Processing Characteristics of Synthetic Tire Rubber

1943 ◽  
Vol 16 (1) ◽  
pp. 203-208
Author(s):  
B. S. Garvey ◽  
M. H. Whitlock ◽  
J. A. Freese
Keyword(s):  
Natural Rubber ◽  
Laboratory Tests ◽  
Laboratory Methods ◽  
Tire Rubber ◽  
Synthetic Rubber ◽  
Different Types ◽  
Full Production ◽  
The Government ◽  
Processing Properties ◽  
Made In

Abstract The processing characteristics of synthetic tire rubber, such as is being made in the government program, are sufficiently different from those of natural rubber to require different laboratory and factory treatment. Since the laboratory tests used for the evaluation of processing characteristics were developed for natural rubber, it is not surprising that they are not so satisfactory for synthetic rubber. The purpose of this paper is to discuss some of the characteristics of synthetic tire rubber, and to describe certain tests which have been found useful for evaluating different types of synthetic rubber or different compounds of the same synthetic rubber. In the course of the development, it has been necessary to evaluate rubbers with a wide variety of processing properties. As production has increased, there has been less variation in the output from any one plant. As the newer and larger plants come into full production, we can expect greater uniformity from each plant and between different plants. We can also look forward to gradual improvements in processing characteristics. This development will be ensured by adequate laboratory methods for evaluating processing properties. This discussion is based in part on variations encountered in development work and in part on the properties of the present production from one plant.

Recent Developments in Synthetic Rubber Latex

1961 ◽  
Vol 34 (5) ◽  
pp. 1501-1520 ◽  
Author(s):  
L. H. Howland ◽  
R. W. Brown
Keyword(s):  
Amino Groups ◽  
Rubber Latex ◽  
Low Viscosity ◽  
Polar Groups ◽  
Synthetic Rubber ◽  
Polymerization System ◽  
Recent Developments ◽  
The Government ◽  
Solids Content ◽  
Made In

Abstract Progress has proceeded at a good rate since the close of the Government Program in the spring of 1955. Improved latexes have been made, and the technology of manufacture and of application has advanced. Also progress has been made in fundamental latex research. Some of the newer latexes representing the more important advances are those involving functonal groups derived from the use of unsaturated monomers such as those containing amino groups and carboxy groups in the polymerization system, those from solid rubbers by the solvent emulsion technique, and those of higher solids content including the agglomerated latexes giving 68 per cent minimum solids at low viscosity. Some of the applications of greatest growth are : 1. Carpet backing involving both sulfur curing and so-called self-curing (noncured) elastomer latexes. The latter obtain strength from polar groups including functional (carboxyl) groups and/or fairly high styrene content. 2. Foam sponge backed carpets. In 1954 it was suggested that synthetic rubber latexes would have a permanent place in our economy. This has now come to pass, and natural latex is decreasing in volume compared to total synthetic rubber latex consumption. It now appears that by forming a latex from cis polyisoprene (synthetic natural rubber) and adding it to our list of latexes, that our country could probably become independent of the natural product.

Lignin as a Compounding Ingredient for Natural Rubber

1957 ◽  
Vol 30 (2) ◽  
pp. 639-651 ◽  
Author(s):  
I. Sagajllo
Keyword(s):  
Natural Rubber ◽  
High Resistance ◽  
Pilot Plant ◽  
Test Results ◽  
Dry Powder ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
Pilot Plant Scale ◽  
Made In ◽  
Natural And Synthetic

Abstract Important claims have been made in recent years regarding the capacity of lignin to reinforce natural and synthetic rubber. In 1949 Dawson reviewed the literature on the use of lignin in rubber and drew particular attention to the work of Keilen and Pollak who had shown that in certain circumstances lignin could be considered to rival EPC black in its ability to yield strong GR-S vulcanizates with high resistance to tear. Raff and his coworkers subsequently showed that the reinforcement of GR-S by lignin is enhanced if the lignin, before coprecipitation with the latex, is subjected to oxidation; other workers studied the application of lignin to the reinforcement of different elastomers, the influence of coprecipitation conditions on the properties of the product, and the problem of overcoming the delaying effect of lignin on vulcanization of lignin-natural rubber coprecipitates. Keilen and Pollak in their experiments incorporated lignin into rubber by coprecipitation at the latex stage, but they indicated that similar results could be obtained if lignin “in the gelled state” was added to rubber by milling. No reinforcement was observed however when lignin was added to rubber as a dry powder. Lignin is potentially an abundant and cheap material which according to the above claims should extend the range of useful compounds available to rubber manufacturers. The present paper describes work undertaken to gain firsthand knowledge of the technique of coprecipitating lignin with natural rubber from preserved latex, to learn something about the properties of natural rubber compounds prepared from lignin coprecipitates, and to study possible ways of incorporating lignin into rubber by means other than coprecipitation. It also records test results for masterbatches prepared by the Rubber Research Institute of Malaya from fresh latex on a pilot plant scale.

Measurement of Refractive Index of Elastomers

1952 ◽  
Vol 25 (3) ◽  
pp. 693-699 ◽  
Author(s):  
Aurelia Arnold ◽  
Irving Madorsky ◽  
Lawrence A. Wood
Keyword(s):  
Refractive Index ◽  
Standard Deviation ◽  
Natural Rubber ◽  
Light Source ◽  
Transition Temperatures ◽  
Incandescent Light ◽  
Synthetic Rubber ◽  
Second Order Transition ◽  
The Government

Abstract The measurement of the refractive index of elastomers is discussed, with particular reference to GR-S rubber and the use of an Abbé type of refractometer. Detailed descriptions of the apparatus used and the procedure for GR-S rubber are given. Common sources of error are discussed and methods of minimizing these errors are given. A detailed stady has been made of the precision obtainable with GR-S polymers using the Abbé type of refractometer with an incandescent light source. It was found that the standard deviation corresponding to variability of a single random determination was 0.00007. The method has been used for several years as the basis for the determination of bound styrene in copolymers of butadiene and styrene, and is currently employed for control purposes in the government-owned synthetic rubber plants. It has also been used for determining the percentage of rubber hydrocarbon in natural rubber and for locating second-order transition temperatures.

The Second Mile

1943 ◽  
Vol 16 (4) ◽  
pp. 713-745
Author(s):  
L. B. Sebrell
Keyword(s):  
Comparative Study ◽  
Natural Rubber ◽  
Present Status ◽  
Butyl Rubber ◽  
Probable Structure ◽  
Synthetic Rubber ◽  
Accurate Picture ◽  
The Government ◽  
The Comparative Study ◽  
Styrene Butadiene

Abstract The title “The Second Mile” was inspired by an address given by W. E. Wickenden, of the Case School of Applied Science, on an entirely different subject. Since this title seemed to suit the synthetic rubber situation as it now exists, Wickenden's permission was secured to use the title in connection with this lecture. In its broader aspects, the paper purports to cover the present status of the synthetic rubber situation. Natural rubber will be compared with the copolymers made from butadiene and styrene, butadiene and acrylonitrile, and the copolymers generally known as Butyl rubber. These three materials were chosen for the comparative study because they are the materials which the Government proposes to use in the largest quantities to alleviate the present shortage of rubber. It is hoped that the data will give a fairly accurate picture of the comparative or relative values of these synthetic rubbers and natural rubber. There will be no discussion of the methods of manufacture, which are still more or less secret. It is proposed also to go into the probable structure of these polymers and to indicate some trends of research which might profitably be followed to improve them.

Carbon Blacks in GR-S

1946 ◽  
Vol 19 (1) ◽  
pp. 100-122 ◽  
Author(s):  
D. Parkinson
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Carbon Blacks ◽  
Styrene Copolymer ◽  
Synthetic Rubber ◽  
First Approximation ◽  
Different Types ◽  
Almost All ◽  
Butadiene Styrene

Abstract The importance of different types of colloidal carbon as reinforcing agents for the butadiene-styrene copolymer, GR-S, has been stressed in recent papers. It has been shown that, to a first approximation, the effect of carbon blacks in this type of synthetic rubber is similar to that in natural rubber, but it has been shown also that the extremely low tensile strength and poor tearing properties of uncompounded vulcanized GR-S necessitates the addition of some form of carbon black to almost all types of compounds. The present paper considers the influence of carbon blacks in vulcanized GR-S compounds. Earlier papers have discussed the effect of carbon blacks in natural rubber.

Noise properties of thin-film Ni-P resistors embedded in printed circuit boards

2013 ◽  
Vol 61 (3) ◽  
pp. 731-735
Author(s):  
A.W. Stadler ◽  
Z. Zawiślak ◽  
W. Stęplewski ◽  
A. Dziedzic
Keyword(s):  
Thin Film ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Noise Component ◽  
Printed Circuit ◽  
Resistance Bridge ◽  
Different Types ◽  
Signal Path ◽  
Resistance Fluctuations ◽  
Made In

Abstract. Noise studies of planar thin-film Ni-P resistors made in/on Printed Circuit Boards, both covered with two different types of cladding or uncladded have been described. The resistors have been made of the resistive-conductive-material (Ohmega-Ply©) of 100 Ώ/sq. Noise of the selected pairs of samples has been measured in the DC resistance bridge with a transformer as the first stage in a signal path. 1/f noise caused by resistance fluctuations has been found to be the main noise component. Parameters describing noise properties of the resistors have been calculated and then compared with the parameters of other previously studied thin- and thick-film resistive materials.

Up-flow roughing filtration: rehabilitation of a water treatment plant in Tarata, Bolivia

1998 ◽  
Vol 37 (9) ◽  
pp. 105-112 ◽  
Author(s):  
Ana María Ingallinella ◽  
Luis María Stecca ◽  
Martin Wegelin
Keyword(s):  
Water Treatment ◽  
Pilot Plant ◽  
Laboratory Tests ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Horizontal Flow ◽  
Design Parameters ◽  
Sand Filters ◽  
Chemical Products ◽  
Made In

This paper presents the methodology used for the rehabilitation of the pretreatment stage in a water treatment plant for a village located in Bolivia which has 3500 inhabitants. The treatment plant was initially composed by horizontal-flow roughing filters and slow sand filters, but due to the high contents of colloidal turbidity of the providing source, it did not work properly. A plan of rehabilitation was made which comprised laboratory tests, pilot tests and proposal of modifications based on the results of previous stages. The laboratory tests were made in order to find the optimum conditions to coagulate the raw water. It was found that horizontal-flow roughing filters must be turned into up-flow roughing filters, so a pilot plant was built and was operated for three months in order to find suitable design parameters. The results obtained obtained during the operation of the pilot plant and the proposal of modifications are presented. The results of operation of the final plant, which are also reported, demonstrated the advantages of the up-flow roughing filtration as a pretreatment stage when it is necessary to add chemical products in small treatment plants.

RURAL TOURISM IN INDIA CHALLENGES AND OPPORTUNITIES

2018 ◽  
Vol 6 (26) ◽  
Author(s):  
Pankaj Sharma ◽  
Ravi Parkash
Keyword(s):  
Private Sector ◽  
Rural Areas ◽  
Economic Condition ◽  
Rural Tourism ◽  
Rural Location ◽  
Different Types ◽  
Challenges And Opportunities ◽  
Political Background ◽  
The Government

The paper analyze the role of rural tourism for the development of rural areas, The study analyzed how the different types of tourist product diversifications influence the development possibilities of studied rural areas in India. The government should sponsor private Sector to promote tourism in rural areas. For upgrading the rural tourism government requires to understand the rural location, demography, socio-culture, financial and political background of that area. How we can involve the rural citizens to improve their socio-economic condition. The objective of this paper is to present an update on rural tourism expansion and development in India. Rural tourism is rising in terms of number of visitors and the government of India should focus on it as an engine of growth

scholarly journals Downregulation of exosomal let-7d and miR-16 in idiopathic pulmonary fibrosis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Donato Lacedonia ◽  
Giulia Scioscia ◽  
Piera Soccio ◽  
Massimo Conese ◽  
Lucia Catucci ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Therapy Response ◽  
Down Regulation ◽  
Cross Sectional ◽  
Exosomal Mirnas ◽  
Different Types ◽  
Sectional Analysis ◽  
Made In

Abstract Background Idiopathic Pulmonary Fibrosis (IPF) is a degenerative interstitial lung disease with both a poor prognosis and quality of life once the diagnosis is made. In the last decade many features of the disease have been investigated to better understand the pathological steps that lead to the onset of the disease and, moreover, different types of biomarkers have been tested to find valid diagnostic, prognostic and therapy response predictive ones. In the complexity of IPF, microRNA (miRNAs) biomarker investigation seems to be promising. Methods We analysed the expression of five exosomal miRNAs supposed to have a role in the pathogenesis of the disease from serum of a group of IPF patients (n = 61) and we compared it with the expression of the same miRNAs in a group of healthy controls (n = 15). Results In the current study what emerged is let-7d down-regulation and, unexpectedly, miR-16 significant down-regulation. Moreover, through a cross-sectional analysis, a clustering of the expression of miR-16, miR-21 and miR-26a was found. Conclusions These findings could help the individuation of previously unknown key players in the pathophysiology of IPF and, most interestingly, more specific targets for the development of effective medications.

scholarly journals Modified Nanoclays/Straw Fillers as Functional Additives of Natural Rubber Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec
Keyword(s):  
Natural Rubber ◽  
Raw Materials ◽  
Research Work ◽  
Damping Properties ◽  
Main Research ◽  
Functional Additives ◽  
Different Types ◽  
Elastomeric Materials ◽  
Research Goal ◽  
The Impact

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.

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