INFRARED SPECTRA AND PHASE CHANGES OF SOLID ANILINIUM HALIDES

1962 ◽  
Vol 40 (4) ◽  
pp. 622-629 ◽  
Author(s):  
A. Cabana ◽  
C. Sandorfy

The infrared spectra of anilinium chloride, bromide, and iodide, measured at 22 °C and at −190 °C, are presented. The spectrum of the chloride is essentially the same at both temperatures but the spectra of both the bromide and the iodide exhibit changes indicating a crystalline phase transition, in accordance with recent X-ray determinations of the crystal structures of these compounds.

2014 ◽  
Vol 1070-1072 ◽  
pp. 589-593
Author(s):  
Fei Peng Wang ◽  
Zheng Yong Huang ◽  
Jian Li

Commercial poly (vinylidene fluoride) (PVDF) films are uniaxially stretched with varying rates at 110 °C in order to endow PVDF piezo-and pyroelectric by crystalline-phase transition from α to β during the stretching. The crystalline phases are determined by infrared spectroscopy. The β-phase content and its fraction in films increase as a result of stretching with high rates. In addition, higher stretching rates yield a slight increase of γ phase. The crystallite size is evaluated by means of X-ray diffraction. It is found that the β-phase crystallites become smaller with fast stretching, whereas the α-phase crystallites are cracked and disappear at high-speed stretching of 2.5 /min.


2010 ◽  
Vol 108 (2) ◽  
pp. 024506 ◽  
Author(s):  
Ki-Ho Song ◽  
Seung-Cheol Beak ◽  
Hyun-Yong Lee

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hao Chen ◽  
João M. Maia

Abstract Extensional mixing elements (EMEs) that impose extension-dominated flow via stationary single-plane or double-plane hyperbolic converging-diverging channels were previously designed for twin-screw and single-screw extruders (TSE and SSE, respectively). In a recently published work by the authors, reactive extrusion was performed on PS/PA6 polymer blends TSE using EMEs and a crystalline phase transition of the minor phase in these droplets was observed as the size of droplet decreases from micron to submicron. Herein, we expand upon this work to SSE and study: a) The ability of the EMEs to improve dispersive mixing in the same blends; b) Assess the possibility of achieving the same crystalline phase transition in SSEs. The final blends were characterized by DSC, rheologically and morphologically via SEM, and the results show that while EME-based SSE leads to much improved mixing, better than non-EME TSE, the reduction in size of the PA6 disperse phase is not enough to induce the phase transition observed in EME-based TSE.


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