Size of the Alkyl Group R is the Principal Factor Determining the Wettability of Surface-Functionalized Polyethylenes (PE-CONHR and PE-CO2R) by Water.

摘要

Advancing contact angles Theta (a) were measured for a series of surface-functionalized polyethylene films bearing ester (-CO2C(n)H(2n+1))and amide (-CONH(n)H(2n+1)) groups having different sizes of alkyl group. The influence of the polar ester or amide functionality on Theta (a) is no longer detectable for alkyl groups having n >or= 6. The size of the alkyl group required to shield a polar functional group at the surface of the polymer from the contacting water inferred from these experiments is remarkable similar to that observed previously with the more highly ordered, self-assembled monolayers of omega-mercapto ethers (HS(CH2)16OC(n)H(2n+1)) on gold. (aw)