Linear PCL (poly(ε-caprolactone)), SAN (styrene-acrylonitrile copolymer) and TAIC (triallyl isocyanurate) were melt blended, and the blends were then subjected to different doses of electron beam irradiation to prepare three series of crosslinked PCL and PCL/SAN blends with different gel contents. The crosslinked PCL/SAN blends were observed by a phase-contrast optical microscope (PCOM), which disclosed that phase separation did not occur, indicating that PCL and SAN components were miscible. Differential scanning calorimetry (DSC) was applied to study isothermal crystallization kinetics of crosslinked PCL and PCL/SAN blends. It was found that for the samples with close crosslinking degrees, the crystallization kinetics of the samples became significantly slower with increasing SAN content. When the SAN contents in the blends were the same, the crystallization rate became slower as the degree of crosslinking increased. For the blends with close degrees of crosslinking, the linear portion and the crosslinked portion were separated from the crosslinked blends, and the study on their respective crystallization kinetics by using DSC and polarized light microscope (POM) revealed that it was the incorporated SAN component rather than the crosslinked network that mainly contributed to the slowdown of crystallization rate of PCL in the crosslinked blends. Furthermore, the non-isothermal crystallization behaviors of the crosslinked blends during the cooling process verified the above conclusion. 

Keywords: Poly(ε-caprolactone), Styrene-acrylonitrile copolymer, Electron beam irradiation, Crosslinked, Crystallization kinetics, Non-isothermal crystallization 

doi: 10.11777/j.issn1000-3304.2020.20168