Table 3.

Average WCA of PU coating prepared using different methods.

Samples	Method	Chemicals	Average WCA (°)
R-0	Spray coating	-	99.62 ± 3.38
N/7.0	Blending-spray coating	-	94.72 ± 6.00
S/7.0	Blending-spray-silane post-treatment	perfluorooctyltriethoxy silane	110.17 ± 4.85
E/20/2.0	Dual-layer spray coating	ethanol	18.04 ± 1.83
T/20/2.0		tetrahydrofuran	148.81 ± 2.96
P/20/2.0		paint thinner	152.71 ± 1.81