In this work, the aggregation behavior of polyvinyl chloride/dioxane (PVC/D
OA) solution was discussed through light scattering and viscometric measure
ments. From the static light scattering results, PVC/DOA solution has a neg
ative value of the second virial coefficient, A(2) value(ca. -3.65 x 10(-4)
cm(3) mol g(-2)) at 30 degrees C, implying that a repulsive force appeared
between PVC chains and DOA. The dynamic light scattering results indicate
that the dynamic behavior of PVC solution could be classified into three re
gions by increasing the concentration of PVC. In the infinite dilution regi
on, [eta]C < 1, the single relaxation mode is considered related to the tra
nslational diffusion of the individual PVC coil. In the hydrodynamic screen
region, 1 < [eta]C < 4, the relaxation time distribution was divided into
two major relaxation modes; i.e. the fast mode resembled that of the indivi
dual PVC coil in the dilute solution, and the slow mode is considered relat
ed to the cluster formed from the aggregation of several individual coils.
At higher concentrations, [eta]C > 4, the polymer coils start to overlap an
d entangle further, then the third relaxation mode due to the transient gel
network originated from the aggregation of the clusters in the concentrate
d solution was observed. On the other hand, the relative amplitudes of midd
le and slow modes for semi-dilute solutions decrease with increasing temper
ature. At a temperature of about 50 degrees C, only a broad relaxation mode
was observed indicating that intermolecular aggregation is disintegrated w
ith increasing temperature, but the intramolecular aggregation of an isolat
ed chain still exists due to the poor affinity of DOA to PVC chains in this
temperature region. The poor solubility of the solvent used should be more
favorable to the intramolecular aggregation of PVC chains, resulting in co
mparatively complex dynamic behaviors in semi-dilute solutions. (C) 2000 El
sevier Science Ltd. All rights reserved.