Influence of Chemical Modifications on the Oxidizability of Natural Rubber

1963 ◽  
Vol 2 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Jacqueline de Merlier ◽  
Jean le Bras
Keyword(s):  
Natural Rubber ◽  
Chemical Modifications

Crystallization in Natural Rubber. V. Chemically Modified Rubber

1958 ◽  
Vol 31 (3) ◽  
pp. 519-525
Author(s):  
A. N. Gent
Keyword(s):  
Natural Rubber ◽  
Crystallization Process ◽  
Solid Phase ◽  
Quantitative Agreement ◽  
General Interest ◽  
Chemical Modifications ◽  
Chemically Modified ◽  
Chemical Combination ◽  
Final Extent ◽  
Thiol Acid

Abstract Small amounts of crosslinking have been shown to reduce the rate of crystallization of natural rubber by large factors. It has also been inferred from measurements on peroxide and sulfur vulcanizates of various kinds that sulfur combined in forms other than crosslinks may retard the crystallization process efficiently. A simple banned volume mechanism has been proposed to account for the influence of crosslinking and sidegroup combination on the rate and final extent of crystallization, and has been shown to predict the form of the observed dependences for crosslinked rubber, and approximately the relative magnitudes, but good quantitative agreement was not obtained. Measurements are described below of the rate and final extent of crystallization in natural rubber which has been modified by the chemical combination of sidegroups to the rubber molecule. It has not proved possible to account quantitatively for the observed rates of crystallization, but it is thought that a description of the extremely large effects found to accompany slight chemical modifications will be of general interest. The preparation of the modified rubbers is described elsewhere. The substances added were six thiol acids; namely, monochlorothiolacetic, trichlorothiolacetic, thiolbenzoic, 1-thiolnaphthoic, thiolsalicylic, and thiol-stearic acids. The reactions were carried out in the solid phase by addition of the thiol acid to purified rubber on an open mill, in solution by addition of the thiol acid to a solution of purified rubber in benzene, and in the latex phase.

Chemical modifications of liquid natural rubber

2016 ◽  
Author(s):  
Nur Hanis Adila Azhar ◽  
Hamizah Md Rasid ◽  
Siti Fairus M. Yusoff
Keyword(s):  
Natural Rubber ◽  
Chemical Modifications ◽  
Liquid Natural Rubber

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

Novel Approaches of Using of Spirulina Platensis in Natural Rubber Based Composites

2018 ◽  
Vol 6 (7) ◽  
pp. 680-687
Author(s):  
Ewa Głowińska ◽  
Janusz Datta ◽  
Paulina Parcheta and Natalia Kaźmierczak
Keyword(s):  
Natural Rubber ◽  
Spirulina Platensis ◽  
Novel Approaches
Sign in / Sign up

Export Citation Format

Share Document