Flame retardance, liquid crystal

This volume is including information about thermal and thermooxidative degradation of polyolefine nanocomposites, modeling of catalytic complexes in the oxidation reactions, modeling the kinetics of moisture adsorption by natural and synthetic polymers, new trends, achievements and developments on the effects of beam radiation, structural behaviour of composite materials, comparative evaluation of antioxidants properties, synthesis, properties and application of polymeric composites and nanocomposites, photodegradation and light stabilization of polymers, wear resistant composite polymeric materials, some macrokinetic phenomena, transport phenomena in polymer matrix, liquid crystals, flammability of polymeric materials and new flame retardants. 

Known for many years, epoxy oligomers made from tetrabromobisphenol A are still used as the flame retardant in polycarbonates because they minimally affect the heat distortion temperature and even show a positive effect on impact strength. About 6—9 wt% of the epoxy oKgomer is required for achieving V-0 rating and a thermotropic liquid crystal polyester helps to improve melt flow, so that thin-waUed parts can be molded [38]. Antimony trioxide is not normally used in combination with halogen-containing additives in PC, because it causes loss of clarity. 

Liquid crystal polymers (LCP) are highly ordered crystalline aromatic polyesters with high mechanical strength. They are exceptionally inert, having very high thermal and chemical stability, are highly resistant to UV radiation and are inherently flame retardant and antistatic. 

Dow has produced a polycarbonate grade for liquid crystal display monitors, incorporating a silicone flame retardant. Formulations containing the silicone additive are said to have better impact strength and temperature resistance than those protected by phosphorus based flame retardants, and better heat and light stability than those containing brominated FRs. 

Many high-performance polymer fibres are used in filter media to meet various specific requirements in diverse filtration applications. Filters made from fluoropol-ymer (Polytetrafluoroethylene (PTFE), Polyvinylidene fluoride (PVDF), and Per-fluoroalkoxy alkane (PFA)) fibres, and membranes have inherent, chemical-resistant, and flame-retardant properties, and they are widely employed to filter aggressive chemicals and acids in the manufacture of wafers and microchips in the microelectronics industry. Ethylene ChloroTriFluoroEthylene (E-CTFE) melt blown fabrics have a unique ability to coalesce difficult liquids and can withstand the piranha effect in filtering ozone enriched ultrapure water. Polyphenylene sulfide (PPS) fibres are also chemical resistant, stand high temperature, and are suitable for making baghouse filters. Eilter media made from other high-performance polymer fibres, such as polyamide-imide, polyetherimide (PEI), Polyimide P84 fibre,polyetheretherke-tone, and liquid crystal polymers also appear in the filtration and separation market. 

New phosphorus containing polysulfones could be obtained by using different phosphorus containing diols in the classical synthesis of PSF (Scheme 6.4). Diols can contain phosphorus in main chain position or incorporate in a phenanthrene-type ring as side chain. These different phosphorus-containing diols form aromatic polyethers by polycondensation with dihalogen-substituted aromatic sulfones [48]. The chain structure of the polymer (aromatic or aliphatic) and the position of phosphorus in the chain influence the polymer properties (electroluminescence [49,50], flame retardancy [51], liquid crystal properties [52]). 

Santiclzer 2148 la a low-smoke, flame-retardant alkyl aryl phosphate ester plasticizer with very low volatility, excellent low-temperature performance and good softening efficiency. Molecular Weight Proprietary Phosphorus, % Proprietary Acidity (meq/100 gm max) 0.20 Appearance Clear, oily liquid Color (APHA) (Max) 200 Moisture (KF in Methanol) % max 0.10 Odor Essentially odorless Refractive Index ( 25C) 1.494-1.502 Specific Gravity (25/25C) 1.028-1.044 Density ( 25C) ca Ibs/gal 8.65 Crystallizing Point OC (32F)... 

Plastic containing brominated flame retardants Asbestos waste Cathode ray tubes CFC, HCFC, or MFCs Gas discharge lamps Liquid crystal displays -surface area >10 cm ... 

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