Outdoor Weathering Picatinny Arsenal Studies

Weathering studies after exposures up to one year were also made by Picatinny Arsenal on the adhesives covered in Table 10.8, along with several additional adhesives. The results are given in Table 10.9 as percent retention of original joint strength. In addition to controls, the following climates were used  

Adhesive Type Test Temperatures ( O Average Shear Strength (MIL-STD-304 ) (MPa)  

The joints with the two-part epoxy-anhydride adhesive ( 5), the two-part aliphatic amine-cured polysulfide-modified epoxy ( 6), and the two-part mixed amine-cured, filled epoxy ( 7) fell apart at the Panama site. Numbers 5 and 6 both fell apart during the second year of the program. The 6 joints fell apart during the third year, and also showed a sharp decrease in strength after three years at the Picatinny site. Joints 8, 9, 10, and 11 retained better than 50% of their original joint strength after three years at all test temperatures and sites. 

Column Heading Polymer Type Ti-ade Name Manufacturer Cure Temperature (°C) 

4 Polyamide-epoxy Epon-828A -140 Shell Corp. 121 

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