scholarly journals Rheo-Optical Studies on the Deformation Mechanism of Semicrystalline Polymers. XII. On the Nature of Alpha and Beta Mechanical Dispersions of High-Density Polyethylene in Relation to the Mechanism of Spherulite Deformation

1980 ◽  
Vol 12 (11) ◽  
pp. 809-834 ◽  
Author(s):  
Thein Kyu ◽  
Masayuki Yamada ◽  
Shoji Suehiro ◽  
Hiromichi Kawai
Keyword(s):  
Deformation Mechanism ◽  
High Density Polyethylene ◽  
Semicrystalline Polymers ◽  
High Density ◽  
Optical Studies

Quantification of Cavitation in Neat and Calcium Carbonate-Filled High-Density Polyethylene Subjected to Tension

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
F. Addiego ◽  
J. Di Martino ◽  
D. Ruch ◽  
A. Dahoun ◽  
O. Godard ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
High Density Polyethylene ◽  
Shape Factor ◽  
Tensile Deformation ◽  
Quantitative Information ◽  
Semicrystalline Polymers ◽  
High Density ◽  
Deformation State ◽  
Microscopic Features ◽  
Void Shape

Cavitation-induced deformation mechanisms in neat semicrystalline polymers, i.e., crazing, and in the derived composites, i.e., particle-matrix debonding, are generally activated during the transition between viscoelastic and viscoplastic deformation stages. However, little quantitative information about the void evolution with the drawing level is to date available in the literature. The objective of this work is to quantify cavitation mechanisms in neat and calcium carbonate-filled high-density polyethylene (HDPE) subjected to tensile deformation. Attention was first focused on the properties of the materials that were assessed by means of a thermogravimetric analyzer, a differential scanning calorimeter, a scanning electron microscope (SEM), and a dynamic mechanical analyzer. In a second step, macroscopic aspects of cavitation were studied by quantifying volume variation of the materials subjected to tension using an accurate optical extensometer (VidéoTraction). Attention was then turned to microscopic features of cavitation through a careful quantification of void density and shape factor by means of a method coupling a SEM with an image analysis procedure. At the two scales of interest, the results demonstrate that (i) the void density generated by crazing in neat HDPE or particle-matrix debonding in the composites gradually increases with the deformation state, (ii) void density induced by debonding is higher than that generated by crazing, and (iii) decreasing particles size causes an increase of void density. We also estimated the void shape factor, that is, ratio between the height and the width of the cavities. In all the studied materials, this parameter starts from a value that is below 1 and increases by a factor of 2 with increasing deformation. Moreover, in the case of the composites, one notes a higher void shape factor compared with the neat material, and particle size does not influence this parameter. The results provided by this paper can be the basis of a physically based model predicting cavitation mechanisms in semicrystalline polymers.

scholarly journals Deformation mechanism of high-density polyethylene probed by in situ Raman spectroscopy

Polymer ◽  
2015 ◽  
Vol 58 ◽  
pp. 88-95 ◽  
Author(s):  
Takumitsu Kida ◽  
Tatsuya Oku ◽  
Yusuke Hiejima ◽  
Koh-hei Nitta
Keyword(s):  
Raman Spectroscopy ◽  
Deformation Mechanism ◽  
High Density Polyethylene ◽  
High Density ◽  
In Situ Raman Spectroscopy ◽  
In Situ Raman
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