Flame-retardant finishes for polyester

Cyclic oligomeric phosphonates with the varying degrees of structural complexity (Structure 5.4) are also available in the market.25 They are widely used as flame-retardant finishes for polyester fabrics. After the phosphonate is applied from an aqueous solution, the fabric is heated to swell and soften the fibers, thus allowing the phosphonate to be absorbed and strongly held. It is also a useful retardant in polyester resins, polyurethanes, polycarbonates, polyamide-6, and in textile back coatings. A bicyclic pentaerythritol phosphate has been more recently introduced into the market for use in thermosets as well as for polyolefins (preferably, in combination with melamine or ammonium polyphosphate)... 

Another approach to durable flame retardant finishes for polyester is the use of highly brominated chemicals as topical finishes. One particularly useful material is hexabromocyclododecane (HBCD, Fig. 8.19). To achieve durable flame retardancy, fabric padded with 8 % of a dispersion of this water insoluble material must be heated above 190 °C or 375 °F to form a film of the flame retardant on the fibre surface."... 

Bajaj P, Chakrapani S, Jha NK. Flame retardant finishes for polyester/ceUulose blends an appraisal. /Afacromo/ Sci-Rev Macromol Chem Phys 1985 C25(2) 277—314. 

THPOH—Ammonia—Tris Finish. By far the most effective finish for polyester—cotton textiles was a system based on the THPOH—NH treatment of the cotton component either foUowed or preceded by the appUcation of Tris finish to the polyester component. This combined treatment appeared to be effective on almost any polyester—cotton blend. A large amount of fabric treated in this way was sold throughout the United States and much of the rest of the world. Shortly after the introduction of Tris finishing, Tris was found to be a carcinogen. Most of the Tris treated production was in children s sleepwear, and this created a situation in which almost aU chemical fire-retardant-treated textiles were unfairly condemned as dangerous. Manufacturers mshed to replace chemically treated textiles with products produced from inherently flame-resistant fibers. Nowhere was the impact more severe than in the children s sleepwear market. New, safer materials have been introduced to replace Tris. Thus far none has been as completely effective. 

Flame relardanls are used in smolder-resistant upholstery fabric, combination flame retardant-durable press performance, flame-retardant treatments for wool, thermoplastic fibers (Tris. decabromodiphenyl oxide-polyacrylate finishes. Antihlu/e 19. nylon finishes), polyester-cotton fiber blends (THPOH-ummonju-Tris finish, decabromodiphenyl oxide-polyacrylate finish. THPC-amide-polytv illy I bromide) finish, THPOH-NHi and Fyrol 76. LRC-UX) finish, phusphonium salt-urea precondcn-satej. cotton-wool blends, and core-yam fabric,... 

Uses Flame-retardant plasticizer for NBR elastomers, PVC (sheeting, coatings for apparel, upholstery, wall coverings, wire insulation, plastisols, adhesives), PVAc adhesives, acrylics., finished film or coated fabric applies., vinyl plastisols, ethyl cellulose, phenolics, PP, PS, NC, SBR and butyl rubbers, engineering resins, unsat. polyesters, alloys antiwear agent EP agent... 

Simultaneous dyeing and flame retardation of 100% polyester fabric has always been a commercially successful aim and while research has been undertaken in this area with reasonable levels of durability achieved, either in a dye bath or by thermosol process, potential commercial exploitation depends on the costs relative to the cost of using an inherently low flammable polyester. Currently in the UK, for example, Solvay (formerly Rhodia) market Amgard CU which is the same as the former Antiblaze IQ " for finishing polyester textiles based on the cyclic phosphonate structure where n=l ... 

Fabrics should be tested after a defined wash or durability test which, in the case of Part 7, for fabrics treated with a flame retardant, is a single specified wash cycle. Only so-called durable flame retardant finishes as described in Chapter 8 will pass such a wash cycle since semi-durable treatments are usually only resistant to dry cleaning or simple water soak tests specified in BS 5651 1989, for example. Fabrics containing inherently flame retardant fibres such as Hi-modified polyester (e.g. Trevira CS ), polyacrylics (e.g. modacryUcs such as Kanekaron ), and polypropylene do not require a prewash treatment prior to testing. 

The major finishes for polyester fibers include photoprotective agents and antioxidants, antistatic agents, soil release finishes, antipilling finishes, and flame retardant finishes. Many of these chemicals can be added to the polymer melt prior to spinning. The finishes can also be added topically during dyeing and finishing. 

Tris(2,3-dibromopropyl jphosphate (better known as Tris) was an ideal flame retardant for polyester and was used extensively for this purpose. Unfortunately, Tris was found to be mutagenic and a potential cancer-producing agent and had to be removed from the marketplace. As a result of the ensuing confusion, all topical flame retardant finishes have become suspect, and certain flammability requirements have been relaxed to allow polyester to pass the flammability test for children s sleepwear without further treatment. 

THPC—Amide—PoIy(vinyI bromide) Finish. A flame retardant based on THPC—amide plus poly(vinyl bromide) [25951-54-6] (143) has been reported suitable for use on 35/65, and perhaps on 50/50, polyester—cotton blends. It is appUed by the pad-dry-cure process, with curing at 150°C for about 3 min. A typical formulation contains 20% THPC, 3% disodium hydrogen phosphate, 6% urea, 3% trimethylolglycouril [496-46-8] and 12% poly(vinyl bromide) soUds. Approximately 20% add-on is required to impart flame retardancy to a 168 g/m 35/65 polyester—cotton fabric. Treated fabrics passed the FF 3-71 test. However, as far as can be determined, poly(vinyl bromide) is no longer commercially available. 

It has been shown that xanthan gum is an effective migration inhibitor for the application of water-soluble chemicals, leading to uniform distribution and more reproducible fixation [379]. Although this work was specifically concerned with the application of a soluble flame retardant to polyester, suitability for the application of reactive dyes or resin finishes is also claimed. 

Ozone is being investigated for shrinkage prevention (182). Wool and blends of wool, cotton, and polyester have been finished to provide improved flame-retardant, durable-press, and shrinkage properties (183,184). Fabrics of these types are often used for uniforms or protective clothing (185). 

Aramid fibers, i.e. polyamide textile fibers made from aromatic amines and dicar-boxylic acid [177] are similar to polyamide and polyester fibers and are highly heat resistant and flame retardant. Aramid fibers must be heat set by steaming before wet finishing and washed before dyeing for good leveling. 

A semi-durable flame retardant application especially suited for wool, wool/nylon, wool/polyester blends. Laundering will remove this finish. 

Uses Flame retardant for plastics (flexible PVC, plastisols, polyolefins), paints, textile finishes, rubber compds. (neoprene, S/B) UV stabilizer for ABS, epoxy, polyesters, PE, PP, flexible and rigid PVC, VDC Features Synergist in formulations contg. phosphorous compds. and/or... 

Properties Liq. m.w. 208.33 dec. 180 C Uses Crosslinking agent for elastomers, resins initiator for curing polyester resins finishing initiator for styrenics a synergist for some halogen-containing flame retardants polymer modifier... 

The specimen holder of an oxygen index apparatus can be coupled to a balance beam for continuous monitoring of the mass loss of the specimen during the combustion. Such an apparatus was used by Methven for studying polyester resins filled with alumina trihydrate and polyester fabrics finished with flame retardants. 

---