Relationships between ringed spherulitic morphology and miscibility in blends of poly[epsilon-caprolactone) with poly[benzyl methacrylate) versus poly(phenyl methacrylate)

Ringed spherulites are an interesting phenomenon that is observed only in v ery few miscible systems. For the first time, the relationship between the state of chain intermixing and the ring-band pattern was demonstrated. Two previously demonstrated miscible blend systems, poly(epsilon -caprolactone) (PCL) with poly(benzyl methacrylate) (PBzMA) and PCL with poly(phenyl meth acrylate) (PPhMA), were studied in order to understand the mechanism of rin g-band formation in the spherulites and the relationships between the ring- band pattern and the state of miscibility. In both miscible PCL/ PBzMA and PCL/PPhMA systems, extinction rings were observed within the PCL spherulite s. In the PCL/ PBzMA blend, the extinction rings are not as distinct towing to distortion) as those in the PCL/PPhMA blend system. Analysis was perfor med and discussions were made to reveal relationships between miscibility, interaction strength, and the pattern of the ring bands in the PCL spheruli tes in polymeric mixtures.