| 摘要 |
An aqueous phenol formaldehyde resole, suitable for use in the manufacture of phenolic foam insulation, has a molar ratio of formaldehyde to phenol in the range of from about 1.7:1 to about 2.3:1, and a weight average molecular weight greater than 800. Preferably, the resole also has a number average molecular weight greater than 350 and a dispersivity greater than about 1.7. Phenol formaldehyde resoles having these characteristics are processable into phenolic foams having these characteristics which make them especially useful as an insulation material. There is also disclosed foamable phenolic resole compositions prepared from the phenolic resoles, and phenolic foams prepared from the compositions. |
