| 摘要 |
Polyisocyanurate foams are disclosed which are characterized by a combination of a high degree of fire resistance with low smoke evolution, low foam friability yet high compressive strength, and, most unexpectedly, the formation of a protective intumescent char over unburnt foam when the foam is subjected to combustion. This combination of advantageous features is achieved by employing in the foam forming reaction a minor amount of a polyol mixture prepared by the transesterification, with a glycol of molecular weight from about 60 to about 400, of a residue obtained from the manufacture of dimethyl terephthalate. |
