Blowing agents Alternative

Lorenzetti, A. Synthesis of modified cellular polymers Study on alternative blowing agents in relation to thermal insulating properties and fire behaviour. PhD Disertation, Padova University, Padova, Italy, 2002. 

Rigid Polystyrene Foams and Alternative Blowing Agents... 

RIGID POLYSTYRENE FOAMS AND ALTERNATIVE BLOWING AGENTS 205... 

A search for alternate blowing agents for urethane foams became necessary in 1987 following the Montreal Protocol, which mandated the development of foams with substantially reduced CFC content by 1995. 

HCFCs. Alternative blowing agents for CFCs, for the time being, are HCFCs (hydrochlorofluorocarbons) as shown in Table 7A, in which HCFC-141b is the most feasible alternative blowing agent for CFC-11. However, HCFCs also have problems, i.e., higher costs, and a small ozone-depletion potential, and therefore, HCFCs are also expected to be phased out by 2020. 

Perf1uorinated hydrocarbons. Table 7D Alternative Blowing Agents (HFEs) ... 

The need for alternative blowing agents to replace CFCs was discussed in the section on blowing agents. It was noted that the production and use of CFCs having an ozone-depletion effect will be banned worldwide by 1995. 

Alternative blowing agents for CFCs are HCFCs, e.g., HCFC-141b, HCFC-123 and HCFC-22. The combined use of HCFCs and water as blowing agent was also proposed (153g). The sole use of HCFC-22 as... 

Volatilization of a low-boiling liquid, either by the heat liberated by an exothermic reaction, or by externally applied heat. Commonly used liquids are chlorofluoro-carbons (CFCs). This is the most widely used technique in the production of rigid polyurethane foams. However, due to the ozone depletion problem in the stratosphere, they must be phased out and industry is presently searching for alternative blowing agents. 

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