Influence of Vapor Pressure on the Crystallization Behaviors of BAPC
The kinetics of acetone absorption by BAPC has been widely investigated [9-19, 25, 26].
WAXD measurements were carried out to determine the crystal structure and cell parameters of BAPC films.
The maximum crystallinity of BAPC was obtained by isothermal crystallization at 185[degrees]C from the glassy state according to literature [24, 28], as shown in Figure 4d.
The crystal morphology of 10-[micro]m-thick BAPC samples was observed with POM after vapor-induced crystallization at 25[degrees]C under a pressure of 26.
Double melting endothermic peaks of acetone-exposed BAPC were observed by using DSC.
BAPC has a positive anisotropy meaning a higher polarizability along the chain backbone.
Several modified polycarbonates are compared with BAPC, which had been used in previous investigations, i.
BAPC has a positive anisotropy, meaning the highest polarizability along the orientation direction of the polymer chain.
In the copolymers with a balanced polarizability, the coefficient is about one third that of BAPC.
As pointed out in the Introduction, the residual birefringence in BAPC is dominated by 'frozen-in' contributions, but a major part of this frozen-in birefringence is not induced by flow but rather by shrinkage differences due to the anisothermal cooling and in addition to that by compression in the anisothermal state (7, 22).
1] the tensile stresses in the core are calculated as well below 1 MPa, in agreement with earlier results obtained on BAPC by layer removal (6).