Effect of devulcanization on crosslink density and crosslink distribution of carbon black filled natural rubber vulcanizates (Record no. 57783)

MARC details
000 -LEADER
fixed length control field 02514nam a2200205Ia 4500
100 ## - MAIN ENTRY--AUTHOR NAME
Personal name Joseph A M
245 #0 - TITLE STATEMENT
Title Effect of devulcanization on crosslink density and crosslink distribution of carbon black filled natural rubber vulcanizates
260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT)
Name of publisher Rubber Chemistry and Technology
Year of publication 2016
300 ## - PHYSICAL DESCRIPTION
Number of Pages 653-670
500 ## - GENERAL NOTE
General note Source Year: 2016
520 ## - SUMMARY, ETC.
Summary, etc Carbon black filled natural rubber (NR) vulcanizates were devulcanized at ambient temperature in a two roll mill. The effect of cure system, that is, conventional vulcanization (CV), semiefficient vulcanization (semi EV), and efficient vulcanization (EV) systems, used for vulcanization of the original sample, on the efficiency of devulcanization was studied. The efficiency of devulcanization expressed as percentage devulcanization of the samples calculated from residual crosslink density measurements was correlated with the sol fraction of the devulcanized samples based on Horikx analysis. Using chemical probe analysis, we determined (i) the crosslink distribution pattern of the original sample, (ii) the extent to which the different types of crosslinks-that is, polysulfidic, disulfidic, and monosulfidic crosslinks-have been debonded or broken during the shearing process in the two roll mill, and (iii) the pattern of bond formation during revulcanization. Mechanical shearing predominantly breaks the majority crosslink type (polysulfidic crosslinks in CV and semi EV cure systems and disulfidic crosslinks in EV samples). Irrespective of the significant reduction in total crosslink density in all three sets of samples, chain shortening reactions similar to the post-crosslinking chemical reactions at curing temperatures also occur during mechanical shear at ambient conditions, which increased the absolute value of monosulfidic links in CV and semi EV systems. However, in the devulcanized EV system, the absolute value of polysulfidic crosslinks increased, which might be due to the re-crosslinking of the cleaved bonds. All the devulcanized samples were revulcanized, and the mechanical and morphological properties were analyzed. The percentage retention of the vulcanizate properties after revulcanization of the devulcanized samples correlated vry well with efficiency of devulcanization.
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical Term Carbon black
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical Term Crosslink density
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical Term Devulcanization
700 ## - ADDED ENTRY--PERSONAL NAME
Personal name Alex R
700 ## - ADDED ENTRY--PERSONAL NAME
Personal name George B
700 ## - ADDED ENTRY--PERSONAL NAME
Personal name Madhusoodanan K N
942 ## - ADDED ENTRY ELEMENTS (KOHA)
Koha item type Journals
Holdings
Withdrawn status Lost status Damaged status Not for loan Home library Current library Shelving location Date acquired Serial Enumeration / chronology Koha item type
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