Polyisocyanurate foam thermal insulation

The bulk of the ngid polyurethane and polyisocyanurate foam is used in insulation. See also Insulation (Thermal) More than half (60%) of the rigid foam consumed in 1994 was in the form of board or laminate die remainder was used in pour-in-place and spray foam applications. 

A variety of cellular plastics exists for use as thermal insulation as basic materials and products, or as thermal insulation systems in combination with other materials (see Foamed PLASTICS). Polystyrenes, polyisocyanurates (which include polyurethanes), and phenolics are most commonly available for general use, however, there is increasing use of other types including p olye thylene s, polyimides, melamines, and poly (vinyl chlorides) for specific applications. 

BS 5608 1986 Specification for Performed Rigid Polyurethane (PUR) and Polyisocyanurate (PIR) Foam for Thermal Insulation of Pipework and Equipment, 9 pp... 

Though closed-cell rigid polyurethane foams are excellent thermal insulators, they suffer form the drawback of unsatisfactory fire resistance even in the presence of phosphorus- and halogen-based fire retardants. In this context, polyisocyanurates, which are also based on isocyanates, have shown considerable promise. Isocyanurate has greater flame resistance then urethane. Although rigid polyurethane is specified for the temperatures up to 200°F (93°C), rigid polyisocyanurate foams, often called trimer foams, withstand use temperatures to 300°F (149°C). Physical properties and insulation efficiency are similar for both types. 

Kusan-Bindels and Friedrichs [57] have discussed the measurement of this property in rigid polyisocyanurate foams. An increase in the thermal insulation index of this polymer improves temperature stability and mechanical properties, even at 250 °C. 

In situ foaming is an another typical on-site application used mainly for insulation purposes. Since rigid PU and polyisocyanurate foams provide the most energy efficient and versatile thermal insulations, they are preferable for use in roof and wall system applications, for both residential and commercial buildings. 

Residential Construction. Owing to rising energy costs, the cost and low thermal conductivity are of prime importance in wall and ceiling insulation of residential buildings. The combination of insulation efficiency, desirable structural properties, ease of application, ability to reduce air infiltration, and moisture resistance has led to the use of extruded poljmieric and polyisocyanurate foam in residential construction as sheathing, as perimeter and floor insulation under concrete, and as a combined plaster base and insulation for walls. 

The first book on the reactions of carbon cumulenes, treating the cycloaddition reactions of ketenes in depth, was written by Staudinger in 1912 Staudinger already realized that cycloaddition reactions of ketenes are common, and often ketenes were only isolated as cyclodimers. The cyclodimers of isocyanates became prominent in the development of polyurethanes in the IG Farben Laboratory in Leverkusen, Germany in the early 1930s and the cyclotrimerization of diisocyanates led to the development of polyisocyanurate foams, with thermal stability superior to rigid polyurethane foams in the 1960s. Today, polyisocyanurate foams are used in the insulation of the fuel tank of the space shuttle. Also, carbodiimide derived cellular plastics with improved thermal stability are of interest. In recent years, cumulene derived polymers became of interest as one-dimensional molecular wires. 

HH-I-1972/2(1) Insulation Board, Thermal, Polyurethane or Polyisocyanurate, Faced with AsphaltlOrganic Felt, AsphaltlAsbestos Felt or As-phaltIGlass Felt on Both Sides of the Foam, 3 October 1985, 2 pp amend + 3 pp base spec (FSC 5640) (YD)... 

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