Soft foams

Polyurethane, thermoset TSUs have du-rometers range from soft cushion to glass hard with superior wear resistance. Use includes skateboard wheels, solid tires, floor coatings, marine finishes, etc. A major use for soft-foam is automotive bumpers another is upholstery. Property improvements are made with different added fibers and fillers in... 

COATINGS PREPARED FROM POLYURETHANE SOFT FOAM RECYCLING POLYOLS... 

One of the great benefits of polyurethane is versatility. With only slight changes in chemistry, one can make products ranging from soft furniture cushions to automobile bumpers and infinite numbers of other products. Depending on the application, a polyurethane chemist can vary density and stiffness to achieve acceptable product performance. The chemistry is in fact much more versatile than is required. Figure 2.19 covers soft foams, rigid foams, and other polyurethanes. We will provide more details later in this chapter, particularly as to how the independent properties of density and stiffness relate to end uses. 

Heat-resistant [218] soft foams were prepared from the blends of hdPE with E-P random copolymers. The azodicarbanamide acts as a thermal antioxidant and the crosslinking of the blend was increased by electron beam radiations and foamed at 225 °C with 2320% expansion. A blend of 35 wt.% PE-PP (8 92), 15 wt.% E-P block copolymers, and 50 wt.% EPDM showed accelerated weathering resitance [219] 1000 h probably due to crosslinking between constituents of the block copolymer, polyblend and EPDM. The effect of filler and thermodynamic compatibility on kaolin-filled PE-PP blend was studied by Lipatov and coworkers [220]. The thermodynamic interaction parameter (%) decreased and thermodynamic stability increased by filler addition, the degree of crystallinity decreased with increasing thermodynamic compatibility of the components due to sharp decrease in the phase separation rate during cooling. 

Classification. Flexibie urethane foams have the largest market of all polyurethane products. The production properties and applications of various flexible urethane foams are described in the following sections. Flexible urethane foams are defined as open-cell urethane foams having the property of complete recovery immediately after compression. They can be classified into two kinds, i.e., polyether foams and polyester foams. Polyether foams are further classified as follows conventional flexible foams, high-resilience flexible foams (HR foams), cold-molded foams, super-soft foams, and viscoelastic foams. 

Polyethersiloxancs have surfactant properties. They ate utilized in large quantities as foam stabilizers in the manufacture of polyurethane hard and soft foams, the polyether component for this application being a copolymer of ethene oxide and propene oxide. Polyethersiloxancs are, however, also used in antifoaming formulations, as a gloss and deaeration additive in paints and as textile auxiliaries. 

Divers. [European Master Batch] Dispersions of fMgments in plasticizers dispersion of foaming agent in PVC soft foam. 

There is a wide range of polymers from soft foams to rigid composites for which. separate industries have developed. Each has its own individual test methods and. for the major types of polymers, texts exist that detail these procedures. There are, however, many similarities between different polymer types and frequently it is necessary for laboratories to consider a spectrum of materials. Consequently, there are advantages in a book that comprehensively covers the whole polymer family, describing the individual methods as well as discussing the approaches taken in different branches of the industry. 

Extra-soft foam. [Data from Brunner, E. Huber, A., US Patent 4,070,107, Mar. 14,1978.]... 

Artificial leather. Soft foam. [Data from Eichhloz, H, Martinz D O, Solvin Paste PVC Handbook. Solvay, 2010.]... 

There are many different types of hearing protection on the market. The simplest type is an earplug which is placed within the ear. Typically, these are soft foam which conform to the ear... 

TCEP production in Germany has been diseontinued in 1997. TCEP is no longer used in soft foams for mattresses and upholstery. 

A - Soft foam B - Hard foam C - Soft and lower-density foam, blown with natural... 

Integral skin PUR foams are made by injecting the reactants into a closed (vented) or open mold. Reaction under fliese conditions produces a foam with a high-density outside skin layer and a soft foam interior. Common products such as steering wheels, footwear components, and computer housings generally employ integral skin PUR foams. 

The stractural formulas of the common polyisocyanates used in the preparation of polyurethanes are shown above. The polyethers prereacted with excess isocyanate to yield an isocyanate end-capped prepolymer are stable viscous liquids under dry conditions. These mixed with water and catalysts produce a soft foam used in upholstery and other applications. The more popular and economic route to producing foam is the one shot process where the reactants, catalysts, and additives are all mixed together in a mixing head and spread onto a moving trough to obtain slabstock of the foam. Typically the mixing head is designed... 

Because plate-and-frame and tabular configurations are used widi the most contaminated fluids, mechanical cleaning techniques are used. In the case of plate-and-frame systems, die equipment may be disassembled and scrubbed, while in the tube configurations oversized soft foam plugs are driven through the tubes by pressure. 

Polyurethanes (PUs) are a family of condensation polymers that include the urethane (-NHCOO-) group in the chemical structure (Figure 5.1). The history of PUs started in 1937 when Dr Otto Bayer of Bayer Germany invented the diisocyanate polyaddition process. The early applications of PUs were mainly on soft foams and nonsegmented semicrystalline fibers. The lack of rubber materials during WWII has led to the intensive development of PU elastomers. In 1950, Bayer launched the first PU elastomer product, Vulkollan rubbers. Since then, PU elastomers have been used extensively, particular in medical, textile, automobile, and architecture industries [1-3]. 

---