplementary materials to phosphorus flame-retardants. Copyright © 2004 Society of Chemical Industry

Thermal decomposition, combustion and flame-retardancy of epoxy resins—a review of the recent literature

Thermo-mechanical characterization of fumed silica-epoxy nanocomposites

Flame retardant novolac–bisphthalonitrile structural thermosets

This work has been mainly focused on the development and optimization of the processing methodology to produce epoxy modified phenolic foams. This study analyzes the relation between the composition and the structure as well as the mechanical and flammability performance of epoxy-phenolic (E-P)-based foams. Phenolic foams modified with different types and compositions of epoxy resin were successfully synthesized and characterized, showing uniform pore structure. Two epoxy resins were used for this approach. One is regular diglycidyl ether of bisphenol A (Epon 826) type and the other is a brominated bisphenol A (DER 542), which has halogen groups in the structure to improve the flammability properties of the resulting foams. Cone calorimeter (ASTM E 1354) was used to measure the heat release rate, the time to ignition, and other flammability properties of the E-P foams with different types of epoxy resins, under well-controlled combustion conditions. The mechanical performance of the system was studied and compared with competing foams, such us phenolic, epoxy, and polyurethanes, in aspects of compression, friability, and shear performances. Compared with conventional phenolic foams, E-P foams exhibit significant improvement in mechanical performance, lower friability and similar resistance to flame. These results demonstrate the potential of the E-P foam as a flame resistant and high performance core material for sandwich structure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1399–1407, 2007

Flammability properties and mechanical performance of epoxy modified phenolic foams

Structure–property relationships of void-free phenolic–epoxy matrix materials

Tough, void-free, flame retardant phenolic matrix materials

To address the insolubility problem of polyketones, we used an approach to high molecular weight wholly aromatic polyketones without ether linkages via soluble precursors derived from isophthaldehyde-based bis(aminonitrile)s. Polymerization of bis(α-aminonitrile)s with activated dihalides using NaH as base in DMF yielded soluble, high molecular weight poly(aminonitrile)s, which were hydrolyzed in acidic conditions to produce the corresponding aromatic polyketones without ether linkages or alkyl substituents in the polymeric backbones. These polyketones displayed excellent thermal properties and solvent resistance. For the synthesis of poly(aminonitrile)s and polyketones containing ether linkages in the polymeric backbone, only low to medium molecular weight polymers were obtained. Model studies proved that the carbanions of the aminonitriles reacted with ether linkages to form more stable phenoxide anions and cause the termination of the polymerization.

A Polyketone Synthesis Involving Nucleophilic Substitution via Carbanions Derived from Bis(α-aminonitrile)s. 4. Aromatic Poly(ether ketone)s

Latent nucleophilic initiators for melt processing phenolic–epoxy matrix composites

Fiber reinforced thermosetting matrix materials are advantageously created using fibers that are coated with a coating containing a nucleophilic initiator or have a surface treatment which creates a nucleophilic initiator on the surface. The fibers are combined with the thermosetting matrix materials just before curing of the matrix material is desired. These fibers and this methodology avoid premature curing, allow higher levels of initiator to be used to ensure rapid cure, and allow the thermosetting matrix materials to be heated to reduce viscosity.

C.S. Tyberg

Papers

Structure–property relationships of void-free phenolic–epoxy matrix materials

Tough, void-free, flame retardant phenolic matrix materials

A Polyketone Synthesis Involving Nucleophilic Substitution via Carbanions Derived from Bis(α-aminonitrile)s. 4. Aromatic Poly(ether ketone)s

Latent nucleophilic initiators for melt processing phenolic–epoxy matrix composites

Fiber materials for manufacturing fiber reinforced phenolic composites and adhesives with nucleophilic initiators positioned on the fiber surfaces