Blowing Agent for OCF

One component polyurethane foam primarily use environmentally friendly, fluorine-free physical blowing agents. The most common agents currently in use are Dimethyl Ether (DME) and Alkanes (propane, butane, isobutene, LPG, propane-butane mixture).

Dimethyl Ether (DME)

Molecular Formula: CH₃OCH₃

Molecular Weight: 46.10 g/mol

CAS Registry Number: 115-10-6

It is a colorless, odorless gas at room temperature with a boiling point of -24°C and a melting point of -138.5°C, good water solubility, can reduce system viscosity. DME has low viscosity and surface tension, exhibits high solubility in both polar and non-polar organic substances, and is soluble in water. The ODP (Ozone Depletion Potential) is 0, has very low GWP (Global Warming Potential). The cost of DME is low, has good compatibility with polyols, can improve foam stability and performance in water blown systems. It is a good choice in market with mature technology, high foaming efficiency.

Propane-Butane Mixture(HAP)

The HAP has replaced the early blowing agent CFC-12, its ODP is zero, the cost of HAP is competitive, and can significantly reduce the production cost of OCF. When mixed with dimethyl ether (DME), it also can provide excellent foaming performance, resulting in a fine cell structure. However, the HAP/DME system also faces technical challenges, The choice of blowing agent dictates the foam's cell structure, strength, dimensional stability, insulating efficiency, and speed of cure.

For polyurethane foam, the blowing agent and the silicone surfactant/stabilizer/polyether are core partners that work closely together with complementary functions. The blowing agent is responsible for "generating foams," while the foam stabilizer is responsible for "stabilizing and controlling the structure of foams." They determine the final performance of the foam.