ABSTRACT

HOCHr-(-NH-CO-NH-CH:z-],.-NH-CO-NH-CH20H After cross-linking with an excess of formaldehyde or with a source of this aldehyde such as hexamethylenetetramine the following network

is obtained:

The cross-linked polymer is infusible and insoluble. The basic chemistry of the UF polymer is the same as that for other applications, except that foams must cure at room temperature within the first few minutes, as compared to adhesives or mouldings which cure at high temperatures (lSO"C + ).