Co-crystallization in PEEK Copolymers

1993 ◽  
Vol 5 (4) ◽  
pp. 317-325
Author(s):  
A A Mehmet-Alkant ◽  
J N Hayt ◽  
D J Blundell ◽  
D G Parker
Keyword(s):  
Diphenyl Ether ◽  
Degree Of Crystallinity ◽  
Wide Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
Low Levels ◽  
The Degree Of Crystallinity ◽  
Comonomer Content

Thermal and wide-angle x-ray scattering (wAxs) studies of a new set of copolymers of polyether ether ketone (PEEK) with ether diphenyl ether ketone (EDEK) have been undertaken. The copolymerization modifies the properties of PEEK. At low levels of comonomer content the incorporation of the comonomer unit lowers the melting temperature and reduces the degree of crystallinity. At higher levels the melting point increases towards that of the PEDEK homopolymer. The x-ray structure is very similar to that of PEEK, consistent with rejection of the comonomer at low levels of comonomer content. At high levels the structure is very similar to that of PEDEK while at intermediate levels the structure is found to 'swtich' from that of PEEK to that of PEDEK, consistent with co-crystallization of the two monomer units.

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.

Poly(Ethylene Oxide)/Styrene Ionomers Blends: Crystallization of Poly (Ethylene Oxide) Component Studied by Wide-Angle X-Ray Diffraction

2007 ◽  
Vol 130 ◽  
pp. 251-256 ◽  
Author(s):  
Czesław Ślusarczyk ◽  
Kazimiera Suchocka-Gałaś
Keyword(s):  
Ethylene Oxide ◽  
Degree Of Crystallinity ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Component ◽  
Ionic Groups ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
The Degree Of Crystallinity

Wide-angle X-ray diffraction (WAXD) and the scanning electron microscopy (SEM) were used to determine the morphology of crystalline phase of blends of poly(ethylene-oxide) (PEO) and styrene-acrylic acid (S-AA) copolymers neutralized with sodium ions (Na+). In this study, we investigated the effects of blend composition and the content of ionic groups in amorphous ionomers on the degree of crystallinity and the crystallite sizes. It was found that the degree of crystallinity of PEO in the blends decreases both with increasing S-ANa(6.4) content and with increasing ANa content. The sizes of PEO crystallites, measured both in the direction perpendicular and parallel to the polymer axis, are almost independent of ionic groups content in the amorphous component of the blends but they decrease with increasing S-ANa(6.4) content. For the blends containing small amounts of PEO the confined crystallization of this polymer were observed. The final crystalline morphology of these blends, observed by SEM method, is different in comparison to that formed without spatial confinement.

CONNECTION BETWEEN STRUCTURAL CHANGES OF IRRIADIATED POLYETHER ETHER KETONE AND MECHANICAL PROPERTIES

Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 95-101
Author(s):  
Aneta NIEMIEC
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Structural Changes ◽  
Radiation Energy ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
The Impact ◽  
The Degree Of Crystallinity

The article presents the results of research on the impact of structural changes in polyether ether ketone (PEEK) on its mechanical properties. The polymer was exposed to gamma radiation at a dose of 50 and 150 kGy, and the radiation energy was 4 MeV. Changes in the degree of crystallinity and the related changes in the glass transition and melting temperature for the polymer were determined by differential scanning calorimetry (DSC). Mechanical properties were determined using the micro-mentoring method. The tests showed a change in the degree of crystallinity in the range of several degrees and a significant increase in the glass transition temperature. In terms of mechanical properties, the reduction of hardness and Young’s modulus was observed. Observed changes, especially in terms of changes in the structure of the polymer under the influence of radiation, are difficult to explain, which requires conducting further research, especially in the range of irradiation parameters used. Further research is important because PEEK is used in many fields, especially in conditions conducive to corrosion and the influence of radiation.

New Insight of Isothermal Melt Crystallization in Poly(aryl ether ether ketone) via Time-Resolved Simultaneous Small-Angle X-ray Scattering/Wide-Angle X-ray Diffraction Measurements

1995 ◽  
Vol 28 (20) ◽  
pp. 6931-6936 ◽  
Author(s):  
Benjamin S. Hsiao ◽  
Bryan B. Sauer ◽  
Ravi K. Verma ◽  
H. Gerhard Zachmann ◽  
Soenke Seifert ◽  
...  
Keyword(s):  
Small Angle ◽  
Wide Angle ◽  
Melt Crystallization ◽  
Aryl Ether ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ether Ether Ketone ◽  
Ether Ketone

Differential scanning calorimetry/small-angle X-ray scattering analysis of ultraviolet sensible polypropylene filaments

2021 ◽  
pp. 004051752110533
Author(s):  
Martina Vikova ◽  
Shinichi Sakurai ◽  
Aravin Prince Periyasamy ◽  
Hidekazu Yasunaga ◽  
Miroslava Pechočiaková ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Pigment Concentration ◽  
Degree Of Crystallinity ◽  
Lamellar Thickness ◽  
Drawing Ratio ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
The Degree Of Crystallinity ◽  
Ray Scattering

In this work, ultraviolet (UV) sensible metallocene isotactic polypropylene (miPP) filaments were produced with different drawing ratios and various concentrations of photochromic pigment. The effects of pigment concentration and drawing ratio on the chromatic properties and the structural modification for the miPP filaments were studied extensively by differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS/WAXS) measurements. The change in melting temperature and the polymeric structures, such as lamellar thickness, long period and degree of crystallinity of miPP with the addition of a UV sensible pigment into miPP and the drawing process, were evaluated. The results show that the pigment concentration and the drawing ratio influence the inner structure of miPP filaments. Finally, our investigation shows that SAXS and also WAXS are appropriate to determine the lamellar thickness and the degree of crystallinity established by the DSC approach. This work attempts to correlate the results of lamellar thickness, the degree of crystallinity and the higher-order structure of the polymer acquired by DSC as well as X-ray diffraction (XRD) techniques in order to develop an appropriate approach to find the influence of pigment concentration and drawing ratio on miPP filaments.

The Influence of Plastic Deformation on Structure of Highly Crosslinked UHMWPE Intended for Endoprosthesis Cups

2013 ◽  
Vol 197 ◽  
pp. 13-18
Author(s):  
Joanna Maszybrocka ◽  
Jerzy Cybo ◽  
Jan Cwajna ◽  
Adrian Barylski ◽  
Piotr Czaja
Keyword(s):  
Plastic Deformation ◽  
Functional Properties ◽  
Small Angle ◽  
Lamellar Structure ◽  
Axial Ratio ◽  
Degree Of Crystallinity ◽  
Cross Linking ◽  
X Ray ◽  
X Ray Scattering ◽  
The Degree Of Crystallinity

In this paper, an attempt has been made to determine the changes in the structure of UHMWPE under the influence of deformation, which can be the cause of the decrease of functional properties. It has been found that the degree of cross-linking slightly changes due to operational loads (deformation ef=0.15-0.6). The deformation leads, however, to the systematic lowering of the degree of crystallinity and an insignificant decrease of lamella width. Tests of wide- and small-angle X-ray scattering (WAXS, SAXS) prove that this is the result of operational deformation causing a rather weak texture of crystals and the fragmentation of some lamellae. Anisotropy of the lamellar structure also takes place, which changes 2D SAXS images into ellipses with a rapidly growing axial ratio with ef value.

Crystallite dimensions - characterization of ethene-/ɑ-olefin Copolymers with various comonomers and comonomer Ccontents measured by small- and wide angle X-ray scattering

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Florian J. Stadler ◽  
Tatsuhiro Takahashi ◽  
Koichiro Yonetake
Keyword(s):  
Crystallite Size ◽  
Average Distance ◽  
Wide Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
Lamella Thickness ◽  
Comonomer Content ◽  
Ray Scattering

AbstractEthene-/ɑ-olefin copolymers having a wide range of comonomer contents and comonomers between 4 and 26 carbon atoms in length were characterized by wide angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS). The data was evaluated with respect to the crystallite size. The half-width of the main crystallite peaks was transformed into the crystallite size s110 and s200 using the Scherrer equation. It was found to decrease with increasing comonomer content. The crystal lamella thickness was determined from the long period and the crystallinity of the samples. The crystal lamella thickness was found to decrease with decreasing crystallinity following a 3rd order polynomial. This means that the introduction of SCBs leads to a decrease of the crystallite size. A higher Mwleads to an increase of the lamella size in comparison to lower molecular samples with the same crystallinity. The lamella thickness is limited by the average distance between two short-chain branches which is dependent on the comonomer content.

Investigation of the Crystallization of Polyetherketones by the Differential Scanning Calorimetry Method

2018 ◽  
Vol 935 ◽  
pp. 36-39 ◽  
Author(s):  
Azamat A. Zhansitov ◽  
Azamat L. Slonov ◽  
Arthur E. Baikaziev ◽  
Marina M. Murzakanova ◽  
S.Yu. Khashirova
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Phase Transitions ◽  
Crystallization Temperature ◽  
Amorphous Structure ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
The Degree Of Crystallinity

Differential scanning calorimetry was used to study the temperatures and character of phase transitions of fibers based on polyether ether ketones. It is shown that in the production of fine fibers from polyether ether ketones, a predominantly amorphous structure is formed. Increasing the temperature to the crystallization temperature leads to an almost twofold increase in the degree of crystallinity. Lower molecular weight polyether ether ketone is characterized by a higher rate of crystallization and the formation of a more homogeneous crystalline structure.

Combined small- and wide-angle X-ray scattering study of early stages of polymer crystallization

2003 ◽  
Vol 36 (4) ◽  
pp. 991-994 ◽  
Author(s):  
P. Panine ◽  
V. Urban ◽  
P. Boesecke ◽  
T. Narayanan
Keyword(s):  
Single Photon ◽  
Early Stage ◽  
Onset Time ◽  
Degree Of Crystallinity ◽  
Photon Flux ◽  
Wide Angle ◽  
X Ray ◽  
Early Stages ◽  
X Ray Scattering ◽  
Ray Scattering

The early stage of melt crystallization in low-density polyethylene was investigated by simultaneous time-resolved small-angle and wide-angle X-ray scattering (SAXS/WAXS) techniques. The high detectivity of the two-dimensional detectors together with the large photon flux of an undulator source permitted the collection of SAXS and WAXS patterns with nearly single-photon sensitivity and sub-second time resolution. As a result, the crystalline fraction well below 0.001 can be reliably detected and the apparent induction time is considerably reduced (<10 s). The time evolution of both the SAXS invariant and the degree of crystallinity follow the well established Avrami-type growth law. Despite the orders of magnitude improvement in sensitivity, the difference in the onset time of SAXS and WAXS signals is not significant. The behaviour of the SAXS data in the very early stages is not consistent with spinodal decomposition mechanism as described by the linearized Cahn–Hilliard theory.

Sign in / Sign up

Export Citation Format

Share Document