Rigid PUR foam

Fig. 2 a, b. Differential curves of the distribution of cell radii for rigid PUR foam based on polyester (grade PPU-307) of the apparent densities 40 kg m (a) and 500kg m (b). 

Fig. IS. Temperature dependence of the thermal conductivity, A., of a rigid PUR foam (r = 30.8 kg...

Shutov and Chaikin showed that for rigid PUR foams... 

Data calculated according to Eq. (49) (solid lines) and experimental data (points) for a rigid PUR foam at 65% relative humidity are shown in Fig. 22 (deviation 3%). 

Experimental data on rigid PUR foam coincide with 30% accuracy with values calculated from Eq. (50). It should also be noted that prolonged evacuation of PPU-305 samples containing sorbed water reduces tg 6 by a factor of 20—25. 

According to the data reported by Shutov and Chaikin the graph of rigid PUR foam (Grade PPU-3) electioconductivity G against the volume fraction of the polymer phase displays a maximum (Fig. 23), corresponding to the maximum of moisture abwrption. The analytical form of this dependence established by correlation analysis is... 

Only one of the electrical characteristics (tg 6) directly depends on the moisture absorption level According to other data ) obtained for a semi-rigid PUR foam (grade PPU-102,... 

Polke, D. (1996) The manufacture of PUR compound elements with economic and ecological aspects being taken into account, in Processing Workshop on Rigid PUR Foams, 26/27/28 March at Netherlands Congress Centre, The Netherlands, Crane Communications, London. 

Kaaria et al. measured occupational exposure to MDl during molding of rigid PUR foam. Airborne MDl was sampled on 2 MP impregnated glass fiber filters and determined by LC-UV-EC. Workers n = 57) from three different factories participated in the study. 

Fig. 3.150 Surface temperatures on a sandwich panel asbestos slate/rigid PUR foam/asbestos slate during the combustion of 5 dm of gasoline... 

Cl 15% P 1.44 5000- 20 000 mPa s Cast PMMA, rigid PUR foam, PF-resin, unsaturated polyester lacquers... 

Vircol 82 Albright and Wilson Phosphorus polyol — — — Rigid PUR foam... 

The first commercial smoke suppressant that was effective at a low proportion was the Ferrocene FE-55 of Arapahoe. However, its brown colour restricted its utility. It is still recommended for rigid PVC and rigid PUR foams, where a smoke reduction of 20 to 60 per cent is reached at a load of 0.25 to 0.75 phr (phr parts per hundred, i.e, parts to 100 parts of the principal component, the polymer). ... 

Rigid PUR foam, CA, vinyls, epoxy and polyester resins, latices... 

BMW dashboard ABS/PVC skin backed with semi-rigid PUR foam (courtesy ICI Polyurethanes). 

PVC is much too versatile to disappear from the scene altogether. PVC/ ABS foil, backed by semi-rigid PUR foam, is still the most widely used surface for instrument panels. More recently, PVC has been blended with PUR to provide more temperature resistant surfaces. The desire to eliminate volatiles altogether from surfaces exposed to temperature is producing new answers one of these is a flexible blend based on acrylonitrile, styrene and acrylic rubber. In 1993, Krauss-Maffei introduced a more radical development a process for producing a sintered thermoplastic surface on a foam backing in a single operation. 

Rigid PUR foam wastes were simultaneously aminolyzed with NH, ethylene diamine, diethylene triamine, hexamethylenediamine, or ethanolamine and alkoxylated by ethylene oxide, propylene oxide, butylene oxide, phenyl glycidyl ether, or styrene oxide optionally in the presence of a hydroxyl containing tert-amine (dimethyl ethanol... 

Wastes of cellular, flexible and elastomeric PUR were treated with diethanolamine at 140-190°C to give polyols having diethanolamino groups for use in the manufacture of rigid PUR foams [21]. 

Aging tests are performed in order to evaluate the suitability of semi-rigid PUR foams for use in automobile interiors, see Table 2.36. 

Another undesired reaction that can occur with sulfur-zinc stabilized PVC or PVC/ ABS films is a clearly perceptible smell of onions or garlic. Prerequisite for the occurrence of this phenomenon is direct contact between PVC film and PUR foam. The smell can occur in contact with both rigid PUR foams and PUR block foams. An intensive search for the cause of the smell concluded that the initiator is interaction between amine catalysts in the PUR systems with the sulfur-zinc stabilizer in the PVC or PVC/ABS film. The remedy for this is either to change the PUR foam or to use a sulfur-zinc-free stabilization in the PVC film [686]. 

Chemical bond cleavage in semi-rigid PUR foams can be caused by oxidative processes or by hydrolysis and re-cleavage of urethane and/or urea links and their resulting products [702]. 

Table 5.112 Chemical resistance of rigid PUR foam after 28 days of exposure at 20 °C[513]...

Polar solvents can severely damage foam material. However, foams exhibit only slight solubility in these media. Rigid PUR foam is resistant to most solvents found in glues, bituminous materials, wood preservatives, and sealing compounds. 

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