Specialty polyurethane elastomers

A distillation process is sometimes used to produce pure MDI. However, about of the MDI output is sold in a polymeric form. Much of the MDI production is used in making polyurethane foam. However, significant quantities of the pure MDI are used in making specialty polyurethane elastomers. 

TDI (10a and 10b) is prepared from o-nitrotoluene, which is first nitrated to afford 1,4- and 1,5- dinitro isomers. These products are hydrogenated to the corresponding diamines, at 74 °C, over a palladium-on-carbon catalyst. This is the only major use of toluene diamines. On phosgenation, using chlorobenzene as solvent, at around 52 °C, the amines afford the diisocyanates. The TDI is used in the manufacture of flexible foams (upholstery, bedding, seat cushions, etc.), paints, surface coatings, elastomers and adhesives. 1,5-Diaminonaphthalene (13) is converted into naphthalene-1,5-diisocyanate (14) (Scheme 5), used in specialty polyurethanes. 

Elastocast, Castable polyurethane elastomer systems, BASF Corp., Urethanes Specialties Elastoflex, Flexible polyurethane systems, BASF Corp., Urethanes Specialties EUastoflex R, Semi-flexible polyurethane systems, BASF Corp., Urethanes Specialties EUastoflex TF, Thermoformable polyurethane foams, BASF Corp., Urethanes Specialties Elastoflex W, Hexible polyurethane foam systems, BASF Corp., Urethanes Specialties Elastofoam I, Rexible integral skin polyurethane systems, BASF Cap., Urethanes Specialties Elastofoam WB, Water-blow flexible integral skin PU systems, BASF Corp., Urethanes Specialties... 

Elastolit SR, Structural RIM polyurethanes, BASF Corp., Urethanes Specialties Elastollan, Thermoplastic polyurethane elastomers, BASF Corp., Urethanes Specialties Elastomag, Magnesium oxide, Morton International Inc., Morton Performance Chemicals... 

Rimpact, Polyurethane elastomer. Foam Molders Specialties... 

Among the contrarians, Bayer has had for historical reasons a different approach to the problem of remaining a well-rounded producer of chemicals. It has always been a leader in such specialty chemicals as plastics and rubber additives and supplies master batches through its subsidiary Rhein Chemie. Its polymers are mainly centered on synthetic elastomers and specialty plastics like polyurethanes and polycarbonates that Bayer itself develops. These are not subjected to the cutthroat competition that commodity thermoplastics are. Bayer has remained involved in aroma chemicals with a well-known subsidiary, Haarmann Reimer. In pharmaceuticals the company occupies an honorable rank, although in the future its management may want to separate that branch from the rest of its activities in preparation for further alliances. Like BASF, Bayer considers its agrochemical line as a core business. However, unlike BASF, it is less interested in integrating upstream production to oil raw... 

Polyurethane rubbers are a special type of PU elastomer. The PU rubbers are highly resistant to oil and fuel and have high abrasion resistance and tensile strength similar to PU elastomers. Polyurethane rubbers maintain their flexibility even at a temperature as low as -40° C and are thermally stable up to 125°C. Polyurethane rubbers have better mechanical strength and resist abrasion, ozone, and oil better than other specialty rubbers such as acrylates and nitrile butadiene. ... 

Priplast [Unichema Unichema France SA] Azelates or epoxizied oleate plasticizers for PVC, PVDC, PVAc, cellu-losics, specialty rubbers, nitroceOulose, polyvinylbutyral films polyester polyols for polyurethane foam, coatings, and thermoplastic elastomers. 

Blends of the commodity polymers with more specialty polymers are limited although many specific examples exist in the patent/open literature. In the design of polymer blends for specific application needs, countless opportunities can be envisioned. Examples may include PE/poly(s-caprolactone) (PCL) blends for biodegradable applications (proposed), polyolefin (PO)/poly(vinyl alcohol) (PVAL) blends for antistatic films, PO/silicone rubber blends for biomedical applications, PO/thermoplastic polyurethane TPU (or other thermoplastic elastomers) for applications similar to plasticized PVC, functionalized PO/thermoset blends. 

Most compounders use a combination of physical and chemical antiozonants and achieve excellent protection in this way. For more severe ozone-resistance problems, there are, of course, a number of specialty elastomers that are saturated and therefore completely ozone-resistant ethylene/propylene rubber, chlorinated and chlorosulfonated polyethylene, ethylene/vinyl acetate, ethylene/acrylic esters, butyl rubber, SEES, plasticized PVC, butyl acrylate copolymers, polyepichlorohydrin and copolymers, polyetherester block copolymer, polyurethane, and silicone. 

Polyurethane materials exist in a variety of forms including flexible or rigid foams, chemical resistant coatings, specialty adhesives and sealants, and elastomers. Most polyurethanes are thermoset materials they cannot be melted and reshaped as thermoplastic materials. Once the reactions have ceased the thermoset polyurethanes are cured and cannot be heat shaped without degradation. The thermal stability results from the croslinking degree of polymer chains (the crosslink density) and from the nature and frequency of repeating units within the polymer chains. 

Estaloc, Glass fiber-reinforced urethane elastomer, BFGoodrich Specialty Chemicals Estane, Polyurethane resins and compounds, BFGoodrich Specialty Chemicals Estoin, Polymer soluble dyes, Oariant Cotp., BU Additives... 

An annual total of approximately 9 billion pounds of MDI was produced worldwide in 2010, with oniy a relatively small quantity going into polyurethane specialty elastomers. 

DBEEA is used in compounds based on specialty elastomers such as NBR because it can impart very good low- and high-temperature properties to the compound. DBEEA is also used with compounds based on ACM, ECO, and polyurethanes. 

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