scholarly journals Highly soluble cellulose nitrates from unconventional feedstocks

2018 ◽  
Vol 243 ◽  
pp. 00005
Author(s):  
Yulia Gismatulina ◽  
Anna Korchagina ◽  
Vera Budaeva ◽  
Gennady Sakovich
Keyword(s):  
Chemical Shifts ◽  
Temperature Treatment ◽  
Exothermic Peak ◽  
High Temperature Treatment ◽  
Absorption Bands ◽  
Oat Hulls ◽  
Mixed Acid ◽  
Nitration Product ◽  
Cellulose Nitrates ◽  
C Nmr

Celluloses isolated by the nitric-acid process from domestic unconventional feedstocks such as Miscanthus, oat hulls, and intermediate flax straw were used herein to produce cellulose nitrates (CNs) with a high solubility. For the synthesis of CNs, a commercial technique was employed that involves nitration of cellulose with mixed acid containing 14 wt.% water followed by high-temperature treatment of the nitration product in acidic, alkaline, and neutral environments. The obtained CNs are similar in physicochemical attributes: 12.04–12.26% mass fraction of nitrogen, 10–14 mPa·s viscosity, and 98% solubility in alcohol– ester mixture. FTIR spectra of CNs had absorption bands (2559–2557, 1646–1631, 1277–1271, 825–812, 747–744, 683–680 cm-1) typical of nitro group vibrations. 13C NMR spectra showed chemical shifts representative of 6-mononitrocellulose, 2,6-dinitrocellulose, 3,6-dinitrocellulose, and 2,3,6-trinitrocellulose. DSC revealed that the resultant CNs were highly chemically pure with an exothermic peak at 209–212°С. The CNs obtained from the said unconventional feedstocks were compared with a commercial, highviscosity, lacquer-grade Colloxylin derived from cotton cellulose, as well as with other commercial Colloxylins, to show that the experimental CNs meet the requirements for comercial grades. Thus, the CNs obtained from the unconventional feedstocks are promising candidates as the component of composite explosives.

scholarly journals Oat-hull cellulose nitrates for explosive compositions

2019 ◽  
Vol 487 (4) ◽  
pp. 391-395
Author(s):  
G. V. Sakovich ◽  
V. V. Budaeva ◽  
А. А. Korchagina ◽  
Yu. А. Gismatulina ◽  
N. V. Kozyrev ◽  
...  
Keyword(s):  
High Viscosity ◽  
Scanning Calorimetry ◽  
High Chemical ◽  
Oat Hulls ◽  
Mixed Acid ◽  
Chemical Structures ◽  
Chemical Purity ◽  
Cellulose Nitrates ◽  
Composite Explosives ◽  
High Chemical Stability

Cellulose nitrates similar in basic properties to high-viscosity lacquer-grade Colloxyline were synthesized by esterification of pulp with mixed acid. The pulp was isolated from the easily renewable domestic feedstock - oat hulls - the agro-industrial waste. The cellulose nitrate test samples were comparatively evaluated. Infrared and 13C NMR spectroscopies confirmed the chemical structures were identical. It was established by differentiated scanning calorimetry and ampule chromatography that the samples had a high chemical purity. The cellulose nitrates were found to have satisfactory impact and friction sensitivities of 50 mm and 1200 kgf/cm2 and exhibit a good chemical compatibility and a high chemical stability when blended with plasticizers. The findings suggest that it is advisable to use oat-hull cellulose nitrates as the component of composite explosives. 

scholarly journals PROSPECTS OF CELLULOSE NITRATES FROM UNCONVENTIONAL FEEDSTOCKS FOR USE IN COMPOSITE EX-PLOSIVES

2019 ◽  
pp. 259-268 ◽  
Author(s):  
Геннадий (Gennadiy) Викторович (Viktorovich) Сакович (Sakovich) ◽  
Вера (Vera) Владимировна (Vladimirovna) Будаева (Budaeva) ◽  
Анна (Anna) Александровна (Aleksandrovna) Корчагина (Korchagina) ◽  
Юлия (Yuliya) Александровна (Aleksandrovna) Гисматулина (Gismatulina)
Keyword(s):  
Practical Importance ◽  
Research Problem ◽  
Degree Of Polymerization ◽  
Short Fibers ◽  
Wood Cellulose ◽  
Oat Hulls ◽  
Cellulosic Fibers ◽  
Mixed Acid ◽  
Industrial Grade ◽  
Cellulose Nitrates

Research on the synthesis of in-demand industrial-grade cellulose nitrates from unconventional feedstocks such as Miscanthus, oat hulls, intermediate flax straw is of the most immediate interest due to a lack of national cotton and to encountered problems with wood cellulose. The celluloses derived herein from the said unconventional feedstocks are inhomogeneous in nature, are composed mostly of short fibers, and have non-cellulosic constituents as opposed to elite cotton – these all pose certain difficulties in developing such a nitrocellulose production technology. Besides, it is worth noting that cellulosic fibers of the said feedstocks are peculiar in nature on their own. The findings obtained herein suggest that the research problem can successfully be solved. The pulp samples obtained in this study from the unconventional biomasses by the nitric-acid process have 85−95% α-cellulose and 580−1420 degree of polymerization. These specimens similar in properties to industrial Colloxylin were obtained under optimal synthetic conditions for highly soluble cellulose nitrates by using commercial mixed acid: 11.97–12.29% N, 8–15 mPa∙s, and 98% solubility in alcohol–ester mixture. The morphological features of the resultant cellulose nitrates were characterized by scanning electron microscopy. Infrared spectroscopy revealed the intrinsic frequencies (2560–2550, 1670–1660, 1650–1620, 1280–1270, 830–810, 750–740, 680–670 cm-1) that identify the resultant products as cellulose nitroesters. The practical importance of this research is that the nitrocelluloses obtained from the unconventional non-woody feedstocks can be used as the promising component in the manufacture of explosive formulations.

Effect of high‐temperature treatment on optical‐absorption bands in amorphous SiO2

1991 ◽  
Vol 70 (5) ◽  
pp. 2788-2790 ◽  
Author(s):  
Nobuyuki Dohguchi ◽  
Shuji Munekuni ◽  
Hiroyuki Nishikawa ◽  
Yoshimichi Ohki ◽  
Kaya Nagasawa
Keyword(s):  
High Temperature ◽  
Optical Absorption ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Absorption Bands ◽  
Amorphous Sio2

17O and 13C NMR spectra of some geminal diacetates

1988 ◽  
Vol 53 (3) ◽  
pp. 588-592 ◽  
Author(s):  
Antonín Lyčka ◽  
Josef Jirman ◽  
Jaroslav Holeček
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
The Other ◽  
13C Nmr Spectra ◽  
Other Hand ◽  
Carboxylic Esters ◽  
C Nmr ◽  
Oxygen Atoms

The 17O and 13C NMR spectra of eight geminal diacetates RCH(O(CO)CH3)2 derived from simple aldehydes have been measured. In contrast to the dicarboxylates R1R2E(O(CO)R3)2, where E = Si, Ge, or Sn, whose 17O NMR spectra only contain a single signal, and, on the other hand, in accordance with organic carboxylic esters, the 17O NMR spectra of the compound group studied always exhibit two well-resolved signals with the chemical shifts δ(17O) in the regions of 183-219 ppm and 369-381 ppm for the oxygen atoms in the groups C-O and C=O, respectively.

Carbon-13 and nitrogen-14 NMR spectra of 1-(substituted phenyl)pyridinium salts

1980 ◽  
Vol 45 (10) ◽  
pp. 2766-2771 ◽  
Author(s):  
Antonín Lyčka
Keyword(s):  
Heavy Water ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Pyridinium Salts ◽  
Nmr Signals ◽  
C Nmr

The 13C and 14N NMR spectra of 1M solutions of 1-(substituted phenyl)pyridinium salts (4-CH3, 4-OCH3, H, 4-Cl, 4-Br, 4-I, 3-NO2, 4-NO2, 2,4-(NO2)2 (the 13C NMR only)) have been measured in heavy water at 30 °C. The 13C and 14N chemical shifts, the 1J(CH) coupling constants, some 3J(CH) coupling constants, and values of half-widths Δ 1/2 of the 14N NMR signals are given. The 13C chemical shifts of C(4) correlate with the σ0 constants (δC(4) = (1.79 ± 0.097) σ0 + (147.67 ± 0.041)), whereas no correlation of the nitrogen chemical shifts with the σ constants has been found. The half-widths Δ 1/2 correlate with the σ0 constants (Δ 1/2 = (76.2 ± 4.9) σ0 + (106.4 ± 2.2)) except for 1-phenylpyridinium chloride.

Proximity and conformation effects in 29Si and 13C NMR spectra of di-ortho substituted trimethylsiloxybenzenes

1990 ◽  
Vol 55 (8) ◽  
pp. 2027-2032 ◽  
Author(s):  
Jan Schraml ◽  
Robert Brežný ◽  
Jan Čermák
Keyword(s):  
Benzene Ring ◽  
13C Nmr ◽  
Proximity Effect ◽  
Nmr Spectra ◽  
Methoxy Group ◽  
Chemical Shifts ◽  
Proximity Effects ◽  
13C Nmr Spectra ◽  
Methoxy Groups ◽  
C Nmr

29Si and 13C NMR spectra of five 4-substituted 2,6-dimethoxytrimethylsiloxybenzenes were studied with the aim to elucidate the nature of the deshielding proximity effects observed in the spectra of ortho substituted trimethylsiloxybenzenes. The sensitivity of 29Si chemical shifts to para substitution is in the studied compounds essentially the same as in mono ortho methoxytrimethylsiloxybenzenes. The deshielding proximity effect of the ìsecondî methoxy group is somewhat smaller than that of the ìfirstî group. The present results indicate that the two methoxy groups assume coplanar conformations with the benzene ring and are turned away from the trimethylsiloxy group which is not in the benzene plane. It is argued that in mono ortho methoxytrimethylsiloxybenzenes the two substituent groups adopt the same conformations as in the compounds studied here.

scholarly journals Setosphlides A–D, New Isocoumarin Derivatives from the Entomogenous Fungus Setosphaeria rostrate LGWB-10

2021 ◽  
Author(s):  
Wenbin Gao ◽  
Xiaoxia Wang ◽  
Fengli Chen ◽  
Chunqing Li ◽  
Fei Cao ◽  
...  
Keyword(s):  
Harmonia Axyridis ◽  
Chemical Shifts ◽  
Human Tumor ◽  
Tumor Cell Lines ◽  
Human Tumor Cell ◽  
Human Tumor Cell Lines ◽  
Entomogenous Fungus ◽  
Planar Structures ◽  
Mcf 7 ◽  
C Nmr

Abstract Investigation of the entomogenous fungus Setosphaeria rostrate LGWB-10 from Harmonia axyridis led to the isolation of four new isocoumarin derivatives, setosphlides A–D (1–4), and four known analogues (5–8). Their planar structures and the relative configurations were elucidated by comprehensive spectroscopic methods. The absolute configurations of isocoumarin nucleus for 1–4 were elucidated by their ECD spectra. The C-10 relative configurations for the pair of C-10 epimers (1 and 2) were established by comparing the magnitude of the computed 13C NMR chemical shifts (Δδcalcd.) with the experimental 13C NMR values (Δδexp.) for the epimers. All of the isolated compounds (1–8) were evaluated for their cytotoxicities against four human tumor cell lines MCF-7, MGC-803, HeLa, and Huh-7. Graphic Abstract

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