Urethanes, poly foams, flexible

Figure 1. Compound growth rate of poly ether flexible urethane foam.

Antagonism between antimony oxide and phosphoms flame retardants has been reported in several polymer systems, and has been explained on the basis of phosphoms interfering with the formation or volatilization of antimony haUdes, perhaps by forming antimony phosphate (12,13). This phenomenon is also not universal, and depends on the relative amounts of antimony and phosphoms. Some useful commercial poly(vinyl chloride) (PVC) formulations have been described for antimony oxide and triaryl phosphates (42). Combinations of antimony oxide, halogen compounds, and phosphates have also been found useful in commercial flexible urethane foams (43). 

Hydrosilation reactions have been one of the earlier techniques utilized in the preparation of siloxane containing block copolymers 22,23). A major application of this method has been in the synthesis of polysiloxane-poly(alkylene oxide) block copolymers 23), which find extensive applications as emulsifiers and stabilizers, especially in the urethane foam formulations 23-43). These types of reactions are conducted between silane (Si H) terminated siloxane oligomers and olefinically terminated poly-(alkylene oxide) oligomers. Consequently the resulting system contains (Si—C) linkages between different segments. Earlier developments in the field have been reviewed 22, 23,43> Recently hydrosilation reactions have been used effectively by Ringsdorf 255) and Finkelmann 256) for the synthesis of various novel thermoplastic liquid crystalline copolymers where siloxanes have been utilized as flexible spacers. Introduction of flexible siloxanes also improved the processibility of these materials. 

Naugard PS-30 is a liquid amine antioxidant typically used with phenolic antioxidants, phosphites, and synergists in poly-ether polyols to inhibit physical/color scorch associated with the production of flexible urethane foam. 

The superior characteristics of polyester polyol based polyurethanes are explained by a better crystalline structure [1, 7] in the urethane segment, compared to the majority of poly ether polyols which are amorphous [except polytetrahydrofuran (PTHF)], due to the superior secondary forces between the polyester chains [8] and also due to a superior thermal and fire resistance, compared to polyether polyol based polyurethanes. Polyester-based polyurethanes (flexible foams, coatings), have a superior solvent resistance compared to the polyether-based polyurethanes [8]. 

Silicone emulsiflyer, for flexible poly(urethane) foam ... 

Silicone emulsiflyer, for flexible poly(urethane) foam, 509 Niax L-6900 Surfactant, 509 Nirez 2150/7042 Terpene phenol flow modifler, 166 Nomex ... 

Uses Soft segment in formation of elastomers such as thermoplastic urethanes, polyether esters, polyether amides, coatings, adhesives and sealants, casting resins, and urethane foams Features Produces elastomeric end-prods, with hydrolytic stability, resist. to microbial attack, low temp, flexibility and elasticity Properties APHA 40 max. wax-like solid sol. in most org. solvs. barely sol. in water m.w. 650 sp.gr. 0.977 (40 C) acid no. 0.05 hyd. no. 166.2-179.5 flash pt. 215 C 0.025% water Storage Hygroscopic protect from moisture and air dry nitrogen blanket should be applied to open containers before resealing Polythix M [Poly-Resyn]... 

Poly(urethane ureas) are obtained in many aromatic isocyanate applications. For example, water-blown flexible polyurethane foam incorporates urea... 

Plasticized poly(vinyl chloride) (PVC), poly(urethane)s, poly(eth-ylene) (PE), and poly(ester)s are particularly sensitive to microbial attack. Flexible PVC is by far the main plastic in which biostabilizers are incorporated, followed by poly(urethane) foams, and other resins. PVC itself is resistant to microbial attack, however, plasticizers, fillers, pigments, lubricants, and other additives used in PVC are... 

Basically, flexible polyurethane foams are formed from polyols and isocyanates. The polyols have hydroxyl functionalities of at least 2 if the foam is to be made by a prepolymer process and of 3 or more if the foam is to be made by a "oneshot" process. The prepolymer process proceeds in two distinct steps while in the one-shot process, all reactants are intensively mixed together at the begiiming of the foaming process. Early in the development of urethane foams, the polyols were polyester diols now, however, by far the largest volume of polyols for urethane foams are poly(propylene oxide) polyols or poly(propylene oxide) polyols containing up to 25... 

Control of the reaction sequence in making flexible, open-cell, polyurethane foam using the one-shot process is accomplished by choosing the polyol, the surfactant, and the combination of tertiary-amine and organometallic, usually tin, catalysts. As in the previously described procedures for making urethane elastomers and microcellular products, for foams, polyols— poly(propylene oxide) polyols often containing minor amounts of ethylene oxide—are used. These polyols are selected by functionality, molecular weight, and reactivity (see Table 3). 

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