Microwave Devulcanization of Waste Rubber with Inorganic Salts and Nitric Acid

2011 ◽  
Vol 418-420 ◽  
pp. 1072-1075 ◽  
Author(s):  
Glauco Dias Paulo ◽  
Denise Hirayama ◽  
Clodoaldo Saron
Keyword(s):  
Nitric Acid ◽  
Carbon Black ◽  
Soxhlet Extraction ◽  
The Other ◽  
Inorganic Salts ◽  
Metallic Ions ◽  
Chemical Modifications ◽  
Mechanical Recycling ◽  
Vulcanized Rubber ◽  
Waste Rubber

Rubber wastes cause severe damages for the environment when unsuitably disposed in the environment and represent a challenger for mechanical recycling, because the vulcanized rubber is formed by a tridimensional network with intermolecular sulfur crosslinks. Microwave radiation can lead to the breaking of sulfur crosslinks and so enable the recycling of vulcanized rubbers. The aim of this work was to study the SBR devulcanization by microwave using inorganic salts and nitric acid. Soxhlet extraction and FTIR analyzes were carried out to evaluate the devulcanization degree and chemical modifications in the rubber structure. The results showed that the presence of carbon black in the rubber is an important factor for devulcanization and some metallic ions decrease the sulfur crosslink content. On the other hand, these ions promote the oxidation in the rubber.

Studies on the Joule Effect in Rubber. I. The Thermal Effect on Stretched Vulcanized Rubber

1935 ◽  
Vol 8 (2) ◽  
pp. 174-176
Author(s):  
Yoshio Tanaka ◽  
Shū Kambara ◽  
Hironosuke Fujita
Keyword(s):  
Carbon Black ◽  
Thermal Effect ◽  
Ultra Violet ◽  
Sulfur Compounds ◽  
The Other ◽  
Joule Effect ◽  
Ultra Violet Radiation ◽  
Vulcanized Rubber ◽  
High Heating ◽  
Violet Radiation

Abstract The experiments may be summarized as follows: 1. With an increase in the time of cure, the elongation and heating elongation diminish and the Joule effect increases. 2. An increase in the vulcanization coefficient is followed by a decrease in the elongation and heating elongation and an increase in the Joule effect. The increase in the Joule effect, however, has a limit. 3. An organic accelerator reduces the elongation and heating elongation and increases the Joule effect. 4. The greater the degree of mastication the greater the elongation and the heating elongation and the less the Joule effect. 5. By exposure to ultra-violet radiation, the elongation and heating elongation are increased and the Joule effect decreased. 6. A filler increases the heating elongation and decreases the elongation and the Joule effect. Thus samples with relatively high elongations at a definite tension have relatively high heating elongations and low Joule effects. Such specimens seem to have been affected by the disaggregation and depolymerization of the rubber molecules. The effects of the time of cure, mastication, and exposure to ultra-violet radiation prove this fact. Vulcanization increases the Joule effect, but on the other hand, it is accompanied by a disaggregation and depolymerization of the rubber molecules, so the increase in the Joule effect with the progress of vulcanization has a limit. On vulcanization with an accelerator, the combination of sulfur occurs so rapidly that the increase in the Joule effect is predominant. A filler, such as carbon black, behaves only as a diluent of Joule effect. These results lead to the conclusion that the more highly polymerized rubber molecules and their sulfur compounds seem to be the chief factor in the Joule effect of vulcanized rubber.

Determination of Free Carbon in Cured Rubber Stocks

1951 ◽  
Vol 24 (1) ◽  
pp. 224-227
Author(s):  
I. M. Kolthoff ◽  
R. G. Gutmacher
Keyword(s):  
Nitric Acid ◽  
Carbon Black ◽  
Natural Rubber ◽  
Osmium Tetroxide ◽  
Free Carbon ◽  
Vulcanized Rubber ◽  
Tert Butyl Hydroperoxide ◽  
Inorganic Fillers ◽  
Dilute Nitric Acid

Abstract A method for the determination of free carbon in vulcanized rubber stocks is described. The sample is softened in boiling p-dichlorobenzene before treatment with tert-butyl hydroperoxide in the presence of osmium tetroxide. No difficulties are encountered in the filtration of the carbon black. The carbon black is washed on the filter with dilute nitric acid to remove acid-soluble inorganic fillers. The method has been successfully applied to natural rubber, GR-S, Butyl rubber, and Neoprene. No correction is necessary.

Estimation of Carbon Black in Neoprene Compounds

1941 ◽  
Vol 14 (3) ◽  
pp. 752-753 ◽  
Author(s):  
J. R. Scott ◽  
W. H. Willott
Keyword(s):  
Nitric Acid ◽  
Carbon Black ◽  
Steam Bath ◽  
Usual Method ◽  
Muffle Furnace ◽  
Hot Plate ◽  
Vacuum Desiccator ◽  
Vulcanized Rubber ◽  
The Difference ◽  
Pass Through

Abstract During a recent investigation it was necessary to determine the amount of carbon black in a sample of vulcanized Neoprene. The usual method adopted for vulcanized rubber, which consists in dissolving the rubber in nitric acid (British Standard Methods of Testing Vulcanized Rubber, B.S. 903–1940, p. 28), was tried without success, as the Neoprene did not dissolve. No methods for the analysis of Neoprene compounds appear to have been described in the literature; the following method of estimating carbon black, which has been found to work satisfactorily, may therefore prove of interest, especially as it can be used for certain other synthetic rubbers such as Buna. About 1.0 gram of the Neoprene sample is reduced to a fine crumb, such as will pass through a B.S. 10-mesh test sieve, by means of a rapidly rotating rasp. After extraction with acetone and chloroform, the extracted material is dried in a vacuum desiccator, transferred to a 400 cc. beaker, 20 cc. of nitrobenzene added, and the whole heated on a hot plate for a few minutes to allow the Neoprene to swell. 20 cc. of 25 per cent nitric acid (25 volumes of conc. nitric acid and 75 volumes of water) are then added, and the beaker is replaced on the hot plate. The Neoprene disintegrates and dissolves in the nitrobenzene in a few minutes. The beaker is then heated on a steam bath for about an hour, after which 100 cc. of xylene is added and the mixture filtered, while hot, through an alundum crucible or prepared Gooch crucible. The carbon is carefully washed with hot xylene till free from decomposed Neoprene, and finally with acetone. After drying at 150° C, the crucible is weighed, the carbon black then burnt off in a muffle furnace, and the crucible reweighed. The difference between these weights is the amount of carbon black present.

Extraction of iron, cobalt, nickel and copper with dibenzyl sulfoxide solution in toluene

1979 ◽  
Vol 44 (7) ◽  
pp. 2024-2031 ◽  
Author(s):  
František Vláčil ◽  
Huynh Dang Khanh
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Distribution Ratio ◽  
Separation Factor ◽  
Chromatographic Separation ◽  
The Other ◽  
Iron Cobalt ◽  
Cobalt Nickel ◽  
Factor Α

The dependence of the distribution ratio of the metal on the concentration of hydrochloric of nitric acid was examined for Fe, Co, Ni and Cu extraction with 0.05M solution of dibenzylsulfoxide in toluene. Iron is extracted considerably more than the other metals, and is better extracted from hydrochloric acid than from nitric acid. The separation factor αFe/M (for 8M-HCl) is of the order of 104; this is not sufficient for a separation of trace quantities of iron from Co, Ni and Cu, but even at lower concentrations of HCl (e.g., 5M) the values is high enough for extraction chromatographic separation. The composition of the iron solvate extracted from HCl or LiCl medium was determined to be HFeCl4.2 B (B = dibenzyl sulfoxide).

scholarly journals IX. The electric conductivity of nitric acid

1898 ◽  
Vol 191 ◽  
pp. 365-398 ◽  
Keyword(s):  
Nitric Acid ◽  
Physical Properties ◽  
Nitrous Acid ◽  
Internal Resistance ◽  
The Other ◽  
Reasonable Degree ◽  
Mineral Acids ◽  
Artificial Illumination ◽  
The Subject ◽  
Deep Green

Of the commoner mineral acids the chemical changes of Nitric Acid, from their evident complexity, have formed the subject of numerous memoirs, while those of sulphuric acid, from their assumed simplicity, have been to some degree neglected; on the other hand, the physical properties of the latter have been studied with considerable elaboration, while those of the former have been passed over, doubtless on account of the corrosive nature of the acid and the difficulty of preparing and preserving it in a reasonable degree of purity. Further, with certain exceptions, the alterations in physical properties induced by the products of reduction, be they nitrogen peroxide or nitrous acid, either singly or conjointly, have attracted but little attention, though it is a common matter of observation that the current intensity of a Grove’s or other cell containing nitric acid remains constant, even though the fuming acid, originally colourless or red, has become of a deep green tint. It is more than probable that of the factors of Ohm’s law, both the E. M. F. and internal resistance are continually varying. At the earliest stages of the enquiry it was found that the passage of a few bubbles of nitric oxide gas into a considerable volume of nitric acid produced an alteration of one percent, in the resistance, and the same result could be effected to a less degree by exposure to sunlight, and to a still less degree by exposure to artificial illumination. Therefore, we determined to investigate the alterations of conductivity produced by changes of concentration and temperature in samples of acid purified with necessary precautions, more especially as former workers upon the subject have either used samples of acid confessedly impure, or have been silent as to any method of purification, or have adopted no special care in dealing with a substance so susceptible of polarisation.

scholarly journals The Dissociation of the Compound of Iodine and Thio-urea

1904 ◽  
Vol 24 ◽  
pp. 233-239 ◽  
Author(s):  
Hugh Marshall
Keyword(s):  
Nitric Acid ◽  
General Formula ◽  
Free Acid ◽  
The Other ◽  
Image Position

When thio-urea is treated with suitable oxidising agents in presence of acids, salts are formed corresponding to the general formula (CSN2H4)2X2:—Of these salts the di-nitrate is very sparingly soluble, and is precipitated on the addition of nitric acid or a nitrate to solutions of the other salts. The salts, as a class, are not very stable, and their solutions decompose, especially on warming, with formation of sulphur, thio-urea, cyanamide, and free acid. A corresponding decomposition results immediately on the addition of alkali, and this constitutes a very characteristic reaction for these salts.

Carbon Black. I—A Study of Its Volatile Constituents

1928 ◽  
Vol 1 (3) ◽  
pp. 485-497 ◽  
Author(s):  
C. R. Johnson
Keyword(s):  
Carbon Black ◽  
Volatile Matter ◽  
Original Sample ◽  
Missing Information ◽  
Volatile Constituents ◽  
Vulcanized Rubber ◽  
Rates Of Evolution ◽  
Temperature And Pressure ◽  
The Relationship

Abstract The rates of evolution of gas from carbon black with variation of time, temperature, and pressure have been determined. Complete analyses have been made of five types of carbon black, which involve an organic combustion of the original sample, an organic combustion of the sample after the gases have been removed, a determination of the loss in weight represented by the gases removed, analyses of the gases removed, and finally a complete accounting, or balance, of the carbon in the steps considered. In an attempt to supply some missing information not revealed by the foregoing, some special gas analyses under varying conditions were made. The relationship between the amount and composition of volatile matter evolved from carbon blacks and the properties imparted to vulcanized rubber when compounded with these blacks has been studied.

scholarly journals Pengolahan Limbah Kulit Durian dan Baterai Bekas Menjadi Salah Satu Sumber Energi Listrik yang Ramah Lingkungan

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Muhammad Gifron ◽  
Nelmi Agustina ◽  
Doris Wela
Keyword(s):  
Alternative Energy ◽  
Organic Waste ◽  
Plastic Waste ◽  
The Other ◽  
Basic Material ◽  
The Sun ◽  
Environmental Friendly ◽  
Waste Rubber ◽  
The World ◽  
Parallel Circuit

Abstrak. Seiring dengan bertambahnya jumlah penduduk dunia, selalu diiringi oleh masalah limbah yang berasal dari sampah, baik sampah organik maupun non organik. Berbagai usaha untuk mengatasi masalah limbah tersebut secara berkesinambungan terus dilakukan , baik itu sampah-sampah anorganik seperti, berbahan plastik, karet dan lain-lain. Bisa dimanfaatkan kembali melalui daur ulang menjadi barang-barang kebutuhan harian. Sedangkan untuk sampah organik selain dimanfaatkan untuk pupuk, juga dapat digunakan sebagai bahan dasar pengisi baterai untuk menghasilkan energi alternatif yang ramah lingkungan. Terkhususnya untuk pemanfaatan limbah organik dalam pembuatan baterai telah dilakukan dengan beda potensial tertinggi yang dihasilkan adalah 1,67 volt. Dalam penelitian ini dilakukan modifikasi massa bahan pengisi baterai yang bersumber dari kulit durian yang yang diproses khususnya melalui pengeringan menggunakan oven serta dicampur dengan asam dan ada juga kulit durian yang dijemur selama 7 hari dengan massa kulit durian 3, 5, dan 10. Beda potensial baterai tertinggi yang didapatkan adalah 10 gram yaitu sebesar 1,67 volt. Selanjutnya baterai dengan massa 10 gram difabrikasi dalam jumlah tertentu yang digunakan untuk menyalakan LED. Baterai tersebut dirangkai baik secara seri maupun paralel untuk menghasilkan beda potensial yang bervariasi. Abstract. Along with the growing number of the world populations, there always followed by troubles waste derived from trash, organic waste, and non-organic waste. Many attempts to deal with an organic waste such as plastic waste, rubber, and etc, has been continued, so those waste can be recycled and reused for daily demand. On the other hand, organic waste can be used as fertilizer, and basic material for the battery that results an environmental friendly alternative energy. Especially to utilize the organic waste, the making of battery has been done that yields highest voltage, 1.67 volts. This research aims to modify the mass filler of the battery that obtained from durian skin which is processed by mixing it with acid and drying it using oven, there also other technique by drying the durian skin under the sun for about 7 days which varied masses of 3 gram, 5 gram, and 10 gram. The highest voltage that obtained is 1.67 volt using 10 gram durian skin. Further, the battery with 10 grams durian skin is then fabricated in a specified number to light up the LED. This battery placed either in serial or parallel circuit to obtain varied voltage.

The Effects of Solvents and Extraction Methods on the Antioxidant Activity of P. niruri

2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Hafizah Mohd Hadzri ◽  
Mohd Azizi Che Yunus ◽  
Salman Zhari ◽  
Fahim Rithwan
Keyword(s):  
Antioxidant Activity ◽  
Extraction Method ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Soxhlet Extraction ◽  
Solvent Polarity ◽  
Extraction Methods ◽  
The Other ◽  
Natural Antioxidant ◽  
Total Phenolic

The effects of different types of solvents and extraction method were investigated to determine the presence of antioxidant contents and activity from the P. niruri plant. The aim of this study is to determine which extraction method will give higher natural antioxidant contents and antioxidant activity. The content of natural antioxidant and antioxidant activity were analysed by total phenolic content (TPC), total flavonoid content (TFC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay. The results showed that extracts from a supercritical fluid extraction (SFE) method without the addition of modifier showed the highest content of total phenolic (187.66 mg GAE/ g) and flavonoid (1100.93 mg QE/g) in P. niruri compared to the other methods of extraction with different type of solvents. The extract of P. niruri from different extraction methods showed antioxidant activity on DPPH radical scavenging assay. The soxhlet extraction method by methanol showed the lowest IC50 compared to the other methods of extraction. The results revealed that P. niruri extracts had different content of antioxidant and antioxidant activity. The solvent polarity and different methods of extraction play significant roles in determining the most suitable method for production of antioxidant contents and antioxidant activity from P. niruri extracts.

Hardness Testing of Vulcanized Rubber. II. Comparisons of Readings of Various Instruments

1944 ◽  
Vol 17 (1) ◽  
pp. 194-199
Author(s):  
H. A. Daynes ◽  
J. R. Scott
Keyword(s):  
The Other ◽  
Hardness Testing ◽  
Hardness Tester ◽  
Vulcanized Rubber

Abstract Tests have been made on numerous rubbers with the R.A.B.R.M. hardness gauge, the Strachan piezomicrometer, and the Pusey and Jones plastometer (using in each case ¼-in. and ⅛-in. diameter balls) and with the Shore durometer and Schopper hardness tester, to determine the relationships between the readings given by these instruments. The results are tabulated and represented graphically as correlation curves. A conversion chart is given by which the reading obtained with any one instrument or size of ball can readily be converted into the corresponding reading for any of the other instruments or sizes of ball.

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