Polymers foaming

Foamed polymers Foamed sheet Foamed silicone rubber Foam fractionation... 

Strengths and moduli of most polymers increase as the temperature decreases (155). This behavior of the polymer phase carried over into the properties of polymer foams and similar dependence of the compressive modulus of polyurethane foams on temperature has been shown (151). 

E. Shutov, Integral S tructural Polymer Foams, Spriager-Vedag, Berlin, 1986. 

Other minor uses of ethyl chloride iaclude blowiag agents for thermoplastic foam (51) and styrene polymer foam (52), the manufacture of polymeric ketones used as lube oil detergents (53), the manufacture of acetaldehyde (qv) (54), as an aerosol propellent (55), as a refrigerant (R-160), ia the preparation of acid dyes (56), and as a local or general anesthetic (57,58). 

The cells in foams are polyhedral, like grains in a metal (Fig. 25.8). The cell walls, where the solid is concentrated, can be open (like a sponge) or closed (like a flotation foam), and they can be equiaxed (like the polymer foam in the figure) or elongated... 

Fig. 26.4. Young s modulus for wood depends mainly on the relative density p/p,. That along the groin varies os p/p, that across the groin varies roughly os like polymer foams.

Thermal insulation is available over a wide range of temperatures, from near absolute zero (-273 C) ( 59.4°F) to perhaps 3,(1()0°C (5,432°F). Applications include residential and commercial buildings, high- or low-temperature industrial processes, ground and air vehicles, and shipping containers. The materials and systems in use can be broadly characterized as air-filled fibrous or porous, cellular solids, closed-cell polymer foams containing a gas other than air, evacuated powder-filled panels, or reflective foil systems. 

The smoking salons of the Hindenburg and other hydrogen-filled dirigibles of Ihe 1930s were insulated with urea-formaldehyde polymer foams. The structure of this polymer is highly cross-linked, like that of Bakelite (Section 31.5). Propose a structure. 

Trzaskoma, P. P., et al., Characteristics of Rigid Polymer Foams as Related to their Use for Corrosion Protection in Enclosed Metal Spaces, NACE, 1999. 

Polyurethane Foams, 2nd ed., Dow Plastics, Midland, MI, 1997 (c) N. C. Hilyard and A. Cunningham, Low Density Cellular Plastics, Chapman and Hall, New York, 1994 (d) D. Klempner and K. C. Frisch, Handbook of Polymer Foams and Foam Technology, Hanser, Munich, 1991. 

Application of Statistical Experimental Design to Development of Low-Density Polymer Foams... 

We are applying the principles of statistical experimental design to the development of low-density polymer foams for use as direct-drive high-gain targets for Laser Inertial Confinement Fusion (ICF). Both polystyrene (PS) and resorcinol-formaldehyde (RF) foams are being developed. 

The samples most commonly tested in compression are foams and rubbers, which experience compressive forces during use. Very often, the polymer foams that experience compression are not readily visible to us, even though they are all around. Polymer foams are widely used in carpet underlay, upholstery, shoe insoles, backpack straps, bicycle helmets, and athletic pads. Solid rubbers are much more visible, including automobile and bicycle tires, gaskets and seals, soft keys on calculators, and shoe soles. 

Research and development technologists at the Dow Chemical Company can characterize materials in a variety of ways. One material property that is especially critical in polymer foaming and processing technology is density. A tool used for measuring the density of a material is called a pycnometer. There are many different manual and automatic types to choose from. For extremely accurate and precise density measurements, an easy-to-use, fully automatic gas displacement pycnometer is utilized. Analyses are commenced with a single keystroke. Once an analysis is initiated, data are collected, calculations performed, and results displayed without further operator intervention. 

Structural foams. Rigid foams made from thermosets. See polymer foams. 

Hedrick JL, Di Pietro R, Plummer CJG, Hilborn J, Jerome R (1996) Polymer 37 5236 Charlier Y, Hedrick JL, Russel TP, Di Pietro R, Jerome R (1995) Polymer 36 4529 Hedrick JL, Charlier Y, Russel TP, Swanson S,SanchezM (1995) Polymer 36 1315 Hedrick JL, Di Pietro R, Charlier Y, Jerome R (1995) High performance polymers 7 133 Hedrick JL, Di Pietro R, Hawker C, Jerome R (1995) Polymer 36 4855 Hedrick JL, Labadie JW, Russel TP, Hofer D, Wakharkar V (1993) High temperature polymer foams. Polymer 34 4717... 

Shutov FA (1991) Blowing agents for polymer foams. In Klempner DC, Frisch KC (eds) Handbook of polymeric foams and technology. Hanser, Munchen, chap 17... 

Shawbury, Rapra Technology Ltd., 2001, pp.l46. 30 cms., 1/6/01. Rapra Industry Analysis Series POLYMER FOAMS. TRENDS EM USE AND TECHNOLOGY... 

Patent Number US 5844009 A 19981201 CROSSLINKED LOW-DENSITY POLYMER FOAM... 

Patent Number US 5817705 A 19981006 SHORT TIME FRAME PROCESS FOR PRODUCING EXTRUDED CLOSED CELL LOW DENSITY PROPYLENE POLYMER FOAMS... 

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