三聚氰胺基聚醚多元醇的合成及对硬质聚氨酯泡沫阻燃性能的影响

A novel melamine-based polyether polyol (HMMM-PG) was synthesized, which consisted of five different ether exchange products HMMM-PG5, HMMM-PG3, HMMM-PG4 and HMMM-PG2 in descending content order.The relative hydroxyl content of the productsis 447 mg KOH/g. A series of rigid polyurethane (PU) foams were prepared by the reaction of HMMM-PG with isocyanate, and the flame retardants dimethyl methylphosphonate (DMMP), aluminum hydroxide (ATH), ammonium polyphosphate (APP) and expandable graphite (EG) were added. The physical-mechanical properties, thermal properties and flame-retardant properties of PU foams were investigated by compressive strength test, thermal conductivity test, thermo gravimetric analysis, SEM, limiting oxygen index(LOI), cone calorimeter and X-ray photoelectron spectroscopy (XPS). The PU foamswith excellent physical-mechanical properties, thermal performance and flame retardant properties were found. With addition of 10 phr DMMP, 5 phr ATH, 15 phr APP and 20 EG, the compressive strength reaches 0.22 MPa, while thethermal stability and carbonation of foamsare improved.The SEM images show that ATH could form "villi" like substances while APP could form highly cross-linked polyphosphoric acid during combustion, which is covered on the surface of foams. The heat and flammable gas areblocked. In addition, the worm-like carbon layer formed by EG expansion can effectively shield heat.