X-Ray Determination of Crystallinity in Deformed Rubber

1955 ◽  
Vol 28 (4) ◽  
pp. 999-1006 ◽  
Author(s):  
S. C. Nyburg
Keyword(s):  
Heat Treatment ◽  
Pure Shear ◽  
Degree Of Crystallinity ◽  
Simple Extension ◽  
Amorphous Halo ◽  
Volume Changes ◽  
X Ray ◽  
Constant Deformation ◽  
The Degree Of Crystallinity

Abstract A vulcanized natural rubber has been deformed in simple extension and in pure shear and the resulting diminution of x-ray intensity of the amorphous halo used as a measure of crystallinity. The effect of mode of deformation and attempts to reach equilibrium states by heat treatment at constant deformation are described. The values obtained for simple extension are in accord with those reported by Goppel and not with those of Field. The degree of crystallinity is greater in pure shear than in simple extension at the same principal extension ratio. Corrected values for the orientation of crystalline regions have been obtained, and a comparison is made between volume changes and x-ray measurements for simple extension.

Digital Filtering and Shape Identification in the Analysis of WAXD Patterns of Semicrystalline Polymers

2013 ◽  
Vol 203-204 ◽  
pp. 189-192 ◽  
Author(s):  
Małgorzata Rabiej
Keyword(s):  
Numerical Differentiation ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Amorphous Halo ◽  
Shape Identification ◽  
Diffraction Curve ◽  
X Ray ◽  
The Degree Of Crystallinity ◽  
Quick Determination

Most frequently, the degree of crystallinity of polymers is determined using Wide Angle X-ray Diffraction (WAXD) technique. The method consists in the resolution of WAXD diffraction curve of a polymer into individual crystalline peaks and amorphous halo. This work presents a procedure, which was elaborated to help in a quick determination of the angular positions of crystalline peaks present in the diffraction curve of investigated polymer. The positions of peaks are determined using numerical differentiation. Using these data the computer program WAXSFIT identifies investigated polymer and prepares a set of starting parameters which are used in the calculations of the degree of crystallinity.

scholarly journals Determination of the Degree of Crystallinity of Poly(2-methyl-2-oxazoline)

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4356
Author(s):  
Evgeniy M. Chistyakov ◽  
Sergey N. Filatov ◽  
Elena A. Sulyanova ◽  
Vladimir V. Volkov
Keyword(s):  
Thermal Destruction ◽  
Polymer Melt ◽  
Boron Trifluoride Etherate ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Cationic Ring Opening Polymerization ◽  
The Degree Of Crystallinity

A new method for purification of 2-methyl-2-oxazoline using citric acid was developed and living cationic ring-opening polymerization of 2-methyl-2-oxazoline was carried out. Polymerization was conducted in acetonitrile using benzyl chloride—boron trifluoride etherate initiating system. According to DSC data, the temperature range of melting of the crystalline phase of the resulting polymer was 95–180 °C. According to small-angle X-ray scattering and wide-angle X-ray diffraction data, the degree of crystallinity of the polymer was 12%. Upon cooling of the polymer melt, the polymer became amorphous. Using thermogravimetric analysis, it was found that the thermal destruction of poly(2-methyl-2-oxazoline) started above 209 °C.

A fitting method for the determination of crystallinity by means of X-ray diffraction

1990 ◽  
Vol 23 (5) ◽  
pp. 359-365 ◽  
Author(s):  
S. Polizzi ◽  
G. Fagherazzi ◽  
A. Benedetti ◽  
M. Battagliarin ◽  
T. Asano
Keyword(s):  
Diffraction Method ◽  
Integral Form ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Acta Cryst ◽  
X Ray ◽  
Amorphous Sample ◽  
Continuous Background ◽  
The Degree Of Crystallinity

A best-fitting version of the X-ray diffraction method of Gehrke & Zachmann [Makromol. Chem. (1981). 182, 627–635] for crystallinity determination, which is a modification of the method developed by Ruland [Acta Cryst. (1961). 14, 1180–1185], is presented. The data, corrected and normalized to electron units (e.u.), are plotted as I(s)s 2 vs s and fitted by pseudo-Voigt functions for the crystalline peaks added to a background scattering IB (s)s 2, with IB (s) = (1 − Xc )I am(s) + Xc 〈f(s)2〉[1 − exp(−ks 2)], where I am is the experimental intensity of a completely amorphous sample (also corrected and normalized to e.u.), 〈f(s)2〉 is the mean square atomic scattering factor in the material, Xc is the degree of crystallinity and k is a factor which includes either thermal or lattice disorder, where s = 2(sin θ)/λ. The use of the scattering of the amorphous sample in this non-integral form of the Ruland equations overcomes the problem, encountered with other procedures, of locating the continuous (background) scattering with accuracy. The degree of crystallinity and the disorder factor are supplied directly by the optimization process. Furthermore, the line broadening analysis which allows the determination of crystallite size is automatically obtained as a by product. Samples of polyethylene terephthalate (PET) with different degrees of crystallinity are investigated. The results are compared with those obtained by other methods which do not use fitting techniques.

X-ray diffraction determination of the degree of crystallinity of cellulose using a computer

1992 ◽  
Vol 24 (1) ◽  
pp. 80-85 ◽  
Author(s):  
A. Sh. Goikhman ◽  
V. M. Irklei ◽  
O. S. Vavrinyuk ◽  
V. I. Pirogov
Keyword(s):  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Determination ◽  
The Degree Of Crystallinity

scholarly journals ASAXS study of CaF2nanoparticles embedded in a silicate glass matrix

2014 ◽  
Vol 47 (1) ◽  
pp. 60-66 ◽  
Author(s):  
Armin Hoell ◽  
Zoltan Varga ◽  
Vikram Singh Raghuwanshi ◽  
Michael Krumrey ◽  
Christian Bocker ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Spatial Distribution ◽  
Glass Matrix ◽  
Structural Parameters ◽  
Pixel Detector ◽  
Oxyfluoride Glass ◽  
X Ray ◽  
X Ray Scattering ◽  
Silicate Glass Matrix

The formation and growth of nanosized CaF2crystallites by heat treatment of an oxyfluoride glass of composition 7.65Na2O–7.69K2O–10.58CaO–12.5CaF2–5.77Al2O3–55.8SiO2(wt%) was investigated using anomalous small-angle X-ray scattering (ASAXS). A recently developed vacuum version of the hybrid pixel detector Pilatus 1M was used for the ASAXS measurements below the CaK-edge of 4038 eV down to 3800 eV. ASAXS investigation allows the determination of structural parameters such as size and size distribution of nanoparticles and characterizes the spatial distribution of the resonant element, Ca. The method reveals quantitatively that the growing CaF2crystallites are surrounded by a shell of lower electron density. This depletion shell of growing thickness hinders and finally limits the growth of CaF2crystallites. Moreover, in samples that were annealed for 10 h and more, additional very small heterogeneities (1.6 nm diameter) were found.

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