minutes, periodically breaking the vacuum to rupture the bubbles formed. The uncured

elastomer remains workable for approximately 1 hour.

 For modified samples, oils were added to the resin before the addition of curing

agent at the appropriate concentrations and mixed together. Curing agent was then added

and the procedure was followed as above. For non-functionalized oils, the resin to curing

agent ratio remained 10:1. For vinyl-terminated oils, the curing agent percentage was

increased to account for the increase in vinyl groups. Unmodified samples were cured at

room temperature, while vinyl-terminated samples were cured at 800C for the appropriate

amount of time, as seen in Table 3.3.




Table 3.3 Curing conditions for silicone elastomer samples
Sample Curing Agent Needed Cure Time and
 Temperature
5% 2-3 cSt vinyl term (5% LMW) 0.16 x mass resin 4.5 hr at 80C
5% 1000 cSt vinyl (5% HMW) 0.1011 x mass resin 2 hr at 80C
15% vinyl tris 0.26 x mass resin 12 hr at 80C
Unmodified and nonfunctional oils 0.10 x mass resin 24 hr at RT


Modulus Determination

 Modulus values were obtained by Leslie Wilson and Amy Gibson and the values

are used for material selection purposes only. A brief explanation of the method used is

included here. Tensile specimens were made using an ASTM D1822-68 type L dogbone

die, resulting in a 1-inch gauge length. Each sample was individually measured and the

thickness of the samples was -1 mm. Tensile measurements were made according to

ASTM D412-97 on an Instron model 1122 equipped with the TestWorks 3.07 software

for analysis. The dogbones were tested via crosshead displacement at a rate of 2