State of dibutyl phthalate molecules in plasticized poly(vinyl chloride)

It was found that the rotational motion of plasticizer molecules in the polymer matrix is hindered, the degree of hindrance differing for different molecules. With use of the data on the dibutyl phthalate (DBP) autodiffusion it was possible to evaluate the lifetime of the PVC-plasticizer solvates. This lifetime is a function of the amount of small molecules and of temperature. The solvatation in these systems is of the dynamic type. The "free" plasticizer is absent in samples containing 30-52 wt.% DBP. The measurements were made by the pulse NMR method. © 1979