Study, by Raman Spectroscopy, of the microstructure evolution of isotactic polypropylene during tensile test and relaxation: Measuring the chains orientation

2011 ◽  
Author(s):  
S. Chaudemanche ◽  
M. Ponçot ◽  
J. Martin ◽  
J. M. Hiver ◽  
P. Bourson ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Tensile Test ◽  
Isotactic Polypropylene ◽  
Microstructure Evolution

scholarly journals Microstructure evolution of isotactic polypropylene during annealing: Effect of poly(ethylene oxide)

2012 ◽  
Vol 30 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Hai-yan Wu ◽  
Xiao-xi Li ◽  
Fang-ming Xiang ◽  
Ting Huang ◽  
Yun-yun Shi ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Isotactic Polypropylene ◽  
Microstructure Evolution ◽  
Annealing Effect ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

scholarly journals Raman Spectroscopy of Isotactic Polypropylene-Halloysite Nanocomposites

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Elamin E. Ibrahim ◽  
Dorina Magdalena Chipara ◽  
Ram Thapa ◽  
Karen Lozano ◽  
Mircea Chipara
Keyword(s):  
Raman Spectroscopy ◽  
Detailed Analysis ◽  
Isotactic Polypropylene ◽  
Thermal Processing ◽  
Polymeric Matrix

Raman spectroscopy investigations on nanocomposites obtained by dispersing halloysite within isotactic polypropylene are reported. A detailed analysis of the modifications of the regularity band associated to the polymeric matrix is presented. The Raman lines assigned to the polymeric matrix are broadened and weakened as the loading with halloysite is increased. The analysis of Raman lines indicates that the polymeric matrix becomes less crystalline upon the loading with halloysite and that the nanofiller is experiencing a weak dehydration upon dispersion within the polymeric matrix, probably due to the related thermal processing used to achieve the dispersion of halloysite.

The β-Spherulite Morphology of Isotactic Polypropylene Investigated by Raman Spectroscopy

2009 ◽  
Vol 63 (12) ◽  
pp. 1377-1381 ◽  
Author(s):  
J. Martin ◽  
P. Bourson ◽  
A. Dahoun ◽  
J. M. Hiver
Keyword(s):  
Raman Spectroscopy ◽  
Isotactic Polypropylene ◽  
Spherulite Morphology

scholarly journals Effects of Solid-State Stretching on Microstructure Evolution and Physical Properties of Isotactic Polypropylene Sheets

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 618 ◽  
Author(s):  
Huajian Ji ◽  
Xulin Zhou ◽  
Xin Chen ◽  
Haili Zhao ◽  
Yu Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Yield Point ◽  
Isotactic Polypropylene ◽  
Microstructure Evolution ◽  
Crystal Size ◽  
Crystal Morphology ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering

The microstructure evolution of an isotactic polypropylene (iPP) sheet during solid-state stretching was studied. The transition of the spherulites—cylindrites was evaluated using in-situ two-dimensional wide-angle and small-angle X-ray scattering methods. The crystallinity of stretched iPP sheets was characterized by differential scanning calorimetry. The crystal morphology was observed by means of scanning electron microscopy. It was found that the differences of crystal microstructure of the iPP sheet depended on the stretching strain, which promoted the orientation of molecular chains. Amorphous molecular chains in the spherulites oriented and formed into a mesophase near the yield point, and the partially ordered mesophase was further stretched to form an oriented cylindrite structure after the yield point. The highest relative content of cylindrites appeared at 15% strain. Notably, as the amorphous phase embedded into the lamellae layer, the crystal size decreased with the increase of strain, which indicated that the crystallinity of the stretched iPP sheet was much higher than that of unstretched iPP sheet. The induced cylindrites structure played a more important role in improving the mechanical properties and heat resistance of iPP sheets. Compared with the unstretched iPP sheets, the tensile strength increased by 28%, the notch impact toughness significantly increased by 78%, and the vicat softening point increased from 104 to 112 °C.

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