Rubber Extraction Research Articles

Insight into Mechanical Extraction Mechanisms of Natural Rubber Extraction from Taraxacum kok-saghyz

Insight into Mechanical Extraction Mechanisms of Natural Rubber Extraction from <i>Taraxacum kok-saghyz</i>

HISTÓRIA ORAL, FIGURAÇÃO E INTERPRETAÇÃO DO SERINGUEIRO: UMA ANÁLISE DA REPRESENTÇÃO SIMBÓLICA PRESENTE NA PRAÇA DOS SERINGUEIROS, EM PORTO VELHO.

The present study aims to present an analytical sketch about the interpretative and polysemic possibility of the figure of the rubber tapper. In this sense, the general objective is to analyze how the representation of the rubber tapper is transformed into symbols and historical meanings in a square in Porto Velho. The specific objectives are guided by presenting the implicit discourses of the symbolic representation constant in the rubber tappers’ square; and describe how the statue of the rubber tapper present in the square translates the history of the rubber plantation as a spatial and temporal mark of discourse and identity; The theoretical foundation will be subsidized, mainly, by Joutard (2000) and Caldas (1997), regarding Oral History. Bakhtin (2003) about text and discourse, and Nora (1993), about symbols and Memory of places. In the area of methodology, the research was developed via bibliographical research, whose nature of the texts and literature it is possible to locate the premises that meet the scope and object of the study. As a result, it can be inferred that there are a variety of possibilities for interpreting the rubber tapper square, with regard to the representative symbols marked by the rubber tapper statue. Thus, it was concluded that what has already been written about the story told via oral history of the rubber tappers still remain as a symbol of social resistance and identity of the historical character that was created throughout the period of rubber extraction in the Amazon.

Natural rubber – Increasing diversity of an irreplaceable renewable resource

This paper discusses the importance of introducing domestic natural rubber production and presents the rediscovery of a rubber-producing species, Scorzonera tau-saghyz or “mountain gum”, originally discovered in 1929 on the Karatau mountains in Kazakhstan. This plant could potentially also be cultivated in the U.S. In this exploratory work, roots (2–5 years old) were harvested on June 16, 2021 from wild strands in the Karatau mountains, Kumantas ridge, and Saraba, Kazakhstan, and processed at the Ohio State University. The rubber extraction method was based on an indigenous method in Kazakhstan to make natural chewing gum. Water extraction followed by purification yielded 16.2 wt% rubber from the dry roots, in comparison with 4–8 wt% from most rubber dandelion (Taraxacum kok-saghyz) plants, also a potential domestic rubber producing plant. High-resolution size exclusion chromatography was used to analyze rubber samples. The molecular weights and gel and oligomer contents were very similar to the rubber from Hevea brasiliensis, the current commercial source of natural rubber. More detailed investigations of this very interesting rubber-producing plant are in progress.

Unraveling the Olmec rubber balls from El Manatí, Mexico: a technological and compositional analysis

This work presents an analysis towards a description of the manufacturing technique of the Olmec rubber balls found at the offerings at El Manatí. The results present this procedure from the extraction of the Mesoamerican rubber from the Castilla elastica tree, discussing its composition and origin of the rubber balls analyzed towards the production of strips that are rolled to make the ball round form. This characterization was achieved through a series of imaging techniques (radiography imaging, UV-induced fluorescence imaging, and optical microscopy) and portable non-destructive and non-invasive analyses (XRF and FTIR) performed on the collection of archaeological rubber balls and compared with contemporary made rubber balls in the region near El Manatí. The methodology was complemented with laboratory chemical analytical techniques (13C NMR-MAS, FTIR, CEA, and GC-MS) applied to selected Olmec rubber microsamples. The new physical and chemical data obtained was also interpreted considering conservation science, to help understand the alterations and transformation processes that the balls have undergone since their recovery in the 1980s.

Rubber genocide in Joyce and Beckett: from Roger Casement’s Congo to Vél d’Hiv and Auschwitz

This essay argues that the political imaginations of both James Joyce and Samuel Beckett were shaped by their familiarity with Roger Casement’s official reports on the catastrophic atrocities that accompanied rubber extraction in the Congo Free State (1904) and Putumayo Amazon (1912). Joyce recognized the depopulation in the Congo as of a structural pattern with Ireland’s long history under British imperialism. But in Dubliners, Joyce clothes characters in consumer rubber to ask whether pursuing much-needed Irish autonomy through economic liberalism also risks backsliding into structural racism. Beckett extends the ethics of Joyce’s racial critique to Le dépeupleur (The Lost Ones), in which novella a “little people” are housed in a rubber cylinder. Here an anthropological narrator describes with French colonial tropes and humanist education why this entire population should die. Beckett’s story borrows elements from Casement and Joyce. But it also takes structure and detail from Vél d’Hiv and Drancy, Parisian holding camps for rounded-up Jews, who were then transported to Auschwitz. (Exterminatory labour from Auschwitz III-Monowitz built a factory to produce synthetic rubber, still in use today.) Beckett reworks Joyce’s caution to confront French society with its complicity in Nazi genocide, an evasion of responsibility that he suggests was prepared in colonial racism and the evisceration of intention in humanist and liberal logics. This essay shows, then, an Irish modernist tradition grappling with an ethical basis for understanding comparative genocide.

Various Retracting techniques for the laparoscopic living donor hepatectomy: double rubber extraction to facilitate liver resection

Various Retracting techniques for the laparoscopic living donor hepatectomy: double rubber extraction to facilitate liver resection

Extractable latex yield from Taraxacum kok-saghyz roots is enhanced by increasing rubber particle buoyancy

Taraxacum kok-saghyz (TK) is a leading alternative rubber-producing plant that produces natural rubber (NR) latex in laticifers within its roots. Unlike the tropical rubber tree, Hevea brasiliensis, TK can be grown in temperate regions, such as the northern United States, as the basis of a domestic rubber production industry. To support such an industry, efficient, scalable rubber extraction techniques are needed. In this study, aqueous extraction was used to recover TK natural rubber latex (TNRL) from four harvests of greenhouse-produced TK roots with a new technique that improves rubber particle buoyancy in root homogenate by chelation. The new method includes harvest, cleaning, and homogenization of freshly harvested roots, followed by centrifugation, vacuum collection of latex, and purification. Treatment of homogenate with ethylenediaminetetraacetic acid (EDTA), a divalent cation chelator, allowed more than twice as much latex to be extracted from fresh homogenate. EDTA-treated rubber particles contained lower concentrations of divalent cations than untreated ones in fresh homogenate and homogenate stored for two weeks. Long term (three months) storage of root homogenate similarly yielded more latex than fresh homogenate and had low divalent cation rubber particle concentrations, indicating that heavy cations had slowly leached from the particles into the aqueous medium during storage. Rubber particle size was larger in this treatment suggestive of rubber particle agglomeration but this was prevented and reversed by EDTA. Removal of divalent cations via chelation increased particle packing density of particles in concentrated latex and appeared to increase the gel content of dried latex samples. Molecular characterization of dried samples of purified TNRL established that the rubber was of the high molecular weight needed for product manufacturing.

Mike Davis: Planetarity and environmentalisms: the invention of new environmental histories from the Ecology of Fear to Victorian Holocausts

Mike Davis transformed the understanding of southern California and dramatically reshaped thinking about the region in his books and many articles for New Left Review. Less well known locally is his significant impact of the approaches to urban environmental history and the large-scale effects of climate events at a global level. Davis can be seen as foundational for global environmental history in his methodology: analyzing the teleconnections and impacts of a particular climate event, (in Victorian Holocausts this was an El Nino) and then parsing out the social effects. The sever El Nino he describes was key in the disenfranchisement of millions in the Colonial worlds and the creation of new indentured and sub-proletariat populations that became the labor force for new forms of plantation agriculture, infrastructure labor, and rubber extraction in tropical forests. Davis’ work provided early historical analysis on the impacts of colonial capitalism in the creation of climate vulnerability. Both his creativity in urban environmental history and its imaginaries, and the foundational research on global climate history are extraordinary contributions.

Preparation of Taraxacum kok-saghyz Rubber and Biofuel Ethanol Simultaneously by the Yeast Fermentation Process.

Taraxacum kok-saghyz(TKS) rubber is considered the most ideal alternative source of natural rubber (NR). Extracting rubber from TKS with high quality, low cost, and low pollution is the basis of commercial development. The TKS roots were subjected to morphological observation and detailed compositional analysis. Scanning electron microscopy (SEM) images confirm that rubber filaments are physically entangled with plant tissues due to differences in molecular polarity. Compared with the traditional solvent TKS rubber extraction process, a new rubber extraction process developed in this study, namely, the microbial extraction (″ME″) process, is less harmful to the environment and lower in cost. The ″ME″ process is divided into three steps: dilute acid pretreatment process, enzyme degradation process, and fermentation process. After each step is completed, the purity of TKS rubber will gradually increase from 84.8% to 93.8 to 95.5%. The TKS rubber finally obtained fully meets the requirements of the traditional rubber industry, especially the tire industry. Besides, the yield of biofuel ethanol, a by-product of cellulose fermentation, reaches 2.05 g/100 g of TKS roots (dry weight), which can effectively reduce the production cost of TKS rubber. In the rubber extraction process, microorganisms have little effect on the quality of TKS rubber. The results show that the molecular weight and chemical structure of TKS rubber is very close to NR, so the ″ME″ process can be used as a new method for large-scale extraction of TKS rubber.

Storage stability performance of composite modified asphalt with scrap non-tire automotive rubber, waste plastic pyrolytic oil and sulfur.

Composite asphalt binder has emerged as a potential solution for improving asphalt functionality at a wide spectrum of temperatures. Storage stability of modified binder remains a main concern to ensure homogeneity during various stages including its storage, pumping, transportation, and construction. The aim of this study was to assess the storage stability of composite asphalt binders fabricated using non-tire waste ethylene-propylene-diene-monomer (EPDM) rubber and waste plastic pyrolytic oil (PPO). The influence of addition of a crosslinking additive (sulfur) was also investigated. Two different approaches were employed in the fabrication of composite rubberized binders: (1) sequential introduction of PPO and rubber granules, and (2) inclusion of rubber granules pre-swelled with PPO at 90°C to the conventional binder. Based on the modified binder fabrication approaches and the addition of sulfur, four categories of modified binders were prepared, namely sequential (SA), sequential with sulfur (SA-S), pre-swelled (PA), and pre-swelled with sulfur (PA-S). For variable modifier dosages (EPDM:16%, PPO: 2, 4, 6, and 8%, and sulfur: 0.3%), a total of 17 combinations of rubberized asphalt were subjected to two durations of thermal storage (48 and 96 hours) and then characterized for their storage stability performance through various separation indices (SIs) based on conventional, chemical, microstructural, and rheological analyses. The optimal storage stability performance was achieved at a PPO dosage of 6% under the four candidate approaches. It was also observed that the SIs based on chemical analysis and rubber extraction test had a good correlation with rheology-based SIs compared to the conventionally used softening point difference. A composite modified binder with PPO and EPDM rubber having adequate storage stability is a promising step in the use of sustainable composite-modified binders in asphalt pavement construction.

ОБЕСПЕЧЕНИЕ ТЕХНОСФЕРНОЙ БЕЗОПАСНОСТИ ПРИ ПРОИЗВОДСТВЕ ЭМУЛЬСИОННЫХ КАУЧУКОВ

Synthetic polymer materials are in high demand due to their exceptional properties. Their main consumers are the tire and rubber industries. When producing synthetic rubbers, there is a loss of polymer in the form of fine crumb rubber, which is formed at the final stage of their production. Today, the removal of this crumb from the wastewater of latex rubber extraction plants is an urgent issue. The results of a study on the extraction of fine rubber crumbs are presented. The task is solved by using an apparatus for separating water phases in the technology, which allows more complete and rational use of expensive products of chemical and petrochemical production, increase productivity and environmental friendliness of production, which leads to an increase in technosphere safety in general. The optimal flow rates of aqueous phases passed through the spiral belt of the filter element, which is 15–25 m/s, have been determined. The separated water stream containing concentrated fine rubber crumb is returned to the styrene-butadiene latex coagulation stage. The purified water phase after the filter element is collected in a separate collector and used to prepare solutions of coagulating and acidifying agents. The additional introduction of finely dispersed rubber crumbs into the composition of the resulting coagulum do not lead to a deterioration in the basic physical and mechanical properties of the resulting rubbers and vulcanizates. The proposed method for industrial wastewater treatment improves safety in the technosphere.

Application of brewing waste in the technology of synthetic polymers

At present, much attention is paid to the production of synthetic polymers. The production of rubbers by emulsion polymerization is of particular interest. Sodium chloride, currently used as a coagulating agent, has a high consumption of up to 200 kg / t of rubber and increases environmental pollution. In the presented work, for the first time, the possibility of using dispersed systems of brewing waste (yeast) to reduce the aggregate stability is considered. The use of waste material in the technology of extracting rubber from latex makes it possible to exclude sodium chloride from the technological cycle. The use of a system based on a protein coagulant makes it possible to achieve complete separation of rubber from latex at a waste consumption of 10-15 kg / t of rubber. The best results were achieved when yeast pre-acidified with sulfuric acid was used in this process, which leads to charging the nitrogen atom of the protein component. It was noted that the best temperature regime for the process of rubber extraction from latex is 1-20 ° C. An increase in temperature to 60 ° C leads to an increase in the consumption of coagulant by 5 kg / t of rubber. According to all the main physical and mechanical indicators, rubbers isolated by this technology meet the requirements.

PROCESS OPTIMIZATION OF GREEN AQUEOUS-BASED EXTRACTION TECHNOLOGY OF TARAXACUM KOK-SAGHYZ RUBBER

ABSTRACT Taraxacum kok-saghyz (TKS), known as Russian dandelion, can produce high-quality natural rubber. The dry weight content of rubber in the TKS roots was found to be approximately 6–9%, of which 61% and 39% were stored in the root bark and root flesh, respectively. The content of lignin and holocellulose accounted for about 40% of the total root. Two new aqueous-based rubber extraction processes were proposed and optimized, namely, the strong water shearing process and the acid–base extraction process. These two processes made the purity of rubber reach about 91% and 94%, respectively. TKS rubber was characterized as having similar composition, and molecular structure to Hevea NR, and TKS rubber samples did not exhibit the strain-induced crystallization (SIC) phenomenon. TKS rubber was blended into a winter tire tread formulation and tested. The results showed no significant differences in processing and mechanical properties from the other formulations.

Chemical characterization, antioxidant activity and morphological traits in the leaves of guayule (Parthenium argentatum A. Gray) and its hybrids

In the rubber extraction process, guayule leaves represent an important biomass waste by-product, up to 32%, whose exploitation might contribute to the valorization of the whole plant. The extraction of any of its bioactive compounds or its use as an antioxidant seems to be the most feasible alternative. This study relates guayule leaves morphology to the individual content of 35 compounds (of the 50 tentatively identified), the determination of overall phenolic content and antioxidant activity. The morphological traits allowed the classification of the accessions (27) into three main groups according to size and shape of the leaf, being related to their hybridization. The environment and growing conditions modified the leaf phenotype for USDA germplasm with respect to recent USA studies. The heterogeneity found by different authors in the determination of phenolic content in guayule leaves requires a standardization procedure. Of the two analysis protocols, Total Polyphenol Index (TPI) and Folin–Ciocalteau reagent (Folin) after extracting the leaves at 1 and 24 h, the TPI at 1 h was selected since it was faster and simpler than others and correlated better with the antioxidant activity determined by 2,2-diphenyl-picrylhydrazyl (DPPH). The compounds found in greater quantities corresponded to the chlorogenic acid family, but with no influence with leaf morphology. On the other hand, compounds with smaller concentrations such as gallic acid, an isomer of ferulic acid or the quercetagetin methyl ether glucuronide correlate with aspects of leaf morphology.

Guayule stems fractionation and sugars recovery by different pretreatment technologies

The bagasse of guayule, obtained after extraction of natural rubber and resins, can be used to produce 2nd generation fermentable sugars and lignin. For this purpose, four pretreatment technologies were applied to deconstruct the guayule bagasse: diluted acid (DA), steam explosion (SE), organosolv (OS), and the steam explosion followed by alkaline washing (AW). The obtained lignocellulosic pulp underwent enzymatic hydrolysis (EH) to produce glucose. The conditions that gave the highest hydrolysis yield were assessed. A mass balance was elaborated for all processes which were compared on the basis of sugars yield, water and chemical consumption, and energy expenditure footprint. The greatest amount of glucose (133 g kg−1 of dry guayule bagasse, corresponding to 71% enzymatic hydrolysis yield) was obtained using SE followed by AW, whereas SE and OS had lower yields (104 g and 106 g kg−1, respectively). The highest overall monomeric sugars yield, including xylose, was obtained by DA (317 g kg−1) followed by OS (243 g kg−1) pretreatment, although the sugar streams must be purified in both processes by removing the acid and the solvent, respectively. SE is a process with a limited requirement of chemicals and energy input, which are significantly higher for AW and for OS, respectively.

Fast Determination of the Rubber Content in Taraxacum kok-saghyz Fresh Biomass Using Portable Near-Infrared Spectroscopy and Pyrolysis–Gas Chromatography

Taraxacum kok-saghyz (TKS) is a plant native to the Tianshan valley on the border between China and Kazakhstan. TKS rubber is a good substitute for natural rubber. TKS's breeding work necessitates the need to screen high-yielding varieties, hence rapid determination of rubber content is essential for the screening. Conventional analytical methods cannot meet actual needs in terms of real-time testing and economic cost. Near-infrared spectroscopy analysis technology, which has developed rapidly in the field of industrial process analysis in recent years, is a green detection technology with obvious merits of fast measurement speed, low cost and no sample loss. This research aims to develop a portable non-destructive near-infrared spectroscopic detection scheme to evaluate the content of natural rubber in TKS fresh roots. Pyrolysis gas chromatography (Py-GC) was chosen as the reference method for the development of NIR prediction model. 208 TKS fresh root samples were collected from the Inner Mongolia Autonomous Region of China. Near-infrared spectra were acquired for all samples. Randomly, two-thirds of them were selected as the calibration set, the remaining one-third as the validation set, and the partial least squares method was successfully established a good NIR prediction model for rubber content at 1080–1800 nm with a ratio of performance to deviation (RPD) of 5.54 and coefficient of determination (R2) of 0.95. This study showed that portable near-infrared spectroscopy could be used with ease for large-scale screening of TKS plants in farmland, and could greatly facilitate TKS germplasm preservation, high-yield cultivation, environment-friendly, high-efficiency and low-cost rubber extraction, and comprehensive advancement of the natural rubber industry thereof.

Alkaline pretreatment of Taraxacum kok-saghyz (TK) roots for the extraction of natural rubber (NR)

Natural rubber (NR) is an essential biomaterial the supply of which is insecure. Taraxacum kok-saghyz (TK), a rubber-producing dandelion, is an alternative source of NR that has excellent potential for commercial development. Scalable methods for rubber extraction at high yield, quality and purity are needed to meet this potential. We previously developed an aqueous, enzymatic method for the extraction and purification of NR from TK roots. Alkaline pretreatment significantly improved the yield of TK NR using this method, but its effects on NR yield, purity and quality at a range of base concentrations and temperatures was not tested. In this study, TK roots (after inulin extraction) were pretreated at sodium hydroxide loading rates of 0, 33, 66 and 132 mg NaOH/g and temperatures of 25, 70, 125 and 160 °C. Treatment with pectinase and cellulase enzymes was used to solubilize root structural carbohydrates and liberate NR. Rubber quality and impurities were then characterized. Results showed that increasing NaOH loading rate and temperature significantly improved rubber yield, but reduced rubber molecular weight and rubber gel content. Rubber purity and thermal properties were largely unaffected by pretreatment conditions. FTIR and SEM analysis revealed that alkaline pretreatment primarily altered protein and other secondary components of TK NR.

REDUCING THE AGGREGATIVE STABILITY OF EMULSION STYRENE BUTADIENE RUBBER WITH THE USE OF AROMATIC AMINES

In this paper, for the first time, a study was conducted on the use of various types of aro-matic amines in the production of emulsion rubbers to reduce the aggregative stability of latex dispersions. The use of aromatic hydrocarbons containing amine groupsin the technology of sep-aration of rubber from latex makes it possible to obtain emulsion rubbers at low costs of the coag-ulating agent. It was found that the temperature regime of the coagulation process of the latex system has a significant effect on the consumption of aromatic amines used: the lowest consump-tion was noted when using them to reduce the aggregate stability of latex systems at temperatures not exceeding 20 °C. The consumption of the acidifying agent -15 kg/t of rubber. Low amounts of coagulating agent create good prerequisites for the implementation of a closed technological cycle on an industrial scale, reducing water consumption by rubber extraction workshops from latex, which ultimately increases the environmental friendliness of the entire technological process of their production. The analysis of rubbers as well as the physical and mechanical characteristics of vulcanizates prepared on their basis, showed that the main properties of rubber-technical products, from control and experimental samplescomply with the regulatory requirements of GOST and TU.

Determination of the correlation between the accumulation of pigments and natural rubber in Tau-saghyz

Natural rubber is a valuable polymer used in a wide variety of industries, from tire manufacturingto medical products and applications in the food industry. The tau-sagyz rubber plant (Scozonera tausaghyzLipcsh et Bosse) is one of the few plants in the world that can be used in the production of naturalrubber when cultivated in culture. To increase the productivity of plants, it is necessary to establish factorsaffecting the biosynthesis of natural rubber. In our studies, the level of pigments (chlorophyll–a, b, carotenoids)was chosen as a factor that may have a positive effect on the accumulation of rubber in the roots ofS. tau-saghyz. For this purpose, samples (leaves, roots) were taken from 3 groups of plants (north, south,east) in the Karatau mountains of the Kurman-Tas range. The extraction of pigments from leaf samples wascarried out with acetone, and the extraction of rubber from the roots was carried out with hexane. The obtaineddata on the content of pigments and rubber in the samples were statistically processed using the t-testand Pearson correlation analysis. As a result, a statistical difference in the values of pigment accumulationin leaves and rubber in roots between the 3 studied groups of plants is shown. On the other hand, a very lowlevel of correlation was found between the accumulation of pigments in the leaves and rubber in the roots inall three groups. The obtained results reliably showed that the level of pigment accumulation in the leavesdoes not affect the accumulation of rubber in the roots of Tau-sagyz.

EXTRACTION OF RUBBER FROM LATEX BY HYBRID COAGULANT BASED ON POLYDIMETHYLDIALLYLAMMONIUM CHLORIDE AND VISCOSE FIBER

In the proposed work, the possibility of using a hybrid coagulant based on a polymer cationic electrolyte-VPK – 402 (poly-N,N-dimethyl-N, N-diallylammonium chloride) in combination with viscose fiber in the technological process of separating SKS-30 ark rubber from latex is considered. The influence of the consumption of a hybrid coagulating agent, viscose fiber and its dosage, as well as the process temperature on the reduction of the aggregate stability of styrene-butadiene latex is considered. The influence of viscose fiber on the physical and mechanical properties of vulcanizates is established. At the same time, a number of features were noted consisting in a decrease in the aggregate stability of latex butadiene-styrene rubber during its coagulation with a hybrid coagulant. It was found that the use of a hybrid coagulant can reduce the consumption of cationic polyelectrolyte by up to 30%. It is shown that in the multicomponent system under consideration, several processes can occur simultaneously, which lead to the destabilization of latex dispersions. The use of a hybrid coagulant, including cationic polyelectrolyte, provides a combined effect of the bridging and neutralization mechanisms of violation of the aggregate stability of the dispersion. The presence of viscose fiber in the dispersed phase leads to an additional coagulating effect-adagulation, which is a kind of heterocoagulation. This may be due to the difference in surface potentials between the latex globules and the fiber additive. It is established that the temperature regime of the process of isolation of rubber from latex does not significantly affect the completeness of the extraction of rubber from latex. A decrease in the content of components of the emulsion system in wastewater discharged from the shops producing rubbers by emulsion polymerization was noted. According to the main physical and mechanical parameters, rubbers, rubber mixtures and vulcanizates prepared on their basis meet the requirements.