Alcoholization, because of the power supply function of alkyl, makes O take more negative charge, which is naturally not conducive to the attraction of electron clouds between O and H, and its polarity is small.

For p-phenol, because of the P-π * * yoke of O and benzene ring, O's electrons are biased towards benzene ring, which makes O lack of electrons more than before, which is beneficial to attract the electron cloud between O and H and is more polar.