scholarly journals Comparison of Morphological Characteristics and Determination of Different Patterns for Rubber Particles in Dandelion and Different Rubber Grass Varieties

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1561
Author(s):  
Boxuan Yuan ◽  
Guohua Ding ◽  
Junjun Ma ◽  
Lingling Wang ◽  
Li Yu ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Morphological Characteristics ◽  
Leaf Margin ◽  
Rubber Content ◽  
Flower Buds ◽  
Promising Alternative ◽  
Alternative Crop ◽  
Rubber Particles ◽  
Common Dandelion

Russian dandelion Taraxacum kok-saghyz (TKS) is one promising alternative crop for natural rubber production. However, it is easily confused with other dandelions. In this study, we performed a systematical comparison of the morphological characteristics for different TKS varieties and common dandelion Taraxacum officinale (TO). Our results demonstrated that several obvious differences in morphology can be found between TKS and TO. TO leaf is a pinnate shape, its margin is heavily jagged and its base is cuneate, but TKS leaf is more cuneate and its leaf margin is nearly smooth and round. There are obvious differences for the outer bracts of TO and TKS flower buds. TKS bracts are oblanceolate, apex obtuse, margin smooth and sinuate, and its outer layer of flower buds and faceplate involucre sepal is buckled inward to form a certain angle. TKS is self-incompatible, and its seeds are spindle-shaped achene and show upright plumpness. A large amount of laticifer cells and rubber particles can be detected from many TKS tissues, and dry roots of TKS contain high contents of natural rubber. Laticifer cells and rubber particles can only be examined in the vein, stem, and roots of TKS. Our statical results also revealed that the numbers of laticifer cells and rubber particles have a positive relationship with the rubber content in TKS roots. These morphological features can help us to easily distinguish TKS from common dandelion and approximately estimate the rubber content in the roots of different TKS varieties for TKS breeding in future.

scholarly journals Fast Determination of the Rubber Content in Taraxacum Kok-Saghyz Fresh Biomass Using Portable Near Infrared Spectroscopy and Pyrolysis-Gas Chromatography

2021 ◽  
Author(s):  
Ying Chen ◽  
Dong Yiyang ◽  
Xiang Ma ◽  
Jiaru Li ◽  
Minmin Guo ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Infrared Spectroscopy ◽  
Natural Rubber ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Low Cost ◽  
Rubber Content ◽  
Pyrolysis Gas ◽  
Pyrolysis Gas Chromatography

Abstract Background: Taraxacum kok-saghyz (TKS), a plant native to the Tianshan valley on the border between China and Kazakhstan and inherently rich in natural rubber, inulin and other bioactive ingredients, is an important industrial crop. 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 (PyGC), was chosen as the reference method for the development of NIR prediction model. Results: 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 verification set, and the partial least squares method was successfully used to establish a good NIR prediction model at 1080-1800nm with a performance to deviation ratio (RPD) of 5.54 and coefficient of determination (R2) of 0.95. Conclusions: 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 dandelion rubber industry thereof.

Microturbidimeter for Determination of Rubber Content of Latex

1931 ◽  
Vol 4 (4) ◽  
pp. 601-611
Author(s):  
S. D. Gehman ◽  
J. S. Ward
Keyword(s):  
Particle Size ◽  
Rubber Content ◽  
Mean Particle Size ◽  
Rubber Particles ◽  
Color Filters

Abstract It is desirable to devise a method for determining the dry rubber content of latex which will be both more rapid than the two trial coagulation methods and more precise than the hydrometric method. The turbidity of latex, depending upon the volumetric number and size of the suspended rubber particles, offers a satisfactory criterion for the determination of the rubber content of latex. A microturbidimeter, herein described, has been adapted to such determinations. It permits more rapid determinations of the rubber content than the two trial coagulation methods. Its precision is less than the lengthy trial coagulation method, involving coagulation, creping, and drying, but is probably greater than that of the shortened trial coagulation method involving only coagulation and creping. Its precision is approximately 1 per cent rubber in 35 per cent latex. The turbidity of latex obeys the turbidity-dilution law for rubber-content values less than 15 per cent. The use of color filters, transmitting the shorter wave lengths of light, minimizes the effects of a difference in the effective mean particle size of different kinds of latex.

Ozonolytic Degradation of Interpolymers of Natural Rubber with Methyl Methacrylate and Styrene

1958 ◽  
Vol 31 (1) ◽  
pp. 82-85
Author(s):  
D. Barnard
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Natural Rubber ◽  
Accurate Determination ◽  
Synthetic Polymers ◽  
Polymer Chains ◽  
Low Molecular Weight ◽  
Rubber Content ◽  
Tert Butyl Hydroperoxide

Abstract The preparation of graft and block interpolymers of natural rubber and synthetic polymers has made it desirable that the number and size of polymer chains attached to rubber be readily determinate. The degradation of unsaturated polymers with tert-butyl hydroperoxide in the presence of osmium tet oxide has been used for the determination of free polystyrene in SBR and carbon black in several elastomers, and has recently been applied to the present problem. The accurate determination of the rubber content of interpolymers by quantitative ozonolysis essentially according to the method of Boer and Kooyman suggested that this might be made the basis of isolation of the attached polymer, the rubber being degraded into fragments of low molecular weight, from which the polymer could be separated by conventional techniques. The method should be applicable to any interpolymer, or mixture, of a polyunsaturated and a saturated polymer and is illustrated with reference to interpolymers of natural rubber (NR)-polymethyl methacrylate (PMM) and NR-polystyrene (PS).

COMPARATIVE ANALYSIS OF 14C AND TGA TECHNIQUES FOR THE QUANTIFICATION OF THE BIOMASS CONTENT OF END-OF-LIFE TIRES

2014 ◽  
Vol 87 (4) ◽  
pp. 664-678 ◽  
Author(s):  
Leticia Saiz-Rodríguez ◽  
José María Bermejo-Muñoz ◽  
Andrés Rodríguez-Díaz ◽  
Alberto Fernández-Torres ◽  
Antonio Rubinos-Pérez
Keyword(s):  
Thermogravimetric Analysis ◽  
Stearic Acid ◽  
Natural Rubber ◽  
End Of Life ◽  
Rubber Content ◽  
Thermogravimetric Method ◽  
Precise Method ◽  
Different Types ◽  
Reference Samples

ABSTRACT Thermogravimetric analysis (TGA) and 14C techniques were compared for the determination of the biomass content of end-of-life tires (ELTs). Samples of different types (of ELTs) were prepared, and the biomass fraction of each sample was measured using the two methods (TGA and 14C). Six reference samples were also prepared with known quantities of natural rubber and stearic acid in order to establish the calibration curve necessary for the thermogravimetric analysis and to verify the accuracy of the results of the 14C analysis. The conclusions were that the 14C technique is the more valid, reliable, and precise method for determining the biomass content of end-of-life tires, since the results of the 14C tests of the reference samples coincided perfectly with the actual natural rubber and stearic acid content. On the other hand, the results of the thermogravimetric method differed considerably from the known natural rubber content of the reference samples as well as from the results of the 14C technique. This method is therefore not appropriate for use in determining the biomass content of end-of-life tires.

A New Rubber Particle Count in Hevea Latex

1936 ◽  
Vol 9 (4) ◽  
pp. 644-647
Author(s):  
Earle E. Langeland
Keyword(s):  
Original Work ◽  
Rubber Particle ◽  
Fundamental Property ◽  
The Other ◽  
Rubber Content ◽  
Microscopic Method ◽  
Particle Count ◽  
Rubber Particles ◽  
The One

Abstract SO MUCH confusion has grown up in the literature concerning the number of rubber particles in Hevea latex that at the present time there exists a thousandfold error in the currently published reports (1, 3, 8) of the one original determination of this number. Harries (4), Hauser (5), and Noble (8), each reporting the original work of Henri (6), give a count of 50,000,000 particles per cubic centimeter of latex, Harries not specifying the concentration, while Hauser and Noble indicate it to have been 8.7 per cent solids. On the other hand, Dubosc and Luttringer (2), also reporting the work of Henri, record a count of 50,000,000 particles per cubic millimeter in latex of unspecified concentration. The original paper of Henri (6) reported that he had found an average of 50,000,000 particles per cubic millimeter of latex having a specific gravity of 0.973 and containing 8.7 grams of solids per 100 cc. Preliminary counts undertaken by the author with a view to developing a rapid microscopic method for the determination of the dry rubber content of latex indicated that the results of Henri were considerably low. Since the number of microscopically visible particles is a fundamental property of latex, it was felt that a redetermination of this number would be of value.

An Infrared Spectrophotometric Analysis for Natural Rubber in Guayule Shrubs

1982 ◽  
Vol 55 (2) ◽  
pp. 407-415 ◽  
Author(s):  
T. F. Banigan ◽  
A. J. Verbiscar ◽  
T. A. Oda
Keyword(s):  
Los Angeles ◽  
Gravimetric Method ◽  
Spectrophotometric Analysis ◽  
Photometric Method ◽  
Plant Tissues ◽  
Aqueous Alcohol ◽  
Rubber Content ◽  
Rubber Particles ◽  
Controlled Precipitation

Abstract An accurate assay of rubber content in guayule plant tissues is essential to any genetic improvement or bioregulator program. The simpler, more rapid and less expensive the assay, the better. The several methods of rubber assay that have been used have various limitations. Earlier methods for assaying rubber content in guayule are described in two USDA reports. These are principally gravimetric methods which are tedious and relatively nonselective. One of the better ones consists in bromination of the guayule double bonds, precipitation from solution, collection, drying, and weighing the crystalline rubber bromide. This bromide method is more selective for rubber in the presence of resins than the gravimetric methods where rubber is weighed directly. For multiple and repetitive analyses, it is time consuming and somewhat unpleasant due to the recommended excess of bromine. A gravimetric method reported by Tysdal in 1951 was modified recently. The method consists of grinding guayule shrub in an efficient blender with aqueous alcohol saturated with salt. The resulting slurry is screened to recover resinous rubber particles, which are dried and weighed. Precision is considered adequate for distinguishing plants of widely differing rubber content but not for detecting incremental changes. Another rubber assay of merit is the photometric method of Traub. This volumetric method depends upon a controlled precipitation of rubber particles from solution and the determination of rubber quantity by photometric measurement of the resulting turbidity. It is being used with some modifications on a guayule breeding project at the Los Angeles State and County Arboretum Research Laboratory. The principal improvement consists in extracting the rubber from the plant tissue by homogenizer milling in solvent rather than lengthy soxhlet extractions.

Determination of Rubber Hydrocarbon by a Gravimetric Rubber Bromide Method

1947 ◽  
Vol 20 (1) ◽  
pp. 320-328 ◽  
Author(s):  
C. O. Willits ◽  
M. L. Swain ◽  
C. L. Ogg
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Difference Method ◽  
Direct Determination ◽  
Chemical Processes ◽  
Rubber Content ◽  
Low Concentration ◽  
Hydrocarbon Analysis ◽  
The Difference

Abstract Direct determination of rubber hydrocarbon in crude rubbers and in latices has been generally considered so inaccurate and unreliable that determination of rubber hydrocarbon by difference has been a common practice. The difference method usually suffices in the analysis of products derived from Hevea rubber, in which the nonrubber components have been well characterized or occur in low concentration. In the analysis of natural rubber products obtained from sources other than Hevea, such as guayule, kok-saghyz, and Cryptostegia, the situation is different. The chemical and physical properties of the nonrubber components of such products are largely unknown, and in many cases the nonrubber contaminants are present in excessive amounts, sometimes more than 50 per cent of the total. Since the rubber hydrocarbon analysis usually affords the most reliable means for estimating the rubber content of plants and for following the concentration and purification of rubber by mechanical and chemical processes, it appeared desirable to devise or adapt a method which would permit direct determination of this constituent in the presence of relatively large amounts of natural and added contaminants.

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