With improved flammability characteristics

WHANG PEARCE Polymers with Improved Flammability Characteristics 267... 

Polyimide and Melamine. These are both low density, essentially open-cell foams used as pipe insulations, particularly those involved with fluids operating at temperatures up to 530 K. Because these foams operate at higher temperatures and have improved flammability characteristics compared to other foams, they are also used for some aircraft and marine applications. 

ABS foam provides properties that include impact, heat, and chemical resistance low mold shrinkage rates good long-term dimensional stability and platability. Improved flammability characteristics are possible either by alloying (blending) with PVC or polycarbonate, or by... 

This present English edition is not a direct translation of the Hungarian version. It has been thoroughly revised, principally because of the continuing rapid development of plastics. A couple of years is enough for the manufacture of a range of novel resins and products with markedly improved flammability characteristics. Brand-new concepts and products have appeared in the interval since the Hungarian edition was published, so that some chapters had to be completely re-written. The other chapters have also been carefully revised and supplemented as necessary. 

Parker et al. (30) reported the synthesis of phosphorous containing bismaleimides and demonstrated their outstanding non-flammability characteristics. Graphite fabric composites prepared from such P-containing BMI as a matrix resin show a LOI of 100 and an anaerobic char yield of 88% at 700 °C. Other P-containing BMI have recently been synthesized (31) for example, bis(3-maleimidophenoxy-4-phenyl)phenyl phosphine oxide (Figure 8) has been tested as a composite matrix resin with the aim of improving the fibre/resin interfacial adhesion. 

While JPS COMPOUND 150 is designed to have low flammability characteristics, it may also be compounded with other products for improved properties. 

In-depth physical examinations of new composite component designs for aircraft interiors have contributed to the need for improved materials, as well as upgraded flammability testing. For example, the standard Bunsen burner test did not adequately determine the flammability characteristics of medium-sized composite parts when exposed to a hidden heat source that might represent an in-flight fire threat. Industry leaders are working with the FAA to develop foam... 

Acrylate and methacrylate polymers are flame-retarded mainly by phosphorus compounds. Mixing monomeric methyl methacrylate with 8 per cent of phosphoric acid coupled with the initiator improves the flammability characteristics of the polymeric product. 

Chlorinated elastomers (polychloroprene, sulphochlorinated polyethylene, chlorinated polyethylene) have fairly good flammability characteristics. Further improvement can be achieved with alumina trihydrate or antimony trioxide. Halogenated phosphoric esters may be applied as plasticizers. 

Flame retardants may be incorporated as additives in particulate or coating form. They may be halogenated or non-halogenated. Their use must be considered in conjunction with their effect on mechanical properties, especially for durability. There is a need to match all the flammability characteristics, ignitability, heat development, smoke and toxicity and to ensure continued structural integrity. Some fire retardants may improve one of these fire performance characteristics at the expense of others. 

Secondary prevention and mitigation, by themselves, are unable to eliminate the risk of serious or catastrophic chemical accidents, although improved process safety management can reduce their probability and severity. Most chemical production involves transformation processes, which are inherently complex and tightly coupled. Normal accidents are an unavoidable risk of systems with these characteristics [11]. However, the risk of serious, or catastrophic, consequences need not be. Specific industries use many different processes. In many cases, alternative chemical processes exist which completely or almost completely eliminate the use of highly toxic, volatile, or flammable chemicals [12]. 

Oparex 15 calcined calcium sulphate (Yesos Ibericos) was evaluated as a filler in plasticised PVC cable insulation compounds in comparison with two grades of calcium carbonate. Improvements were observed in tensile, electrical and low temperature properties, flammability and heat ageing characteristics and chemical resistance for calcium sulphate filled compounds, while no significant differences in water absorption and hydrolysis were noted. Studies of rheological properties showed improved processability in mixing and extrusion trials. URALITA... 

Aluminum chloride hydrate is used in textile finishing to impart crease recovery and nonyeUowing properties to cotton (qv) fabrics, antistatic characteristics to polyester, polymide, and acrylic fabrics, and to improve the flammability rating of nylon (see Textiles). Dye-bleeding of printed textile may be blocked (17) by treatment with aluminum chloride and zinc acetate, Zn(02CCH2)2j followed by solubilizing with ethylenediamine tetraacetic acid, and washing from the fabric. 

As with other polymers and resins, the modification of epoxy resins eliminates a number of disadvantages including brittleness, low thermal stability and high flammability to give the required properties for end applications. Considerable effort has therefore been made to improve the thermal and mechanical properties of vegetable oil-based epoxy resins. These may be grafted or blended with other flexible resins such as polyester, polyacrylate and polyurethane to improve their flexibility and other performance characteristics. 

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