Crystallization Behavior Of Poly-ε-caprolactone And Its Blends

The study of polymer crystallization behavior is an important direction of the research in polymer discipline. This paper is mainly with Polycaprolactone and Polycaprolactone/polyvinyl methyl ether blending system as the research object. The study is mainly about the crystallization kinetics of PCL and the crystallization behavior of the PCL/PVME blending system.First, adopt the DSC to study the crystallization kinetics of PCL, Isothermal and non-isothermal. Analyze the isothermal crystallization kinetics of poly-s-caprolactone (PCL) by the Avrami equation. The experimental results show that during the initial stage of the PCL crystallization, the Avrami index approximately equals3. It illustrates the heterogeneous nucleation of PCL as a three-dimensional spherulites growth. At the same time, with the crystallization temperature dropping, the value of T1/2, Tmax decreases, but its crystallization rate increases.Second, analyze the non-isothermal crystallization kinetics of PCL by the Ozawa equation and the Jeziorny equation. The analytical results show that, the initial stage of the PCL crystallization, when the Avrami index is about equal to4, the crystallization of PCL ishomogeneous nucleation growth. In the later PCL crystallization, In the later of PCL crystallization,when its crystallinity is98%, PCL crystallization existence of the secondary crystallization behavior,so the secondary crystallization behavior isthe undercooling affect.Finally, the study is PCL crystallization behavior in the polycaprolactone (PCL)/polyvinyl methyl ether (PVME) blending system. The main application equipment inclulds DSC, WAXD, POM. The results show that the crystallinity of the PCL polymer blends almost does not vary with the composition of the system changing; and that the presence of PVME in the blends does not change the crystal structure, but with the PVME content increasing, PCL melt absorb heat in the system is getting smaller and smaller. This means that as the PVME content in blends increases, the PCL content in blends gradually reduces, and in the process of melting, it can only appear obvious melting peak, but with the PVME content increasing, Spherulite growth rate decreases more significantly. This is because the existence of the PVME inhibits the PCL crystallization and the PVME works as a diluent.