Vulcanization Kinetics of Natural Rubber Coagulated by Microorganisms with Use of a Vulcameter

Abstract

Kinetics of vulcanization of natural rubber coagulated by microorganisms (NR-m) was studied with the use of a vulcameter. In the induction period of vulcanization, the time t0 of NR-m is shorter than that of natural rubber coagulated by acid (NR-a), and the rate constant k1/a of NR-m are greater than that of NR-a. Both the curing periods of NR-m and NR-a consist of two stages. The first stage follows first-order reaction. The rate constants k2 of NR-m in the first stage are greater than that of NR-a at the same temperature, and so are the activation energy E2. The second stage (end stage of the curing period) does not follow first-order reaction, and the calculated reaction order n of NR-m is in the range of 0.82-0.85, and that of NR-a is in the range of 0.64-0.72. The rate constants k3 of the second stage for NR -m are greater than that of NR-a at the same temperature, and so is the activation energy E3.

Vulcanization Kinetics of Starch Xanthate /Natural Rubber Composite

“…Calculation of kinetic parameters. The induction periods of NR and SX/NR composite are expressed the following equation [9,10] ln(M H -M t ) = A -K 1 (t -t 0 ) α…”

Effect of non‐rubber substances on vulcanization kinetics of natural rubber

“…The induction periods of NR and NR E are treated with an empirical equation17, 18, 20 of where M H is the maximum torque; M t is the torque at vulcanization time t , t 0 is the time for minimum torque M L , which just begins to increase; A and k 1 are constants, α is a modified coefficient, and k 1 1/α is used as the rate constant of induction period.…”

“…The microbial coagulation and acid coagulation are commonly used two main methods to coagulate fresh NR latex. Wang et al20 studied the effects of the two coagulation methods on vulcanization kinetics of NR and came to a conclusion that the rate constants of induction period and curing period of NR coagulated by microorganisms are greater than that of NR coagulated by acid.…”

Rheological Behavior of Raw Natural Rubber Coagulated by Microorganisms

“…Natural rubber (NR) latex from Hevea Brasiliensis is a renewable biosynthesis polymer with excellent outstanding resilience, high strength and good processability, etc [1][2][3] . It is composed of about 30-40% rubber hydrocarbon as rubber latex particles and about 6-8% minor non-rubber components such as proteins, mineral salts, carbohydrates, organic acids and lipids dispersed in water [4,5] .…”