Final Report - Strategic Environmental Research and Development ...

good grip on the dolly, the equipment was zeroed and the hydraulic pump was activated by
pumping the level. The pull rate must be kept at approximately 100 psi/s. Then, the measurement
was recorded and pictures were taken from the failure surfaces for analysis.
The tape test was performed following the ASTM D3359-09 Standard Test Method for
Measuring Adhesion by Tape Test. Samples were exposed to DI water at 60°C for four days
before performing the test. After exposure, the samples were dried with a Kimwipe and the
ASTM D3359 guidelines were followed to perform the test. Six incisions ¾ inch long were
created in a parallel manner having 2 mm of separation between each incision. Then six more
incisions were created with the same characteristics, but perpendicular and centered to the first
ones. Then the debris was cleaned with a dry Kimwipe and 3M 250 tape was placed on top of the
incisions. A roller with a weight of 4 ½ pound was rolled above the tape ten times to press the
tape against the sample. Finally, the tape was manually removed at 180° direction in one motion.
The surface was photographed for each sample and the delaminated area was calculated using
the Clemex Vision software. The samples were classified following the standard classification in
terms of delaminated area percent.
5.4.3.6 Other measurements
The Young’s modulus is a parameter needed to calculate the adhesion strength of primers to the
substrate. This parameter was determined from tensile tests performed on at least four samples of
the specific primer. The samples were prepared by mixing the components of the coating in the
appropriate ratio followed by pouring it in a Teflon mold that has a groove of 50 x 25 x 0.25 mm.
After it was cured, the sample was removed carefully using a blade and tweezers. Then an
aluminum template 2 mm thick with a 20 mm gauge length was used to give a dog bone shape to
the primers. The samples were placed between the two templates and it is kept in place using two
3 mm dermal punches (Acuderm Inc.). The punches are introduced carefully to avoid primer
stretching. Surgical blades (Bard-Parker No. 15) were used to cut shape using a single cut to
avoid defects that could create stress concentration. Before performing the tensile test, the
thickness of the primer was measured. The primer was placed between two glass slides of known
thickness and the thickness was measured using a digital micrometer. The tensile test was
performed using a load cell (TestResources, Model 1000R12) and a force transducer with a
capacity of 50 lbf (TestResources, model SM-50-294) at a strain rate of 0.1667 inch/s, as
recommended by the ASTM D882-10 standard test method for tensile properties of thin plastic
sheeting.
A Veeco Contour GT-K optical profilometer and the metrology application Visio64 TM v5.30
(Bruker) were used to assess the average roughness and real surface area (including roughness)
of the different substrates after abrasion. Four measurements were taken using a 5X objective
and a 1.0 multiplier, resulting in a field of view with dimensions 0.96 x 1.28 mm 2 . The images
were adjusted by using the terms removal option in the software, specifically the tilt only mode
to produce a plane fit and avoid any calculation error due to an inherent tilt.
Thickness measurements were performed using the Elcometer ® 456 Basic ferrous and nonferrous
coating thickness gage.
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