POLYMERIC FLAME

Abstract In this paper the synthesis, properties and applications of poly(organophos-phazenes) have been highlighted. Five different classes of macromolecules have been described, i.e. phosphazene fluoroelastomers, aryloxy-substituted polymeric flame-retardants, alkoxy-substituted phosphazene electric conductors, biomaterials and photo-inert and/or photo-active phosphazene derivatives. Perspectives of future developments in this field are briefly discussed. 

It was observed that brominated phosphate blends easily into various resins in a single or twin screw extruder. Compounding rates also are increased. It has been assumed that this is partly due to its high degree of solubility in aromatic solvent. This is in contrast with the polymeric flame retardants which are more difficult to incorporate or compound into various resins. 

A study was conducted in a Brabender Plastic-Corder. Brominated phosphate was compared with the polymeric flame retardants brominated... 

When the polymeric flame retardants are added In Increments, the viscosity increases to a point and then decreases and plateaus as the original viscosity or at a higher viscosity. When bromlnated phosphate is added in increments, the viscosity decreases immediately and then plateaus, at a lower viscosity than the starting viscosity. 

An Introduction to Polymeric Flame Retardancy, Its Role in Materials Science, and the Current State of the Field... 

Liu, W., Chen, D.Q., Wang, Y.Z., Wang, D.Y., and Qu, M.H. 2007. Char-forming mechanism of a novel polymeric flame retardant with char agent. Polym. Deg. Stab. 92 1046-1052. 

Trade names of two polymeric flame retardants have been reported in the technical literature Fire Guard 7500 (159, Sankyo Organic Chemicals, Co), a functionalized oligocarbonate for ABS prepared from 4,4 -isopropylidenebis(di-bromophenol) and FR 1025, poly(pentabromobenzyl acrylate) (76, Technion) [68]. 

Polymeric flame-retardant systems are introduced for better performance and specifically for better environmental care. They include ... 

Properties Wh. to off-wh. powd. insol. in common org. soivs. dens. 2.05 m.p. 190-220 C Toxicology LD50 (oral, rat) > 5000 mg/kg mildly Irritating to eyes and skin Uses Polymeric flame retardant for engineering thermoplastics, PET, PBT, nylon, PP, and PS Manuf./Distrib. Dead Sea Bromine http //WWW. dsbg. com... 

Uses Reactive intermediate for phenol-based reactions reactive flame retardant for phenolics, PC, epoxies antifungal agent wood preservative chemical intermediate for polymeric flame retardants Manuf./Distrib. Aldrich http //www.sigma-aldrich.com, AmeriBrom http //www.ameribrom.com, Fluka http //www.sigma-aidrich.com. Great Lakes http //www.greatiakeschem. com, M orre-Tec Ind. http //www.morretec.com Ocean Chems. 

Poly (ethylene terephthalate) (PET) was first introduced as a synthetic fibre when flameretarded by grafting with bromostyrene. Later PET and poly(butylene terephthalate) (PBT) emerged as engineering plastics, so that their more effective flame-retardance became of crucial importance. Diphenyls and diphenyl oxides at different degrees of bromination as well as brominated polymeric flame-retardants have been proposed (e.g. PBB-PA, Dead Sea PO 64 P, Great Lakes.) ... 

Ethenylidenebis(phosphonic acid) 1 and its esters have found utility as sequestering agents, in the development of polymeric flame retardants, and in certain pharmaceutical appheations. Ethenylidenebis(phosphonic acid) is prepared via the thermal dehydration of tetrasodium (l-hydroxyethylidene)bis(phosphonate) [165], Disadvantages of this time-consuming process include the need for precise control of temperature during the dehydration. 

Generally, however, the incorporation as additive of a phosphorus-containing polymer appears to be a valuable approach to impart flame retardancy to a polymer matrix. Chang et al. have synthesized a phosphorus-containing polymeric flame retardant. The phosphorus content in the polymeric flame retardant was 13.9 wt%. The LOI increased from 20.4 to 35.4% when the polymeric flame retardant was incorporated into the epojgr resin at a content of 8 wt%. The UL-94 rating was VO, with only 0.7 wt% of phosphorus. Similar results were found for other polymer matrices (PET and unsaturated polyester). 

Although certain cellulose esters, such as the ammonium salt of phospho-rylated cotton and cellulose phosphate [9015-14-9], are flame-resistant, the attachment of most currently used durable polymeric flame retardants for cotton is through ether linkage to the cellulose at a relatively low degree of substitution (DS). Nondurable flame retardants based on liquid-or vapor-phase applications of boric acid [10043-35-3] or methyl borate [121-43-7] are used in treatment of cotton batting for upholstery, bedding, and automotive cushions (112-114). Cotton carpet materials will pass the U.S. Consumer Product Safety Commission (CPSC) federal flammability test for carpets (16 CFR1630) when cross-hnked with polycarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid or citric acid with sodium phosphate, sodium hypophosphite, sodium bicarbonate, or sodium carbonate catalysis (115). 

Some specific recent applications of the chromatography-mass spectrometry technique to various types of polymers include the following PE [130, 131], poly(l-octene), poly(l-decene), poly(l-dodecene) and 1-octene-l-decene-l-dodecene terpolymer [132], chlorinated polyethylene [133], polyolefins [134,135], acrylic acid, methacrylic acid copolymers [136, 137], polyacrylate [138], styrene-butadiene and other rubbers [139-141], nitrile rubber [142], natural rubbers [143,144], chlorinated natural rubber [145,146], polychloroprene [147], PVC [148-150], silicones [151,152], polycarbonates (PC) [153], styrene-isoprene copolymers [154], substituted PS [155], polypropylene carbonate [156], ethylene-vinyl acetate copolymer [157], Nylon 6,6 [158], polyisopropenyl cyclohexane-a-methylstyrene copolymers [195], cresol-novolac epoxy resins [160], polymeric flame retardants [161], poly(4-N-alkylstyrenes) [162], pol)winyl pyrrolidone [31,163], vinyl pyrrolidone-methacryloxysilicone copolymers [164], polybutylcyanoacrylate [165], polysulfide copolymers [1669], poly(diethyl-2-methacryloxy) ethyl phosphate [167, 168], ethane-carbon monoxide copolymers [169], polyetherimide [170], and bisphenol-A [171]. 

High Molecular Weight or Polymeric Flame Retardants... 

Attempts have been made to synthesize higher molecular weight or polymeric flame retardants containing halogen or/and phosphorus or to introduce these elements by copolymerization. Chlorinated PE and chloro-sulfonated PE are selected for flame retardant uses largely because their chlorine content is high. 

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