Experimental determination of the quantity and distribution of chemical crosslinks in unaged and aged natural rubber, part 1: Peroxide vulcanization

2018 ◽  
Vol 70 ◽  
pp. 263-274 ◽  
Author(s):  
Samantha Howse ◽  
Christopher Porter ◽  
Tesfaldet Mengistu ◽  
Richard J. Pazur
Keyword(s):  
Natural Rubber ◽  
Experimental Determination ◽  
Rubber Part ◽  
Chemical Crosslinks

Structural Characterization of Filled Vulcanizates Part 1. Determination of the Concentration of Chemical Crosslinks in Natural Rubber Vulcanizates Containing High Abrasion Furnace Black

1967 ◽  
Vol 40 (3) ◽  
pp. 866-882 ◽  
Author(s):  
M. Porter
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Volume Fraction ◽  
Exponential Relationship ◽  
Furnace Black ◽  
Simple Linear Relationship ◽  
Chemical Crosslinks ◽  
Natural Rubber Vulcanizates

Abstract The degree to which HAF black restricts the swelling of natural rubber vulcanizates in n-decane has been determined using a vulcanizing system in which the stoichiometry of crosslinking is unaffected by the carbon black. The dependence of the degree of restriction, as measured by the ratio of the volume fractions of rubber in the filled and unfilled vulcanizates swollen to equilibrium, on the concentration of carbon black follows an exponential relationship previously proposed by Lorenz and Parks. This is found to be equivalent to a simple linear relationship between the apparent and actual crosslink concentrations: napparent/nactual=1+Kϕ, where K is a constant characteristic of the filler and φ is its volume fraction in the vulcanizate. The relation has been used to determine actual crosslink concentrations in filled natural rubber vulcanizates. HAF black is found to cause increases of up to 25 per cent in the yield of polymer to polymer crosslinks in conventional sulfur vulcanizing systems, accompanied by changes in rate of cure and of crosslink reversion. All these are small compared with the effect of the filler on many physical properties.

Vulcanization of Elastomers. 46. The Kinetics of Crosslinking

1964 ◽  
Vol 37 (3) ◽  
pp. 698-708 ◽  
Author(s):  
W. Scheele ◽  
K.-H. Hillmer
Keyword(s):  
Natural Rubber ◽  
Experimental Determination ◽  
Present Article ◽  
Reaction Order ◽  
Practical Importance ◽  
Static Modulus ◽  
Working Out ◽  
Kinetics Of

Abstract The present article represents a first contribution to the investigation of the crosslinking kinetics of 1,5-polyenes, with sulfur as the vulcanizing agent. It is principally concerned with working out the pertinent methodology, and hence is a report on our experience with the “Agfa Vulcameter” (also called the Bayer Vulcameter). Using as an example the zinc benzothiazolyl mercaptide (ZnMBT)/zine stearate accelerated vulcanization of natural rubber with sulfur, which in any case runs with practically no reversion at moderate temperatures, and thus permits an experimental determination of the crosslinking end-values, we were able to show that crosslinking can be described quantitatively and qualitatively with the help of an Agfa Vulcameter. It was proved that the same reaction order and the same rates are obtained, as when the static modulus is used as the criterion for crosslinking. The scientific and practical importance of the results are pointed out.

Experimental determination of a state equation for dissipative granular gases

1999 ◽  
Vol 96 (6) ◽  
pp. 1111-1116 ◽  
Author(s):  
E. Falcon ◽  
S. Fauve ◽  
C. Laroche
Keyword(s):  
Experimental Determination ◽  
State Equation ◽  
Granular Gases

AN EXPERIMENTAL DETERMINATION OF ISOLATED BUBBLE ACOUSTICS IN A NUCLEATE BOILING SYSTEM

1974 ◽  
Author(s):  
G. E. Robinson ◽  
Frank W. Schmidt ◽  
H. R. Block ◽  
G. Green
Keyword(s):  
Experimental Determination ◽  
Nucleate Boiling
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