The molecule of PVPK30 is a butyrolactam structure. It contains a more polar lactam group with a dipole moment of 40, which makes it hydrophilic and polar-philic. In addition, it has non-polar methylene (-CH2-) and methine (-CH=) groups on the molecular ring and in the long chain to make it lipophilic. The environment at both ends of the dipole amide group in the molecule is also different. From the point of view of the molecular model, the oxygen atom is bare, and the section containing the N atom is just surrounded by methyl and methylene groups. The molecular structure of PVPK30 makes it surface active and can be used as a polymer surfactant.