Crystal forms and phase transformation of 1,5-pentanediamine-terephthalate: a bio-based nylon 5T monomer

2020 ◽  
Vol 76 (4) ◽  
pp. 524-533
Author(s):  
Zihan Li ◽  
Pengpeng Yang ◽  
Haodong Liu ◽  
Jun Liu ◽  
Sha Zhu ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Water Activity ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Phase Form ◽  
Crystal Forms ◽  
X Ray ◽  
Thermodynamic Conditions ◽  
Biomass Resources

Nylon 5T is one of the bio-based nylons, its raw material 1,5-pentanediamine is derived from biomass resources and produced by biological methods. 1,5-pentanediamine-terephthalate (PDA-TPA) is the monomeric salt for nylon 5T polymerization, and its own product quality has a significant impact on the performance of nylon 5T. PDA-TPA was prepared by anti-solvent crystallization in this study. It exists in two solid forms, a monohydrate [form (I)] and an anhydrous phase [form (II)]. The transition temperature of the two phases was around 65°C in the given ethanol–water binary (7:1) mixture. The characterization of monohydrate and anhydrate phases regarding structures and stabilities was carefully carried out using powder X-ray diffraction, single crystal X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, hot-stage microscopy and Fourier transform infrared spectroscopy. The relationship between the molecular interactions of monohydrate and anhydrate phases under different packing architectures and their thermal behaviours was analysed and established. In addition, the relationships between the structures and thermal behaviours for the two solid forms were analysed and established. In addition, the effect of solvent on phase conversion, the relationships between the temperature and water activity, as well as the relative stability of monohydrate and anhydrate phases under different thermodynamic conditions, were investigated by solid–solid transformation and solvent-mediated transformation experiments. It was obvious that the transition temperature of monohydrate and anhydrate phases of PDA-TPA was significantly influenced by water activity, and the larger the value of water activity is, the higher is the transition temperature. These studies give insight into the transformation of nylon 5T monomer salt and contribute to the control of target crystal preparation.

Influence of Gd Addition on the Structure and Capability of Ni-Mn-In Metamagnetic Shape Memory Alloys

2012 ◽  
Vol 535-537 ◽  
pp. 950-953
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Zhi Jian Duan ◽  
Jian Jun Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Transition Temperature ◽  
Martensitic Transformation ◽  
Room Temperature ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It is Observed through the experiment: the addition of Gd enhances martensite transition temperature;X-ray diffraction analysis of experimental alloys is revealed that to the mixture is martensite and austenite at room temperature; content of Gd is not proportional to the improvement of magnetic property.

Morphology Control of the Nano-MnO2 by Microwave Hydrothermal Synthesis

2012 ◽  
Vol 624 ◽  
pp. 47-50
Author(s):  
Shi Lei Zhang ◽  
Ben Niu ◽  
Enlei Qi ◽  
Lei Wang ◽  
Jie Qiang Wang
Keyword(s):  
Hydrothermal Synthesis ◽  
Energy Dispersive Spectrometer ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Microwave Assisted ◽  
Structure And Morphology ◽  
Microwave Hydrothermal ◽  
Scanning Electron

In this paper, KMnO4 was used as raw material, nano-MnO2 with different morphologies such as flowers globular, hollow tubular and rodlike were obtained by the microwave assisted hydrothermal synthesis under the acidic condition. The crystal structure and morphology of the resultant MnO2 were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM), respectively. The elements and content of samples were tested by Energy Dispersive Spectrometer (EDS). The influence of reaction temperature and holding time on crystal forms and morphologies of the MnO2 was analyzed.

The Crystal Structures at 10 K of the Trigonal Salts KMIII(NH3)6(ClO4)2Cl2, MIII = Os and Cr, and the Possibility of Phase Transitions

1999 ◽  
Vol 52 (3) ◽  
pp. 219 ◽  
Author(s):  
Philip A. Reynolds ◽  
Brian N. Figgis ◽  
Alexander N. Sobolev
Keyword(s):  
Differential Scanning Calorimetry ◽  
Transition Temperature ◽  
Crystal Structures ◽  
Low Temperatures ◽  
Simple Structure ◽  
Alkali Metal Cations ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Threefold Axis ◽  
X Ray

The crystal structures of KOs(NH3)3(ClO4)2Cl2 and KCr(NH3)6(ClO4)2Cl2 were determined at 10 K by X-ray diffraction, and for the osmium salt also at 293 K. At 293 K the osmium salt is trigonal, space group R 3m, with the same simple structure as others of this class of double salt. At 10 K, in agreement with previous radius ratio predictions, both crystals are best described as remaining R 3m. All previously studied members, with larger alkali metal cations, are twinned R 3 at low temperatures, with small, symmetry-breaking rotations of the hexaamminemetal(III) and perchlorate ions about the threefold axis. Differential scanning calorimetry on CsRu(NH3)6(ClO4)2Cl2 suggests that the R 3m to R 3 change is very extended in temperature with only a small discontinuity at the transition temperature.

scholarly journals Phase, Microstructure, Thermochromic, and Thermophysical Analyses of Hydrothermally Synthesized W-Doped VO2 Nanopowder

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Hamdi Muhyuddin Barra ◽  
Soo Kien Chen ◽  
Nizam Tamchek ◽  
Zainal Abidin Talib ◽  
Oon Jew Lee ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Thermophysical Properties ◽  
Vanadium Dioxide ◽  
X Ray Diffraction ◽  
Abrupt Increase ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Commercial Use ◽  
Elemental Doping ◽  
W Doping

Vanadium dioxide (VO2) has great potential as an intelligent architectural glazing system as it can control the amount of light, heat, and solar energy relative to the temperature in the environment. However, the applicability of VO2 for commercial use is yet to be realized because its phase transition temperature (τc) of ∼68°C is too high for use in buildings. A proven strategy to lower its τc is by elemental doping. Hence, in this study, hydrothermal synthesis of nanostructured VO2 was carried out with the introduction of tungsten (W) as a dopant. Furthermore, the effects of W doping on the structural, thermochromic, and thermophysical properties of VO2 were examined. Using X-ray diffraction (XRD), it was found that the addition of W atoms affected the VO2 lattice since the crystal structure of VO2 was changed from monoclinic to tetragonal rutile. Subsequently, this influenced the thermochromic behavior of the prepared VO2. Based on the differential scanning calorimetry (DSC), doping with tungsten resulted in a significant decrease in τc from 66.47°C to as low as 31.64°C. Moreover, W doping affected the thermophysical properties of the samples. Accordingly, an abrupt increase in the thermal conductivities of the doped samples was observed across the transition temperature.

scholarly journals Structural, Thermal and Magnetic Properties of Ga Excess Ni-Mn-Ga

2009 ◽  
Vol 635 ◽  
pp. 43-47 ◽  
Author(s):  
Sanjay Singh ◽  
S. Bhardwaj ◽  
A.K. Panda ◽  
V.K. Ahire ◽  
Amitava Mitra ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Transition Temperature ◽  
Martensitic Transition ◽  
Martensitic Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ga Doping ◽  
Heat Of Transformation

The martensitic transition and the ferro- to paramagnetic transition have been studied in a series of Ga excess Ni-Mn-Ga specimens [Ni2-xMnGa1+x (0.4≤ x≤ 0.9)] by differential scanning calorimetry and magnetization measurements. The martensitic transition exhibits a hysteresis whose width is similar to Ni2MnGa, indicating that the transition is thermoelastic. The latent heat of transformation is comparable with other Ni-Mn-Ga alloys. A substantial increase in the martensitic transition temperature is observed due to Ga doping. Interestingly, the x-ray diffraction pattern of all the compositions studied show a modulated martensitic structure in the martensitic phase.

scholarly journals Extraction of Al-Si master alloy and alumina from coal fly ash

2017 ◽  
Vol 53 (2) ◽  
pp. 155-162 ◽  
Author(s):  
A. Liu ◽  
Z. Shi ◽  
K. Xie ◽  
X. Hu ◽  
B. Gao ◽  
...  
Keyword(s):  
Fly Ash ◽  
Master Alloy ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Raw Material ◽  
Aluminothermic Reduction ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Coal fly ash from coal power plants is a potential raw material for the production of alumina. An objective aluminothermic reduction method for the preparation of Al-Si master alloy and alumina from coal fly ash was investigated. The kinetic analysis using non-isothermal differential scanning calorimetry indicated that the reduction of Al6Si2O13, Fe2O3, and TiO2 by aluminum in coal fly ash occurs at 1618 K, 1681 K, and 1754 K, respectively. Moreover, the influence of reaction temperature on product composition was studied. The phases and morphologies of the products obtained by the aluminothermic reduction of coal fly ash at 1373-1773 K were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy, respectively. The results from X-ray diffraction show that no oxide reduction has taken place at 1373 K and 1473K, the compositions of the product obtained by aluminothermic reduction of fly ash at 1573K- 1673 K are Al2O3, mullite, Al and Si, while the compositions of the product at 1773 K are Al2O3, Al, and Si. In addition, the chemical compositions of Al-Si alloy obtained at 1773 K are 86.81 wt% Al and 13.19 wt% Si.

A time-resolved SAXS study on the crystalline morphology of long-term stored isotactic polypropylene

2004 ◽  
Vol 37 (2) ◽  
pp. 295-299 ◽  
Author(s):  
Jun-Ting Xu ◽  
Yu-Jin Zhang ◽  
Zhi-Qiang Fan
Keyword(s):  
Isotactic Polypropylene ◽  
Crystal Form ◽  
Crystalline Morphology ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Time Resolved ◽  
Crystal Forms ◽  
X Ray ◽  
X Ray Scattering

The crystalline morphology of a long-term stored metallocene isotactic polypropylene (mPP) has been studied with time-resolved small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and compared with that of the freshly crystallized sample. It was found that both α and γ crystal forms occur in the long-term stored mPP, whereas freshly crystallized mPP contains only the α crystal form. Double SAXS peaks were observed for the long-term stored mPP, which can be assigned to the α and γ crystals. Based on the SAXS result, it is inferred that the crystal stacks of the α and γ forms in the long-term stored mPP are arranged according to the block mode.

Structure and Low Melting Property of Vanadate Tellurite Glass

2010 ◽  
Vol 663-665 ◽  
pp. 1229-1233 ◽  
Author(s):  
Shi Yong Luo ◽  
Wen Cai Xu ◽  
Xin Lin Zhang ◽  
Li Xia Huo
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Tellurite Glass ◽  
Melting Process ◽  
Glass Frit ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The glasses (80-x)TeO2·xV2O5·20MO (M=Sn, Bi, Ca, Na and K) had been examined as potential replacements for PbO-based glass frits with low firing temperature. The glasses with TeO2 0-44 mol%, and V2O5 39-82 mol% are not suitable for glass frit since they are easy to crystallize. The glasses with the content of the TeO2 54-74 mol%, and the V2O5 9-29 mol% were investigated by differential scanning calorimetry, X-ray diffraction, infrared spectra and fluidity evaluation experiments. The glasses possess appropriate fluidity and do not crystallize in the re-melting process at 723-753 K. The glass transition temperature of the glasses is at 544-578 K. The structure of the glasses is layer upon layer mainly connected by the structure units of [VO4] and [TeO3]. Other modifier ions locate mainly between the layers. The isolated V=O band from the VO5 bipyramids is not occurred in the vitreous structure of the glasses.

scholarly journals Polymorphic Characterization, Pharmacokinetics, and Anti-Inflammatory Activity of Ginsenoside Compound K Polymorphs

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1983
Author(s):  
Yun-Yan Kuang ◽  
Xuan Gao ◽  
Yi-Jun Niu ◽  
Xun-Long Shi ◽  
Wei Zhou
Keyword(s):  
Significant Inhibition ◽  
Female Group ◽  
Sex Dimorphism ◽  
X Ray Diffraction ◽  
Compound K ◽  
Scanning Calorimetry ◽  
Crystal Forms ◽  
X Ray ◽  
Ginsenoside Compound K ◽  
Scanning Electron

Polymorphism exhibits different physicochemical properties, which can impact the bioavailability and bioactivity of solid drugs. This study focused on identifying the polymorphs of ginsenoside compound K (CK) and studying their different behaviors in pharmacokinetics (PK) and pharmacodynamics (PD). Four CK polymorphs (form I, II, III, and IV) from organic solvents were characterized by scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (PXRD). A feasible LC-MS/MS method was exploited to determine the PK parameters. Form II displayed the most exposure, followed by form I, III, and IV. Notably, all forms showed sex dimorphism, and the bioavailability in the female group was about two-fold higher than in the male group. The PD properties were investigated in carrageenan-induced acute paw inflammation, and form II at 20 mg/kg showed significant inhibition of edema by 42.7%. This study clarified the polymorphic, PK, and PD characters of four crystal forms of CK, and the data suggested that form II had the best efficacy for drug development.

Fabrication and study the effect of the laser on the properties of the compound Tl2-xHgxBa2-ySryCa2Cu3O10+δ superconductor

2018 ◽  
pp. 168
Author(s):  
A. Kareem Dahash Ali ◽  
Nihad Ali Shafeek
Keyword(s):  
Transition Temperature ◽  
Solid State ◽  
Hydrostatic Pressure ◽  
Electrical Properties ◽  
Co2 Laser ◽  
Temperature Shift ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Electrical Properties

This study included the fabrication of    compound (Tl2-xHgxBa2-ySryCa2Cu3O10+δ) in a manner solid state and under hydrostatic pressure ( 8 ton/cm2) and temperature annealing(850°C), and determine the effect of the laser on the structural and electrical properties elements in the compound, and various concentrations of x where (x= 0.1,0.2,0.3 ). Observed by testing the XRD The best ratio of compensation for x is 0.2 as the value of a = b = 5.3899 (A °), c = 36.21 (A °) show that the installation of four-wheel-based type and that the best temperature shift is TC= 142 K  .When you shine a CO2 laser on the models in order to recognize the effect of the laser on these models showed the study of X-ray diffraction of these samples when preparing models with different concentrations of the values ​​of x, the best ratio of compensation is 0.2 which showed an increase in the values ​​of the dimensions of the unit cell a=b = 5.3929 (A °), c = 36.238 (A°). And the best transition temperature after shedding laser is TC=144 K. 

Sign in / Sign up

Export Citation Format

Share Document