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The concept and flow model of a structured dispersed system obtained on the basis of sulfate lignin modified by Sol-gel method in the presence of aluminum-containing components in the form of nepheline concentrate are considered. The systems are mainly systems of non-Newtonian behavior, characterized by phenomena of destruction and formation of new structures in the shear flow, and the nature of the flow depends on the characteristics of interaction between system components, which are defined as their concentrations, and process conditions of the synthesis, at which the change of the adhesion forces between particles and at the moment cannot be generalized and described existing well-known equations of flow.As a result of the study, it was found that an increase in the concentration of sulfate lignin under various synthesis conditions, but with a constant amount of mineral component, leads to the formation of a new modified product, while there is a tendency to increase the parameters of kinematic viscosity and shear stress at the corresponding pH values of synthesis. Under conditions of excessive lignin concentrations of more than 400 mg/dm3, when self-organizing in the matrix of a new form, lignin dominance leads to a decrease in the strength characteristics of the polymer for all its forms obtained at different pH values. It is established that the kinematic viscosity and shear stress of water dispersions in this system depend on both the pH value of their synthesis and the concentration of the initial lignin, which determines the mechanisms of self-organization of the new modified structure., Рассмотрены концепция и модель течения структурированной дисперсной системы, полученной на основе сульфатного лигнина, модифицированного золь-гель способом в присутствии алюмосодержащих компонентов в виде нефелинового концентрата. Полученные системы преимущественно относятся к системам неньютоновского поведения, которые характеризуются явлениями разрушения и образования новых структур в процессе сдвигового течения, причем характер течения зависит от особенностей взаимодействия компонентов системы. Данные особенности определяются как их концентрацией, так и условиями процесса синтеза, при котором происходит изменение сил сцепления между частицами, и в данный момент не могут быть обобщены и описаны существующими известными уравнениями течения. В результате исследования было установлено, что увеличение концентрации сульфатного лигнина при различных условиях синтеза, но при постоянном количестве минеральной составлявшей, приводит к формированию нового модифицированного продукта, при этом наблюдается тенденция увеличения параметров кинематической вязкости и напряжения сдвига при соответствующих значениях рН синтеза. В условиях избыточных концентраций лигнина более 400 мг/дм3 при самоорганизации в матрице новой формы доминирование лигнина приводит к снижению прочностных характеристик полимера для всех его форм, полученных при различных значениях рН. Установлено, что кинематическая вязкость и напряжение сдвига водных дисперсий данной системы зависит как от значения рН их синтеза, так и от концентрации исходного лигнина, который определяет механизмы самоорганизации новой модифицированной структуры.

Slow-release fertilizers represent a possible large-scale application for plant polymers. Here we show a facile way to stabilize urea in fertilizer systems by lignin. Chelation of kraft black liquor with calcium acetate at pH 13 precipitated lignin as a calcium complex (Ca-lignin), which offered beneficial effects if compared to those from lignin obtained by precipitation at low pH (Acid-lignin). The reduced affinity of water to Ca-lignin was exploited in the formulation of slow release fertilizers comprising wheat straw sections impregnated with Ca-lignin in molten urea. Compared to the case of Acid-lignin, immersion in water was slowed down more extensively by Ca-lignin. After 24 h incubation at low moisture conditions, the highest proportion of urea retained in the Ca-lignin/straw fertilizer system was 58%. The water resistance of Ca-lignin was explained by a lower aqueous solubility that differed from the typical pH-dependent solubility of Acid-lignin. Electron microscopy, infrared spectroscopy, and accessible surface areas suggested that Ca-lignin consisted of less densely packed molecules organized as calcium-chelated chains. Overall, the controlled water-solubility of lignin precipitated by metal cations is greatly beneficial in fertilizer systems and can open new opportunities in material development (permeable films and others).

Pašlaik Baltijas valstīs darbojas tikai viena celulozes rūpnīca Horizon Pulp & Paper Ltd Kehrā, Igaunijā, kas ražo plaša klāsta papīra izstrādājumus iesaiņojumu industrijai. Tas ir arī vienīgais šā brīža lignīna avots Baltijas valstīs. Tomēr līdz šim Kehras celulozes rūpnīcā iegūtā melnā atsārma sastāvā ietilpstošais lignīns nav izpētīts. Mūsu darba mērķis bija no Kehras rūpnieciskā melnā atsārma izdalīt sulfātlignīnu, raksturot tā ķīmisko sastāvu un pārbaudīt virsmas aktīvās īpašības. Pamatojoties uz darbā iegūtajiem rezultātiem tika konstatēts, ka izdalītais sulfātlignīns pēc saviem rādītājiem būtiski neatšķiras no pārējiem rūpnieciskajiem un komerciālajiem sulfātlignīniem. Noskaidrots, ka ar sulfātlignīna koncentrācijas palielināšanu un šķīduma pH pazemināšanu, sulfātlignīna virsmas aktivitāte šķīdums-gaiss fāzu robežā un eļļa-ūdens emulsijās palielinās. Pie tā lielām koncentrācijām labāka emulsiju stabilitāte novērojama skābā vidē, bet pie mazām – sārmainā vidē, kas izskaidrojams ar dažādiem emulsiju stabilizācijas mehānismiem. Noteikts, ka 0,1 M NaCl klātbūtne šķīdumā labvēlīgi iedarbojas uz sulfātlignīna virsmas aktivitāti, kas saistīts ar sulfātlignīna molekulu hidrofobitātes paaugstināšanos jonu spēka palielināšanās rezultātā.

The study of lignin with the aim of correlating data, which may lead to a greeter utilization of this wood waste product, has been the subject of investigations since 1838. Previous investigations by Othmer, Harris, Sherrard and others have indicated that chlorinated lignin had potential value as a plastic. The purpose of this investigation was to study the chlorination reaction of lignin obtained from the black liquors of the sulfate process of paper manufacture. Results of preliminary experimental work indicated that the optimum method of chlorinating lignin was by suspending or dissolving the lignin in methyl alcohol. The sulfate lignin was chlorinated in two liter wolff flask which was equipped with a motor driven stirrer, and the chlorine flow was measured by a calibrated U-tube differential gage. The flask was charged with the alcohol-lignin mixture and chlorinated from one to seven hours. The rates of chlorine flow for the tests were 0.472, 0.85 and 1.084 gm. Cl₂/min at temperatures of 25 and 65ºC. The reactant gases were passed through a condenser to return the vaporized alcohol to the reaction flask and then into a 3 normal sodium hydroxide solution to react the excess chlorine gas. Samples of the reaction gas, which were analyzed for chlorine, were collected in a 1.5 normal sodium hydroxide solution at 10 minutes intervals. With this information the progress of the reaction could be plotted and the rate of chlorination measured. The chlorination of a suspension of lignin in methyl alcohol in a ratio of l to 20 was possible at 25°C. The critical temperature above which the lignin would not stay in solution was 43°C. The reaction was exothermic and produced an orange colored product containing 25 per cent chlorine. Increasing the rate of chlorine flow from 0.85 to 1.084gm. Cl₂/min. increased the chlorine consumption from 0.74 to 0.833 gm Cl₂/min. The chlorination of lignin dissolved in methyl alcohol produced two chlorinated products. One was precipitated as an orange red powder from solution during the chlorination reaction, and had a chlorine percentage as high as 29 per cent. The other lignin remained dissolved in the alcohol solution. When precipitated from solution by ice water this chloro-lignin was a light yellow powder with a chlorine percentage as high as 28.0 per cent. Increasing the rate or chlorine flow trom 0.472 to 1.084 gm Cl₂/min. during tests at 25°C resulted in increasing the rate of chlorination from 0.454 to 0.935gm Cl₂/min. Adding ferric chloride, as a catalyst, increased the chlorine consumption from 0.768 to 0.967 gm Cl₂/min. Raising the reaction temperature from 25 to 65°C decreased the chlorine consumption trom 0.935 to 0.768 gm. Cl₂/min. The chlorinated product showed definite bonding value when mixed with sawdust and pressed at a temperature or 112°C and pressures from 1000 to 5000 lb/in². The percentage lignin in the samples was varied from 5 to 60 per cent. The lignin-sawdust samples were light yellow in color and firmly bonded and water resistant. Master of Science