Corrosion testing of urea-formaldehyde foam insulating material

• Main Authors: Weil, R., Graviano, A., Sheppard, K.
• Format: Report
• Language: English
• Published: Stevens Inst. of Tech., Hoboken, NJ (USA). Dept. of Materials and Metallurgical Engineering 1980
• Subjects: Buildings; Urea; Aldehydes; Corrosive Effects; 36 Materials Science; Organic Compounds; Elements; Thermal Insulation; Dispersions; Amides; Chemical Reactions; Formaldehyde; Foams; Compatibility; Corrosion; 32 Energy Conservation; Consumption; And Utilization; Materials Testing; 360405 > Materials > Polymers & Plastics > Degradation & Erosion > (-1987); Metals; Carbonic Acid Derivatives; Organic Nitrogen Compounds; Colloids; Testing 320100* > Energy Conservation; & Utilization > Buildings; Carbonic acid
• Online Access: https://doi.org/10.2172/5056518; https://digital.library.unt.edu/ark:/67531/metadc1054404/

Two tests of the corrosiveness of urea-formaldehyde (UF) foam insulating materials were compared. One test, the Timm test, had test coupons foamed in place. In the second, the Canadian test, blocks of foam already set were placed in contact with test coupons. The Timm test uses 10 gage thick coupons, while the Canadian test specifies 3 mil thick ones. Two samples of UF foam were tested by the Timm and the Canadian tests. The electrical-resistance probes showed that the corrosion rate against steel was initially quite high, of the order of 12 to 20 mpy (mils per year). After about 20 days, the rate was almost zero. In the Timm test, the corrosion rates of steel coupons were of the order to 0.5 to 2 mpy when averaged over the 28 or 56 day test period. The greater corrosion rate of the thick coupons in the Canadian test as well as poor reproducibility of the corrosion rates was attributed primarily to variations in the contact areas between the sample and the UF foam. The corrosion rates of galvanized steel coupons in the Canadian test in several cases exceeded the failure value. In the Timm test, the corrosion rates averaged over the whole test period were quite low. The corrosion rates of copper and aluminum in both tests were quite low. On the basis of the results of this study the following recommendations for a corrosion-test procedure for UF foam were made: two corrosion tests should be conducted, one for foam while curing and one after it has stabilized; the Timm test for corrosiveness while curing should be used, but for only 1 to 2 days; the test for corrosiveness after stabilizing should be of the accelerated type such as the Canadian one. To insure a constant-contact area, thicker coupons should be used; and the coupons for both tests should have a controlled part of the area not in contact with the foam to simulate field conditions.