Flame retardant challenges for textiles and fibres: New chemistry versus innovatory solutions

Almost 50 years ago, the 1950-1960 period witnessed the development of the chemistry underlying most of today’s successful and durable flame retardant treatments for fibres and textiles. In today’s more critical markets in terms of environmental sustainability, chemical toxicological acceptability, performance and cost, many of these are now being questioned. “Are there potential replacements for established, durable formaldehyde-based flame retardants such as those based on tetrakis (hydroxylmethyl) phosphonium salt and alkylsubstituted, N-methylol phosphopropionamide chemistries for cellulosic textiles?” is an oftenasked question. “Can we produce char-forming polyester flame retardants?” and “Can we really produce effective halogen-free replacements for coatings and back-coated textiles?” are others. These questions are addressed initially as a historical review of research undertaken in the second half of the twentieth century which is the basis of most currently available, commercialised flame retardant fibres and textiles. Research reported during the first decade of the twenty first century and which primarily addresses the current issues of environmental sustainability and the search for alternative flame retardant solutions, the need to increase char-forming character in synthetic fibres and the current interest in nanotechnology is critically discussed. The possible roles of micro- and nano-surface treatments of fibre surfaces and their development using techniques such as plasma technology are also reviewed

Substantive intumescence from phosphorylated 1,3‐propanediol derivatives substituted on to cellulose

Cellulose flame retarded with an ammonia-cured, polycondensed tetrakis (hydroxymethyl) phosphonium-urea derivative (as Proban CC®,Rhodia) phosphorylated by cyclic 1,3-propanediol phosphoryl chloride or CPPC and cyclic 2,2-diethyl-1,3-propanediol phosphoryl chloride or CDPPC can give phosphorus levels up to 6.9%(w/w). Such high levels suggest up to 35.5% yields of reaction if the free secondary amine groups present in the cross-linked flame retardant and the C (6) primary hydroxyl groups are the assumed phosphorylation sites. The presence of substituted propanediol phosphonate moieties in the fibres significantly increases char formation above 400oC and scanning electron microscopy indicates that the char has an intumescent structure. The influence of chemical structure of the propanyl moeity to the reaction extent of the possible phosphorylation sites and the char formation mechanism during thermal pyrolysis of the modified samples are discussed

Polymer degradation and the matching of FR chemistry to degradation

In fires, polymeric materials are consumed by flaming combustion which is a gas phase process. Thus the polymer must degrade to yield volatile combustible species to fuel the conflagration. To begin, this chapter first considers the various processes by which pure polymer systems degrade. Then any influence by which the presence of oxygen can affect these processes is discussed. The different structures of the various polymer types influence the end consequence of any decomposition and this will affect the resistance, if any, to combustion. At this point the polymer combustion cycle will be described