Strain-Induced Crystallization and Conformational Transition of Poly(trimethylene terephthalate) Films during Uniaxial Deformation Probed by Polarized Infrared Spectroscopy

2013 ◽  
Vol 52 (35) ◽  
pp. 12596-12603 ◽  
Author(s):  
Nadarajah Vasanthan ◽  
Naga Jyothi Manne
2008 ◽  
Vol 81 (5) ◽  
pp. 753-766 ◽  
Author(s):  
Sureerut Amnuaypornsri ◽  
Jitladda Sakdapipanich ◽  
Shigeyuki Toki ◽  
Benjamin S. Hsiao ◽  
Naoya Ichikawa ◽  
...  

Abstract The effects of proteins and phospholipids in natural rubber (NR) on the strain-induced crystallization behavior during uniaxial deformation were studied by in-situ synchrotron wide-angle X-ray diffraction (WAXD) technique and simultaneous measurements of stress-strain relation. The influences of proteins and phospholipids in NR were evaluated separately by decomposition methods using deproteinization and lipase treatment, respectively. It was found that both components form a naturally occurring network, which is responsible for the strain-induced crystallizability of unvulcanized NR and the corresponding high mechanical property. This network also plays a significant role in strain-induced crystallization of vulcanized natural rubber.


RSC Advances ◽  
2015 ◽  
Vol 5 (32) ◽  
pp. 25171-25182 ◽  
Author(s):  
Xuan Fu ◽  
Guangsu Huang ◽  
Zhengtian Xie ◽  
Wang Xing

The existence of a denser network domain formed by incorporation of filler and its vital role in determining the strain-induced crystallization behavior of nanocomposites is proved by in situ synchrotron X-ray diffraction characterization.


Author(s):  
Gaurav Mago ◽  
Jerry A. Dutreuil ◽  
Frank T. Fisher ◽  
Dilhan M. Kalyon

The goal of this investigation is to elucidate the interrelations between the strain-induced crystallization behavior, morphology and mechanical properties of poly (butylene terephthalate) PBT and its nanocomposites with multi-walled carbon nanotubes (MWNTs). The mechanical properties of semicrystalline polymers such as PBT depend upon the processing conditions, which affect the crystallization behavior and the resulting crystal morphology developed within the processed sample. PBT is observed to undergo strain-induced crystallization during uniaxial deformation, with concomitant changes in the polymer crystal as a function of the applied strain history. In the current work polymer morphology was investigated with wide angle XRD, differential scanning calorimetry (DSC) and polarized light microscopy (PLM). DSC results indicate an increase in crystallinity due to strain-induced crystallization during uniaxial cold-stretching, which was further confirmed with XRD analysis of the samples. Analyses of the samples under polarized light pre- and post-stretching clearly show that there is a transformation of the spherulitic crystals of the pre-stretch morphology into elongated oblong crystals, as the imposed strain exceeds a critical value. Annealing of PBT was done under different conditions to probe the effects of changes in the crystallinity obtained upon thermal treatment on polymer morphology and mechanical properties. The annealed samples were found to have high crystallinity, high Young’s modulus, and low yield stress values as compared to unannealed samples processed under similar conditions. To investigate the effects of nanoparticle loadings on PBT crystal morphology and mechanical properties, pure PBT was melt mixed with different concentrations of multi-walled carbon nanotubes (MWNTs). Due to the increased nucleation rate effect associated with the incorporation of MWNTs, the PBT crystallization temperature was increased and the crystal size decreased with the increasing concentration of MWNTs. Tensile tests performed on PBT and their nanocomposite samples revealed decreases in the elongation at break values. Research is ongoing to understand the relationship between the MWNT loading levels and mechanical properties along with study of orientation of MWNTs under tensile load and its effect on strain-induced crystallization.


Soft Matter ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 447-455 ◽  
Author(s):  
Pinzhang Chen ◽  
Yuanfei Lin ◽  
Jingyun Zhao ◽  
Lingpu Meng ◽  
Daoliang Wang ◽  
...  

Micro-structural evolution of polybutadiene rubber in strain-temperature space, and the reconstruction of the macro-mechanical response.


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