PVA is an atactic material that exhibits crystallinity. In terms of microstructure, it is composed mainly of 1,3-diol linkages [-CH2-CH(OH)-CH2-CH(OH)-] but a few percent of 1,2-diols [-CH2-CH(OH)-CH(OH)-CH2-] occur, depending on the conditions for the polymerization of the vinyl ester precursor.

The specific gravity of PVA is ranging from 1.26 to 1.31, which is heavier than that of water. Low agitation speedor unfavorable agitating condition sometimes causes coarse particles to precipitate and to block the outlet ofthe dissolving tank. Hence, a flush valve or tank valve is recommended to be installed in the bottom of the vessel to prevent the particles from blocking the discharge line.