Kinetics of Cold Crystallization of 4-Cyano-3-fluorophenyl 4-Butylbenzoate (4CFPB) Glass Forming Liquid Crystal. I. Nonisothermal Process As Studied by Microscopic, Calorimetric, and Dielectric Methods

• DOI: 10.1021/acs.cgd.5b00328
• Publication Date: 2015-04-24T18:52:22Z
• Authors: Tomasz Rozwadowski; Maria Massalska-A...; Łukasz Kolek; Katarzyna Grzybowska; Andrzej Bąk; Krystyna Chłędowska
• Keywords: Crystal (programming language); Metastability; Atmospheric temperature range

For 4-cyano-3-fluorophenyl 4-butylbenzoate (4CFPB), the process of crystallization CrII phase was studied in microscopic (POM), calorimetric (DSC), and dielectric (BDS) nonisothermal experiments with various (0.5–50 K/min) heating metastable nematic obtained from its glass. Growth areas crystal texture during allows estimation degree crystallinity D(T) vs temperature curves similar to these basing on DSC heat flow for slow help relaxation method. Two types mechanisms seem be identified: (1) strong ϕ dependence full Tc(ϕ) half time t1/2(ϕ) up 5 K/min points diffusion-controlled mechanism energy barrier 57 kJ/mol, (2) small effect faster seems illustrate thermodynamic 180 kJ/mol. The scenario two is agreement results new method proposed by Mo et al., using combination Avrami Ozawa equations description crystallization. In addition 4CFPB, at higher range CrII–CrI transformation a stable CrI digitalized based DCS 1 K/min.