Thermal insulators, foams

Extruded Rigid Foa.m. In addition to low temperature thermal insulation, foamed PSs are used for insulation against ambient temperatures in the form of perimeter insulation and insulation under floors and in walls and roofs. The upside-down roof system has been patented (256), in which foamed plastic such as Styrofoam (Dow) plastic foam is appHed above the tar-paper vapor seal, thereby protecting the tar paper from extreme thermal stresses that cause cracking. The foam is covered with gravel or some other wear-resistant topping (see Roofing materials). 

Thermal Insulation. Foamed plastics (qv) are used as thermal insulation for aU types of constmction because of their low heat- and moisture-transmission values. Polystyrene is used either as foamed board or expandable beads. The foam may be faced with a stmctural surfacing material, eg, a kraft liner-board, to form a panel for insulating mobile homes. These foams can dupHcate the appearance of wood and be used as trim. Foams can also be used as backing, for example, on aluminum siding, to provide heat and sound insulation. Foamed beads can be incorporated in concrete to reduce its density and provide some thermal insulation. 

Sucrose reacts with diisocyanates leading to polyurethanes, which are used as thermal insulating foams, notably in cars. Partially protected sucrose esters can be used for the synthesis of better-defined polymers (Scheme 46).265 A first step of hydroxypropylation is sometimes necessary to obtain sufficient miscibility with the diisocyanate derivative, as well as for tuning the physicochemical properties of the polyurethane foams.78,305,420... 

Disposable cups and glasses for hot (only PS foam) and cold drinks, electrical fittings, CD case (jewel box), Airfix model kits, food containers, coat hangers, hair combs, TV cabinets, expanded foam packaging, foam thermal insulation, foam ceiling tiles, insulated food containers. 

Polystyrene is used as a thermal insulation (foam) and in wall paints. 

CAN/ULC S770, Standard Test Method for Determination of Long-Term Thermal Resistance of Closed-Cell Thermal Insulating Foams, 2009. 

Polystyrene Mass-produced transparent articles, thermoformed packaging, etc. Thermal insulation (foamed), etc... 

HCFCs were used in the first instance to replace CFCs in a transitional phase and, imtil the end of 2002, HCFC-141b was still the number one physical blowing agent in North America. The London Amendment to Montreal allows the temporary use of HCECs to continue in some countries imtil 2040. US companies are still allowed to use HCFCs for thermal insulation foams and to import blended foams containing HCFC-141b until 2010. European usage can also continue for the manufacture of exported foam products to certain countries until the end of 2009. 

Promotion of cellular structure, reducing density, cost of materials and shrinkage and improving the electrical and thermal insulation — foaming... 

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