Phase and Curing Behavior of Polybutadiene/Diallyl Phthalate Blends Monitored by FT-IR Imaging Using Focal-Plane...

The phase morphology and interfacial regions of cured and uncured polybutadiene/diallyl phthalate (PBD/DAP) blends that exhibit upper critical solution temperature (UCST) behavior have been characterized using an FT-IR microscopic imaging technique with focal-plane array detection. The observations of domain size and structure were based on monitoring characteristic infrared C-H, C [Formula: see text] O, and C-O modes of the blend components. The basic phase morphology of the uncured blend was monitored immediately after sample preparation and after 24 h. The average domain sizes of the uncured blend increased with aging by coalescence of smaller particles. The chemical compositions of the separated domains were determined by measuring ratios of integrated intensities and analyzed using a calibration curve. Finally, the blends were cured above the UCST and an apparently homogeneous network was obtained.