61 research outputs found
Радикальная сополимеризация стирола и α-ангеликалактона: синтез и свойства полученных сополимеров
Biodegradation ability of synthetic polymer materials is an urgent problem of modern ecology
situation. A known new biodegradable polymer is polyangelicalactone (PAL). In this paper, styrene-α-
angelicalactone copolymers were obtained by radical polymerization. The resulting copolymers have
physical and mechanical properties similar to those of polystyrene and its graft-copolymers
with PAL.
Both they were mechanically destroyed when incubated in gray forest soil over 28 weeks. The obtained
results show that the modification of polystyrene with the impurities of α-angelicalactone
does not
worsen the mechanical properties of the copolymers but instead gives them biodegradation abilitiesВ настоящей работе получены сополимеры стирола и α-ангеликалактона
методом
радикальной полимеризации. Полученные сополимеры имеют физико-механические
свойства,
аналогичные свойствам
полистирола и его привитых сополимеров с полиангеликалактоном. Оба
полимера механически разрушаются при инкубации в серой лесной почве в течение 28 недель.
Полученные результаты показывают, что модификация полистирола примесями α-ангеликалактона
не ухудшает механические свойства
сополимеров и придает им способность к биоразложени
Determination of hydroxyl groups in biorefinery resources via quantitative 31P NMR spectroscopy
The analysis of chemical structural characteristics of biorefinery product streams (such as lignin and tannin) has advanced substantially over the past decade, with traditional wet-chemical techniques being replaced or supplemented by NMR methodologies. Quantitative 31P NMR spectroscopy is a promising technique for the analysis of hydroxyl groups because of its unique characterization capability and broad potential applicability across the biorefinery research community. This protocol describes procedures for (i) the preparation/solubilization of lignin and tannin, (ii) the phosphitylation of their hydroxyl groups, (iii) NMR acquisition details, and (iv) the ensuing data analyses and means to precisely calculate the content of the different types of hydroxyl groups. Compared with traditional wet-chemical techniques, the technique of quantitative 31P NMR spectroscopy offers unique advantages in measuring hydroxyl groups in a single spectrum with high signal resolution. The method provides complete quantitative information about the hydroxyl groups with small amounts of sample (~30 mg) within a relatively short experimental time (~30-120 min)
Bright Side of Lignin Depolymerization:Toward New Platform Chemicals
Lignin,
a major component of lignocellulose, is the largest source
of aromatic building blocks on the planet and harbors great potential
to serve as starting material for the production of biobased products.
Despite the initial challenges associated with the robust and irregular
structure of lignin, the valorization of this intriguing aromatic
biopolymer has come a long way: recently, many creative strategies
emerged that deliver defined products via catalytic or biocatalytic
depolymerization in good yields. The purpose of this review is to
provide insight into these novel approaches and the potential application
of such emerging new structures for the synthesis of biobased polymers
or pharmacologically active molecules. Existing strategies for functionalization
or defunctionalization of lignin-based compounds are also summarized.
Following the whole value chain from raw lignocellulose through depolymerization
to application whenever possible, specific lignin-based compounds
emerge that could be in the future considered as potential lignin-derived
platform chemicals
A Novel Vanadium Catalyst for Oxidation of Hydrogen Chloride with Dioxygen
A novel catalytic system for oxidation of hydrogen chloride, V2O5-LiCl-KCl, has been studied. This
catalyst shows activity in a range of relatively low temperatures, 250 - 350 °C. Chlorine yield attains
200 - 780 g per kg of catalyst per hour at 350 °C, which greatly exceeds the characteristics of known
vanadium, copper and chromia catalysts
A New Vanadium Catalyst for Chlorine Production by Hydrogen Chloride Oxidation
Показано, что промышленный ванадиевый катализатор окисления диоксида серы ИК-1-6 активен в процессе окисления хлористого водорода в молекулярный хлор (производительность до 180 грамм хлора на килограмм катализатора в час при 400 оС). Показано, что катализатор стабилен в течение 6 часов и предложены пути создания стабильно работающей каталитической установки для производства хлора.Industrial vanadia catalyst for SO2 oxidation, IK-1-6, was shown to be efficient in a process of hydrogen chloride oxidation into molecular chlorine. The productivity of the catalyst attains values of 180 grams of chlorine per kilogram of catalyst per hour at 400 oC. The catalyst was shown to be stable for 6 hours. A way to create a stable-operating catalytic system for chlorine production is suggested
Study of Plant Growth Promoting Activity and Chemical Composition of Pine Bark after Various Storage Periods
Composition and content of terpene compounds in pine bark (Pinus sylvestris) after various storage
periods were studied by GLC-MS. Resin acids were found to be the main diterpenoic compounds in
the bark. Content of dehydroabietic acid in initial bark is 0.6 g/kg and it decreases three-fold after one
year of storage. High activity of pine bark after various storage periods towards risogenesis of wheat
(Triticum aestivum) was discovered. Strong correlation (r = 0.89) between growth promoting activity
of pine bark and content of dehydroabietic acid in it was found
Extraction of Vanillin by Aliphatic Alcohols
Исследованы экстракционные равновесия в системе вода - высший алифатический спирт -
ванилин в зависимости от рН среды, ионной силы и начальной концентрации ванилина в
растворах. Определены коэффициенты распределения ванилина. Показано, что значения
коэффициентов распределения ванилина (рН 9-10) между водой и спиртами изменяются в
пределах 1-10, что позволяет применять их для многоступенчатой противоточной экстракции
в промышленности. При значениях рН 11-14 коэффициенты распределения составляют 0.1-0.2,
что позволяет реэкстрагировать ванилин водно-щелочным раствором.Vanillin extraction from alkaline solutions by means of higher-homologues alcohols was studied.
Effects of pH as well as vanillin concentration and ion strength on vanillin-aqua-alcohol equilibrium
were studied. The data on distribution ratios (D) of vanillin were obtained. The values of distribution
ratios at technological pH (about 9-10) are shown to be equal to 1 - 10, that approaches for multistage
reverse-flow extraction. If pH values is 11-14 then the distribution ratios values less then 0.2, that
makes easy the vanillin stripping process to aqueous phase
A Novel Vanadium Catalyst for Oxidation of Hydrogen Chloride with Dioxygen
A novel catalytic system for oxidation of hydrogen chloride, V2O5-LiCl-KCl, has been studied. This
catalyst shows activity in a range of relatively low temperatures, 250 - 350 °C. Chlorine yield attains
200 - 780 g per kg of catalyst per hour at 350 °C, which greatly exceeds the characteristics of known
vanadium, copper and chromia catalysts
A New Vanadium Catalyst for Chlorine Production by Hydrogen Chloride Oxidation
Показано, что промышленный ванадиевый катализатор окисления диоксида серы ИК-1-6 активен в процессе окисления хлористого водорода в молекулярный хлор (производительность до 180 грамм хлора на килограмм катализатора в час при 400 оС). Показано, что катализатор стабилен в течение 6 часов и предложены пути создания стабильно работающей каталитической установки для производства хлора.Industrial vanadia catalyst for SO2 oxidation, IK-1-6, was shown to be efficient in a process of hydrogen chloride oxidation into molecular chlorine. The productivity of the catalyst attains values of 180 grams of chlorine per kilogram of catalyst per hour at 400 oC. The catalyst was shown to be stable for 6 hours. A way to create a stable-operating catalytic system for chlorine production is suggested
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