Specifications, polyamide resin

Polyamide Resins. Another class of polyamide resins, in addition to the Hquid resins used as epoxy hardeners, are the thermoplastic type, prepared generaHy by the condensation reaction of polyamines with polybasic fatty acids. These resins find use in certain hot-melt adhesives, coatings, and inks. Diamines, typicaHy EDA (233), are the principal amine reactant however, tri- and tetramines are sometimes used at low levels to achieve specific performance. 

Specific volume resistivity/T(-1) relation of a liquid epoxy/polyamide resin system... 

Modification of Engineering Resins Specific interaction of the phosphonium ionomer from Exxpro elastomer with selected engineering resins such as Polycarbonates(PC), Polyesters(PET), Polyacrylates(PAE), Polyamides(PA), Polyphenylene Oxide(PPO), and Acetals(PAc) can be utilized to compatibilize, impact modify or nucleate the above resin in blends with similar polymers. Typical examples are ... 

The flammability of polyamide fibres is usually reduced in the finishing process. Rigid yams are dressed by applying urea, thiourea, or melamine/formaldehyde resins. On the surface of flexible polyamide fibres, about 10 per cent of ammonium bromide is fixed by a urea/formaldehyde resin. Specific flame-retardant finishing is not usual. ... 

Epoxy resins themselves are not suitable for protective coatings because when pigmented and applied they dry to a hard, brittle film with very poor chemical resistance. When copolymerized with other resins, specifically with those of the amine or polyamide family, or with esterfied fatty acids, epoxy resins will form a durable protective coating. 

In addition to polyamide, lamination inks ordinarily contain modifiers such as polyketone resin, plasticizer, and wax to impart specific properties such as block resistance and increased bond strength. Because laminating inks are usually reverse-side printed and end-up sandwiched between films, gloss is not a primary requirement. Water-base laminating inks that will meet the U.S. EPA emission requirements and have the correct functional properties are currently under development. 

Thermoplastic polyamides are used in coatings to modify alkyd resins (qv) in thixotropic systems (238) and to plasticize nitroceUulose lacquers (239). DETA-taH oil fatty acid-based polyamides are suggested for use as corrosion inhibitors in alkyd paints (240). Printing inks for fiexo-gravure appHcation on certain paper, film and foil webs rely on EDA- and PDA-based polyamides for their specific performance (241). 

In dentistry, silicones are primarily used as dental-impression materials where chemical- and bioinertness are critical, and, thus, thoroughly evaluated.546 The development of a method for the detection of antibodies to silicones has been reviewed,547 as the search for novel silicone biomaterials continues. Thus, aromatic polyamide-silicone resins have been reviewed as a new class of biomaterials.548 In a short review, the comparison of silicones with their major competitor in biomaterials, polyurethanes, has been conducted.549 But silicones are also used in the modification of polyurethanes and other polymers via co-polymerization, formation of IPNs, blending, or functionalization by grafting, affecting both bulk and surface characteristics of the materials, as discussed in the recent reviews.550-552 A number of papers deal specifically with surface modification of silicones for medical applications, as described in a recent reference.555 The role of silicones in biodegradable polyurethane co-polymers,554 and in other hydrolytically degradable co-polymers,555 was recently studied. 

In comparing the different blends, the specific advantages of each type, as well as any potential overlap in performance with other type of blends have also been discussed. The fundamental advantage of polymer blends viz. their ability to combine cost-effectively the unique features of individual resins, is particularly illustrated in the discussion of crystalline/amorphous polymer blends, such as the polyamide and the polyester blends. Key to the success of many commercial blends, however, is in the selection of intrinsically complementing systems or in the development of effective compatibilization method. The use of reactive compatibilization techniques in commercial polymer blends has also been illustrated under the appropriate sections such as the polyamide blends. 

Floors ana walls of structures are obvious areas where epoxy systems may be utilized to prevent deterioration from abrasion and chemical attack. Such systems are now to be found in original specifications. VTall surfaces may be coated viith epoxy systems based on solid resins dissolved in solvents and hardened with polyamines and/or polyamides. Porous surfaces, such as concrete blocks, are first prepared viith fillers to provide a smooth surface for application of coatings. 

Of the halogenated organics, brominated aromatic compounds are the most extensively used. Decabromodiphenyl oxide or Saytex BT-93 is approved, but poly-(dibromophenylene oxide) is specifically recommended for polyamides. Brominated epoxy resins are also suitable flame-retardants for polyamides. The synergetic partner additive is antimony trioxide in most cases. 

Zinc borate can be used as a fire retardant in PVC, polyolefins, elastomers, polyamides, and epoxy resins. In hal( en-containing systems, it is used in conjunction with antimony oxide, while in halogen-free systems it is normally used in conjunction with other FRs such as aluminum trihydrate, magnesium hydroxide, or red phosphorus. In a small number of specific applications, zinc borate can be used alone. 

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