Non punking phenolic foam

A method for producing phenolic foam which comprises polymerizing a phenolic resole in the presence of an acidic polymerization catalyst, a blowing agent, and an aralkyl-polyalkylsiloxane in which the aralkyl and alkyl groups are bonded to silicon, the alkyl groups have from one to four carbon atoms and the aralkyl groups are of the formula, ##STR20## wherein R' is bivalent alkylene having two or three carbon atoms and R.degree. is hydrogen or methyl.

a method for producing phenolic foam which comprises polymerizing a phenol-formaldehyde resole in the presence of an acidic polymerization catalyst, a blowing agent and a foam-stabilizing component comprising a phenylethyl-modified polymethylsiloxane oil present in an amount from about 0.1 to about 10 parts by weight per 100 parts by weight of the resole, wherein said phenylethyl-modified polymethylsiloxane oil consists essentially of (i) monofunctional siloxy units the respective silicon atoms of which have two methyl groups bonded thereto, the third silicon-bonded organic group being methyl or phenylethyl, (ii) an average of from about one to about 200 moles of difunctional dimethylsiloxy units for every two moles of said monofunctional units, and (iii) from zero up to an average of about 100 moles, for every two moles of monofunctional units, of difunctional monomethylsiloxy units in which the second organic group bonded to silicon is phenylethyl, provided an average of at least about 0.5 and no more than about 100 moles of phenylethyl groups are present for every two moles of monofunctional units.

A method for producing phenolic foam which comprises polymerizing and foaming a reaction mixture containing a phenol-formaldehyde resole having a water content of no more than about 10 parts by weight per 100 parts by weight of resole, an acidic polymerization catalyst, a blowing agent, and a foam stabilizing component comprising an aralkyl-polymethylsiloxane oil having the average composition, ##STR21## wherein Me is methyl, a has a value of two or three, x has an average value from about 2 to about 80, y has an average value from about one to about 40, and the ratio of x:y has an average value from about 3:1 to about 1:1, said aralkyl-polymethylsiloxane being present in said reaction mixture in an amount from about 0.5 to about six parts by weight per 100 parts by weight of resole.