In situ Raman scattering investigation of crystal phase transition in isotactic polybutene-1†

Abstract

iPB-1, known as golden plastic, exhibits remarkable physical and mechanical properties such as superior creep and stress resistance, high toughness stiffness, and tear strength, surpassing those of PE and PP. However, its widespread industrial application is limited by certain drawbacks, primarily related to its complex polymorphic behavior, which is not yet fully understood. In this study, iPB-1 was investigated in situ during heating, cooling, and crystal-phase transition by Raman spectra combining DSC and WAXS. The recorded results show that the scattering intensities around the shift bands at 847 and 883 cm⁻¹ (corresponding to form I and form II, respectively) in the Raman spectra can be used to trace the melting, crystallization, and transition of iPB-1. The form I and form II corresponding normalized Raman peak intensity show that the formation of the former occurs earlier than the decreasing of the latter on a logarithmic time scale. Guided by the well-known saying natura non facit saltus, a transition mechanism was proposed, which would be beneficial for the industrial applications of iPB-1.