Synchrotron and Raman Study of the Rotator Phases and Polymorphism in Tricosane Paraffin

Polymers

JuanC. Martínez¹  MaríaL. Cerrada²  Ernesto Pérez²  Enrique Blázquez-Blázquez²  Rosa Barranco-García² 

[1] ALBA Synchrotron Light Source, Carrer de la Llum 2-26, Cerdanyola del Vallès, 08290 Barcelona, Spain;Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain;

关键词: tricosane paraffin;    synchrotron SAXS and WAXS;    polymorphism;    rotator phases;    variable-temperature Raman spectroscopy;    transient structures;   

DOI  :  10.3390/polym12061341

来源: DOAJ

【 摘 要 】

A detailed study of the phase behavior of n-paraffin C₂₃H₄₈ has been performed by means of real-time variable-temperature experiments with synchrotron radiation. Two detectors were employed for simultaneous analysis of the small-angle (SAXS) and wide-angle X-ray-scattering (WAXS) regions. This paraffin presents a very interesting phase behavior, involving two crystal polymorphs, three rotator phases and the liquid state. The Ostwald rule of stages is invoked to find similarities of the rotator phases with the eventual transient mesomorphic structure in the multistage model of polymer crystallization. That study is complemented by variable-temperature Raman experiments covering frequencies down to 150 cm⁻¹. It was found that the low-frequency region is the most informative regarding the phase transitions, and specifically the intensity of the first overtone. From these analyses, several parameters are evaluated as function of temperature.

【 授权许可】

Unknown