Toughening of polybutene-1 with form I′ induced by rapid pressurization

CrystEngComm ◽  
2021 ◽  
Author(s):  
Yanping Liu ◽  
Yingchao Wang ◽  
Hongyu Zhang ◽  
Yuewen Wu ◽  
Shuo Zhao ◽  
...  

Combined with in situ wide angle X-ray diffraction, the mechanical properties of polybutene-1 with rapid pressurization are investigated. The toughness of polybutene-1 can be improved significantly by forms I/I′ produced by rapid pressurization.

Carbon ◽  
2015 ◽  
Vol 87 ◽  
pp. 246-256 ◽  
Author(s):  
Périne Landois ◽  
Mathieu Pinault ◽  
Stéphan Rouzière ◽  
Dominique Porterat ◽  
Cristian Mocuta ◽  
...  

2010 ◽  
Vol 113-116 ◽  
pp. 1712-1715
Author(s):  
Cheng Yu Wang ◽  
Chang Yu Liu ◽  
Jian Li

The preparation of hydrophobic CaCO3-wood composite through a double-diffusive method using dodecanoic acid as organic substrate is demonstrated. The product was characterized by the contact angle analysis, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The mechanical properties of the product were measured. The results show that the synthesized CaCO3 fills in the wood cell and covers the surface of wood. The CaCO3-wood composite is hydrophobic. The mechanical properties of wood composite have significantly increased.


2015 ◽  
Vol 1754 ◽  
pp. 13-18 ◽  
Author(s):  
Michael Behr ◽  
James Rix ◽  
Brian Landes ◽  
Bryan Barton ◽  
Eric Hukkanen ◽  
...  

ABSTRACTThis paper will discuss the structure-property model developed that correlates the tensile modulus to the elastic properties and angular distribution of constituent graphitic layers for carbon fiber derived from a polyethylene precursor. In addition, a high-temperature fiber tensile device was built to enable heating of carbon fiber bundles at a variable rate from 25 °C to greater than ∼2300 °C, while simultaneously applying a tensile stress. This capability combined with synchrotron wide-angle x-ray diffraction (WAXD), enabled observation in situ and in real time of the microstructural transformation from different carbon fiber precursors to high-modulus carbon fiber. Experiments conducted using PAN- and PE-derived fiber precursors reveal stark differences in their carbonization and high-temperature graphitization behavior.


2007 ◽  
Vol 124-126 ◽  
pp. 1083-1086
Author(s):  
Jun Hee Sung ◽  
Hyoung Jin Choi

Nanocomposites of conducting polymers of polyaniline (PANI), poly(oethoxyaniline) (PEOA) and polypyrrole (PPy) with clay prepared via either in-situ emulsion polymerization or solvent intercalation were investigated especially for electrorheological fluid (ER) application. Internal structures of these nanocomposites were examined via wide angle X-ray diffraction (WAXD), and transmission electron microscope (TEM). The intercalated nanostructures analyzed via WAXD and TEM were correlated with the electrical property change originated from the nanoscale interaction between clay and conducting polymer. Moreover, their ER behaviors were measured via rotational rheometer with external electric field controller.


2015 ◽  
Vol 88 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Rouhollah Bagheri ◽  
Reza Darvishi

ABSTRACT In this study, polyurethane (PU)/organomodified montmorillonite (cloisite®30B) is synthesized via in situ polymerization by reaction of an ether-based prepolymer with the isocyanate end groups and adiamine chain extender (4, 4-methylene-bis(2-chloroaniline)) in the presence of different amounts of nanoparticles dispersed in the prepolymer matrix by an ultrasonic mixer for 1 h. The synthesized polymers are cast on a pretreated carbon steel sheet and cured at 120 °C in an oven. The PU and its composites have been characterized by using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and mechanical testing. The XRD analysis of the cured samples containing 1 to 3 wt% cloisite30B showed intercalation segments in the silicate layers and exfoliation for 0.5 wt% nanoparticles. The highest mechanical properties were obtained using the cured exfoliated silicate layer sample. A twofold increase in the ultimate tensile strength and a 2.3 times increase in the adhesion strength were found for 0.5 wt% organoclay/PU as compared with that of pure PU. In addition, the exfoliated structure sample exhibited a 16% reduction in abrasion compared with that of pure PU.


2013 ◽  
Vol 821-822 ◽  
pp. 23-27
Author(s):  
Xiang Li ◽  
Chun Yi Liu ◽  
Ai Wen Qin ◽  
Xin Zhen Zhao ◽  
Chun Ju He

Plasticized polyacrylonitrile(PAN) fibers have been chemically impregnated with aqueous solution of KMnO4under varying conditions of temperature and time. The effect of modification conditions on the chemical structure and the mechanical properties of precursor fibers are characterized by wide-angle X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. The experimental results show that KMnO4can be used not only as catalyst for cyclization reaction, but also as plasticizer. The chemical modification between KMnO4and PAN can not occur below70°C, the most suitable condition for modification is performed at 80°C for 5 min.


2016 ◽  
Vol 29 (10) ◽  
pp. 1158-1164 ◽  
Author(s):  
Yiran Zhou ◽  
Xu Han ◽  
Xiaoyuan Hu ◽  
Lianghua Xu ◽  
Weiyu Cao

Evolution of the orientation structures of polyacrylonitrile (PAN) precursors during thermal stabilization was investigated on the basis of in situ temperature-dependent measurements including synchrotron wide-angle X-ray diffraction and polarized infrared spectroscopy. The results indicated that the Hermans orientation factor of PAN crystallites increased firstly and then decreased in the process of stabilization, while the orientation of molecular chains showed a two-stage decrease. These were mainly attributed to the thermal relaxation of molecular chains and the cyclization reactions, which also resulted in the physical shrinkage as well as the chemical shrinkage apparently observed from the thermal mechanical curves of the precursor.


1988 ◽  
Vol 134 ◽  
Author(s):  
Seiichi Mukai ◽  
S. Nozawa ◽  
M. Kimura ◽  
T. Tayama

ABSTRACTA novel polyimide-based heterocyclic polymer, polyimide benzobisthiazole (PIBT), was prepared from diaminophenylene benzobisthiazole (DAPBT) and pyromellitic acid dianhydride (PMDA). Fibers with tensile modulus of 220 GPa were obtained from PIBT; this modulus value is consistent with the 430 GPa modulus determined by wide-angle x-ray diffraction (WAXD) analysis. Unoriented isotropic films exhibited significantly lower modulus values in the range of 10 GPa. Block copolymers of PIBT with thermoplastic segments were synthesized in an effort to prepare molecular composites. These materials showed a dramatic decrease in melt viscosity and had modulus values lower than observed in isotropic PIBT films.


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