THERMAL AGING PROPERTIES AND MOLECULAR TRANSPORT OF SOLVENTS THROUGH VULCANIZATES PREPARED FROM THIOGLYCOLLIC ACID MODIFIED EPOXIDIZED LOW MOLECULAR WEIGHT NATURAL RUBBER BLENDS FILLED WITH ADMIXTURES OF CARBON BLACK AND CARBONIZED RUBBER SEED SHELL

2007 ◽  
Vol 194 (1) ◽  
pp. 1-18 ◽  
Author(s):  
A. K. Akinlabi ◽  
F. E. Okieimen ◽  
U. N. Okwu ◽  
N. A. Oladoja
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Natural Rubber ◽  
Thermal Aging ◽  
Molecular Transport ◽  
Low Molecular Weight ◽  
Rubber Seed ◽  
Rubber Blends ◽  
Thioglycollic Acid ◽  
Aging Properties

Ozonolytic Degradation of Interpolymers of Natural Rubber with Methyl Methacrylate and Styrene

1958 ◽  
Vol 31 (1) ◽  
pp. 82-85
Author(s):  
D. Barnard
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Natural Rubber ◽  
Accurate Determination ◽  
Synthetic Polymers ◽  
Polymer Chains ◽  
Low Molecular Weight ◽  
Rubber Content ◽  
Tert Butyl Hydroperoxide

Abstract The preparation of graft and block interpolymers of natural rubber and synthetic polymers has made it desirable that the number and size of polymer chains attached to rubber be readily determinate. The degradation of unsaturated polymers with tert-butyl hydroperoxide in the presence of osmium tet oxide has been used for the determination of free polystyrene in SBR and carbon black in several elastomers, and has recently been applied to the present problem. The accurate determination of the rubber content of interpolymers by quantitative ozonolysis essentially according to the method of Boer and Kooyman suggested that this might be made the basis of isolation of the attached polymer, the rubber being degraded into fragments of low molecular weight, from which the polymer could be separated by conventional techniques. The method should be applicable to any interpolymer, or mixture, of a polyunsaturated and a saturated polymer and is illustrated with reference to interpolymers of natural rubber (NR)-polymethyl methacrylate (PMM) and NR-polystyrene (PS).

COMPARATIVE PROPERTIES OF SILICA- AND CARBON BLACK-REINFORCED NATURAL RUBBER IN THE PRESENCE OF EPOXIDIZED LOW MOLECULAR WEIGHT POLYMER

2014 ◽  
Vol 87 (2) ◽  
pp. 320-339 ◽  
Author(s):  
P. Saramolee ◽  
K. Sahakaro ◽  
N. Lopattananon ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Carbon Black ◽  
Natural Rubber ◽  
Periodic Acid ◽  
Dynamic Mechanical Properties ◽  
Low Molecular Weight ◽  
Molecular Weight Polymer ◽  
Dynamic Mechanical ◽  
Chemical Structures

ABSTRACT This work investigates the effect of epoxidized low molecular weight natural rubber (ELMWNR) in silica- and carbon black-filled natural rubber (NR) compounds on processing and mechanical and dynamic mechanical properties. The ELMWNRs with different mol% epoxide content were prepared from depolymerization of epoxidized NR using periodic acid in latex state to have a molecular weight in a range of 50 000–60 000 g/mol. Their chemical structures and actual mol% of epoxide were analyzed by 1H NMR. The ELMWNRs were added to the filled NR compounds as compatibilizers at varying loadings from 0 to 15 phr. The addition of ELMWNR decreases compound viscosity and the Payne effect, that is, filler–filler interaction, of the silica-filled compound. In the silica–silane compound and the compound with 28 mol% epoxide (ELMWNR-28), the compound viscosities are comparable. The optimal mechanical properties of silica-filled vulcanizates are obtained at the ELMWNR-28 loading of 10 phr. In contrast, the addition of ELMWNR to a carbon black-filled compound shows only a plasticizing effect. The incorporation of ELMWNR into NR compounds introduces a second glass transition temperature and affects their dynamic mechanical properties. Higher epoxide contents lead to higher loss tangent values of the rubber vulcanizates in the range of the normal service temperature of a tire.

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