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.

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.

Study of the Effect of Processing Cycles on the Thermophysical Properties of Polyether Ether Ketone

2018 ◽  
Vol 935 ◽  
pp. 40-44 ◽  
Author(s):  
Azamat A. Zhansitov ◽  
Albert S. Shabaev ◽  
K.T. Shakhmurzova ◽  
Zh.I. Kurdanova ◽  
Rustam M. Mamkhegov ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Thermophysical Properties ◽  
Degradation Products ◽  
Scanning Calorimetry ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
Decomposition Schemes ◽  
Melting And Crystallization

The effect of heating cycles of polyether ether ketone up to 420 °C on the thermophysical properties was studied by the method of differential-scanning calorimetry. It is shown that with each subsequent heating the glass transition temperature increases, while the melting and crystallization temperature decreases, which may indicate an increase in the molecular weight of the polymer due to the structuring processes. The main degradation products of polyether ether ketone in air at temperatures of 350-450 °C were determined by gas chromatography and thermal decomposition schemes were proposed.

Study of the structure and thermal characteristics of nanocomposites based on polyvinyl alcohol and intercalated montmorillonite

2019 ◽  
pp. 089270571987919
Author(s):  
Volodymyr Krasinskyi ◽  
Ivan Gajdos ◽  
Oleh Suberlyak ◽  
Viktoria Antoniuk ◽  
Tomasz Jachowicz
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Acrylic Acid ◽  
Polyvinyl Alcohol ◽  
Thermal Characteristics ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Degree Of Crystallinity

The structure and thermal characteristics of nanocomposites based on polyvinyl alcohol (PVA) and montmorillonite (MMT) intercalated with polyvinylpyrrolidone were investigated by X-ray diffraction analysis and differential scanning calorimetry. The modification of PVA with intercalated MMT reduces the degree of crystallinity of the resulting nanocomposites but significantly increases their thermal stability. Under ultrasound, the intercalated MMT was completely distributed in a PVA solution and formed a monocrystalline structure. Films based on PVA with modified MMT were cross-linked at 110°C in the presence of 5 wt% acrylic acid and 0.5 wt% Ferrous(II) sulfate as an initiator. The formed films have a homogeneous cross-linked structure.

scholarly journals Crystallinity of Electrospun and Centrifugal Spun Polycaprolactone Fibers: A Comparative Study

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Eva Kuzelova Kostakova ◽  
Laszlo Meszaros ◽  
Gabriela Maskova ◽  
Lenka Blazkova ◽  
Tamas Turcsan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Production Technology ◽  
Average Molecular Weight ◽  
Degree Of Crystallinity ◽  
Fibrous Materials ◽  
Scanning Calorimetry ◽  
Crystallinity Degree ◽  
A Minor ◽  
Technology Effects ◽  
The Degree Of Crystallinity

Crystalline properties of semicrystalline polymers are very important parameters that can influence the application area. The internal structure, like the mentioned crystalline properties, of polymers can be influenced by the production technology itself and by changing technology parameters. The present work is devoted to testing of electrospun and centrifugal spun fibrous and nanofibrous materials and compare them to foils and granules made from the same raw polymer. The test setup reveals the structural differences caused by the production technology. Effects of average molecular weight are also exhibited. The applied biodegradable and biocompatible polymer is polycaprolactone (PCL) as it is a widespread material for medical purposes. The crystallinity of PCL has significant effect on rate of degradation that is an important parameter for a biodegradable material and determines the applicability. The results of differential scanning calorimetry (DSC) showed that, at the degree of crystallinity, there is a minor difference between the electrospun and centrifugal spun fibrous materials. However, the significant influence of polymer molecular weight was exhibited. The morphology of the fibrous materials, represented by fiber diameter, also did not demonstrate any connection to final measured crystallinity degree of the tested materials.

Investigation of Nonisothermal Crystallization Behaviors of Poly and Silica Nanocomposites Using Differential Scanning Calorimetry

2005 ◽  
Vol 295-296 ◽  
pp. 39-44 ◽  
Author(s):  
Ling Xue Kong ◽  
Z. Peng
Keyword(s):  
Differential Scanning Calorimetry ◽  
Cooling Rate ◽  
Crystallization Temperature ◽  
Self Assembly ◽  
Degree Of Crystallinity ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Crystallization Behaviors ◽  
Silica Nanocomposites

Nonisothermal crystallization behaviors of PVA and poly (vinyl alcohol) and Silica (PVA/SiO2) nanocomposites prepared via a self-assembly monolayer (SAM) technique are investigated in this study. Differential scanning calorimetry (DSC) is used to measure the crystallization temperature and enthalpy of PVA and nanocomposites in nitrogen at various cooling rate. The results show that the degree of crystallinity of PVA and nanocomposites decreases when the SiO2 content increases but increases with an increasing cooling rate. The peak crystallization temperature decreases with an increasing cooling rate.

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.

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.

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