3,7,14-Tri（s dimethylsilylsiloxy）-hept（a 3,3,3-trifluoropropyl）tricycloheptasiloxane（ TFP-H）, 3,7,14-tri（s dimethylvinylsilylsiloxy）-

hept（a 3,3,3-trifluoropropyl）tricycloheptasiloxane（ TFP-V）, and 3,7,14-tri（s dimethylallylsilylsiloxy）-

hept（a 3,3,3-trifluoropropyl）tricycloheptasiloxane（ TFP-A） were utilized as building blocks

for preparing three types of tris（trimethoxysilyl）-hepta（3,3,3-trifluoropropyl）-substituted open-cage silsesquioxanes

with different linker lengths（ TFP-Htri, TFP-Vtri, and TFP-Atri）. The methoxysilyl groups of

TFP-Htri, TFP-Vtri, and TFP-Atri were hydrolyzed and polycondensed to prepare silsesquioxane materials

denoted as TFP-IC-POSS@SSQs（ P-Htri, P-Vtri, and P-Atri）. The FT-IR spectra showed that newly

formed -Si-O-Si- bonds from the -Si（OMe）3 in TFP-IC-POSS@SSQs, suggesting that P-Vtri had the highest

contents of the random network structures, while P-Htri had the lowest contents due to the most steric effects

from the bulky TFP-IC-POSSs. P-Vtri showed the lowest thermal decomposition temperature with 5%

weight loss（ Td5） among the three TFP-IC-POSS@SSQs and P-Htri had a higher Td5 than P-Atri, suggesting

that the random network structures are more thermally labile than the cage-like structures. Mechanical

properties for the TFP-IC-POSS@SSQs on a nanometric scale were estimated by SPM measurements. The

elastic modulus for TFP-IC-POSSs@SSQs was in inverse proportion to the linker length as P-Htri > P-Vtri >

P-Atri. On the other hand, the adhesion force was in decreasing order as P-Vtri > P-Htri > P-Atri. The different

mechanical properties were the results by comprehensive effects from the organic moiety contents as

well as the contents ratio of the random network structure versus the cage-like structure due to the different

linker lengths.

Fatigue crack growth tests of aluminum alloy A2017-T3 adhesive joint with epoxy adhesion have been carried

out under mode I and mode II cyclic loadings. The effect of anodizing of adherent was investigated in

terms of strain energy release rate range ΔG. The crack growth mechanisms was changed from interface or

quasi-interface cracking to cohesive cracking by anodizing treatment. This effect resulted in an increase in

crack growth resistance, especially under mode I loading. The effect of moist environment on mode I fatigue

crack growth behavior was also investigated. When the specimens which was immersed in purified water under

constant temperature and period were tested with supplying water to the crack surface, the crack growth rate

significantly increased compared with that in laboratory environment. However, as the crack length increased,

the fatigue crack growth rate decreased rapidly because of crack closure effect of corrosion products on the

fracture surface.