Polyurethane polymer

PROPENE The major use of propene is in the produc tion of polypropylene Two other propene derived organic chemicals acrylonitrile and propylene oxide are also starting materials for polymer synthesis Acrylonitrile is used to make acrylic fibers (see Table 6 5) and propylene oxide is one component in the preparation of polyurethane polymers Cumene itself has no direct uses but rather serves as the starting material in a process that yields two valuable indus trial chemicals acetone and phenol... 

Addition Polymers. The most commonly referenced reaction of isocyanates iavolves their addition to polyhydroxyl, polyamine, or polycarboxyhc acid compounds to yield addition polymers. Due to the wide diversity of raw material characteristics and the broad range of functionahty, polyurethane polymers having a wide range of processiag and performance characteristics are available. 

Isocyanates can be characterized using a strong absorption at 2300 — 2200 cm in the ir spectmm. The position of the absorbance is influenced by conjugation and neighboring polar groups. This method has been successfully used in both kinetic and post-mortem characterizations of many polyurethane polymers. 

Water-Vapor Permeability. Water-vapor permeabiUty depends on the polymer used for the coating layer and its stmcture. Vinyl-coated fabrics have Httie water-vapor permeabiUty due to the coating layer. Although polyurethane polymer is water-vapor permeable, urethane-coated fabrics also have low permeabiUty values due to their soHd layer stmcture. On the other hand, man-made leathers have good permeabiUty values as high as that of leather due to their porous layer stmcture. The permeabiUty of grain-type is lower than that of suede-type, influenced by finishing method. 

The Polyurethane Polymer of 3,3-Dinitro-1,5-Pentane Diisocyanate and 2,2-Dinitro-1,3-Pro-panadiol. 

The Polyurethane Polymer of 3,3,5,7,7-Penta-nitro-5-Aza-1,9-Nonane Di isocyanate and 5,5,5-Trinitro-1,2-Pentanediol. 

The Polyurethane Polymer of 2-Nitraza-1,4-Butane Diisocyanate and 2-Nitro-2-Methy 1-1,3-Propanediol. 

The Postnitrated Polyurethane Polymer of Ethylene Di isocyanate and Ethylene Dinitramine. 

The Postnitrated Polyurethane Polymer of 3,3-Din itro-1, 5-Pentane with N, N-Bis (2-Hydroxy-ethyl) Oxamide. 

The Postnitrated Polyurethane Polymer of 3-Nitro-3-Aza-1,5-Pentane Diisocyanate and 5,5-Dinitro-1,2-Hexanediol. ... 

The Postnitrated Polyurethane Polymer of 3-Nitraza-1,5- Pentane Di isocyanate and 5,5,5-Tr initro-1,2-Pen tanedioL... 

The Postnitrated Polyurethane Polymer of 3,6-Dinitr0-3,6-Diaza-1,8-Octane Di isocyanate with 5,5- Di nitro-1,2- Hexanedi ol. ... 

The Postnitrated Polyurethane Polymer of 3,6-Dinitraza-1,5-Octane Diisocyanate and 2-Methyl-2-Nitro 1,3-Propanedio. n... 

Petrovic, Z.S. et al. Effect of silica nanoparticles on morphology of segmented polyurethanes. Polymer, 45, 4285, 2004. 

Polyurethane polymers are characterised by the presence of urethane — NHCOO — linkages in their repeat units ... 

These high energy species are extremely reactive, with themselves and with nucleophiles, and can generate runaway exotherms. With water, rapid evolution of carbon dioxide results. Some instances are reported [1], A compound of this class was resposible for the worst chemical industry accident to date. Di-isocyanates are extensively employed, with polyols, to generate polyurethane polymers. The polymerisation temperature should be held below 180°C or decomposition may occur which, in the case of foams, may induce later autoignition. 

This section describes the synthesis of oxazolidine esters used as polymer hardeners that cannot be synthesized using chemical catalysis, the synthesis of polyurethane polymers with methods that avoid the use of isocyanates and the enzymatic synthesis of polyesters with low molecular weight dispersity. 

Marans and Preckel " synthesized both the mononitrate (95) and the dinitrate (92) esters of metriol by using a similar strategy to that used for pentaerythritol trinitrate. Thus, nitration of both the mono- (90) and the di- (93) acetate esters of metriol, followed by selective hydrolysis of the acetate groups, yields (92) and (95) respectively the latter could be useful as a monomer for the synthesis of energetic polyurethane polymers. 

Polymer resins and pancake syrups Liquid polyurethanes Polymer melts ... 

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