percent crystallinity
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2019 ◽  
Vol 948 ◽  
pp. 9-13
Author(s):  
Anggun Lestari ◽  
Simparmin B. Ginting ◽  
Hens Saputra

ZSM-5 has been successfully synthesized by seeding method using coal bottom ash and rice husk as the sources of silica and alumina.Synthesis ZSM-5 were performed by the hydrothermal method in autoclave autogenous at 180 °C for 36 h with molar ratio 10Na : 50SiO : 2Al2O3 : 500H2O with the addition of ZSM-5 commercial as seed. In this experiments, investigated variations seed amounts of 5, 10, 15, and 20% of weight silica. The product was characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), and Brunauer-Emmet-Teller (BET). Resulted showed that ZSM-5 succeed formed in all variation of seed contain. At variation seed amount 5%, crystallinity obtained still low in which content of quartz phase still be high. Percent crystallinity highest obtained at the variation of seed amount 20% with the result percent crystallinity relative 106%. The experimental results revealed that phase transformation has occurred, in which an amorphous phase of coal bottom ash and rice husk has been transformed to the ZSM-5 crystal with addition seed as substitution organic template.


2018 ◽  
Vol 15 (4) ◽  
pp. 566-571 ◽  
Author(s):  
Araceli Martinez ◽  
Mikhail A. Tlenkopatchev ◽  
Selena Gutierrez

Background: Ring opening metathesis polymerization of lactones using alkylidene catalysts is an alternative to obtain unsaturated linear polyesters with remarkable thermal and mechanical properties. Also, these polyesters have properties of biodegradability which opens up a wide range of applications as environmentally friendly thermoplastics and biomaterials. Objective: This research aims to present one route to obtain an unsaturated linear polyester poly(ω-6- hexadecenlactone) via ring opening-metathesis polymerization of ω-6-hexadecenlactone using the rutheniumalkylidene [Ru(Cl)2(=CHPh)(PCy3)2] (I), [Ru(Cl2)(=CHPh)(1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)( PCy3)] (II) and [Ru(Cl2)(=CH(o-isopropoxyphenylmethylene))(1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)] (III) and the ruthenium-vinylidene [RuCl2(=C=CH(p-C6H4CF3))(PCy3)2] (IV) catalysts. Conclusion: The high number-average molecular weights of the poly(ω-6-hexadecenlactone) between Mn = 114,800-155,400 g/mol and yields ranging from 96 to 98 % can be achieved by II and III catalysts. The catalysts II and III with the N-heterocyclic carbene ligand showed superior activity and stability upon catalysts I and IV bearing PCy3 ligands. The hydrogenation of poly(ω-6-hexadecenlactone) using Wilkinson catalyst [RhCl(PPh3)3] was studied. The percent crystallinity of the unsaturated poly(ω-6-hexadecenlactone) was 31% with a melting temperature 47.60ºC. Stress-strain measurements of several poly(ω-6-hexadecenlactone) were determined.


2016 ◽  
Vol 88 (9) ◽  
pp. 4644-4650 ◽  
Author(s):  
Ashok Zachariah Samuel ◽  
Mengbo Zhou ◽  
Masahiro Ando ◽  
Robert Mueller ◽  
Tim Liebert ◽  
...  

2014 ◽  
Vol 29 (2) ◽  
pp. 123-126 ◽  
Author(s):  
Sudheer Bandla ◽  
Masoud Allahkarami ◽  
Jay C. Hanan

The dependence of polymer properties on their processing history can be used advantageously. Polyethylene terephthalate (PET), a semi-crystalline polymer, exhibits a microstructure reliant on process and thermal history. PET undergoes strain-induced crystallization, making it sensitive to mechanical stretching. As the level of crystallinity in PET governs its mechanical behavior, it is necessary to quantify the effect of crystallinity and molecular orientation for efficient use. The present research is focused on an approach that will aid in correlating the stretch ratio of PET films to the percent crystallinity and mechanical properties. PET films with different local stretch ratios were obtained through bi-axially stretching injection-molded cylinders of increasing thickness and weight. Percent crystallinity of the PET films with different stretch ratios was measured using X-ray diffraction. Film samples were marked with respect to the stretch directions for measuring their longitudinal (primary stretch direction) and transverse mechanical properties. Local molecular orientation in the form of pole figures was mapped using the (100) plane corresponding to the PET lattice. This will help in linking the physical sample directions and processing to the molecular orientation. Associating the mechanical properties with molecular alignment helps in designing production processes that realize the material's structural potential.


2013 ◽  
Vol 634-638 ◽  
pp. 1454-1459
Author(s):  
Yi Ming Zhou ◽  
Xiao Li Zhou ◽  
Ying Xiao ◽  
Ning Liu ◽  
Yue Chen

The changes in physicochemical properties of tartary buckwheat starch during germination process were studied in the present study. After germination, there was a moderate increase in loss of starch (4.4~5.9%). The outcomes from scanning electron microscope indicated that the process of germination moderately increased the multi-pore around the granules of starch. The X-ray diffraction pattern of raw starch showed an A-pattern. Germination process did not distinctly affect X-ray diffraction patterns, but percent crystallinity of starch were increased with the increase of germination. Germination process raised the solubility of buckwheat starch but did not distinctly affect swelling capacity. The paste clarity and freeze–thaw stability of starch were improved after 24-h germination, but the germinated starch for 36 h exhibited no improvements in these properties compared with the raw starch. Therefore, moderate germination improved some physicochemical properties of tartary buckwheat starch.


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