A complete declam and the adhesive on aluminum, as tested in Table 1, were evaluated using this first commercial lot. Table 2 contains the results. Data in Table 2 show much higher heat-release values for 689 adhesive on aluminum than expected. Occasionally, relatively low values would be obtained, but high values would still be found in complete declams. Suggestions for the high heat-release values included poor dispersion of the fire retardants, interactions with specific materials in the declam structures and solvent retention.
Solvent retention can cause poor heat-release values.
3 Findings by Herb Curry reveal that residual solvent usually flashes off within 0.2 to 0.5 minutes. Therefore, a peak value that is much higher than the two-minute total could indicate solvent flashing off the sample and burning. If the peak and two-minute total values are both higher than expected, that could indicate chemical formation of a volatile such as unblocking of a blocked isocyanate. The amount of residual solvent depends on many factors. The material coming out of the drying ovens has a specification of less than 3 percent.