Chemical tests for raw and vulcanized rubber. Butadiene rubber

1994 ◽  
2018 ◽  
Vol 51 (6) ◽  
pp. 493-511
Author(s):  
Fabián E Hernández ◽  
C Medina ◽  
G Moraga ◽  
J Ramírez ◽  
AF Jaramillo ◽  
...  

The purpose of this work was to correlate the effects of thermal aging on the macroscopic properties and microstructural changes for three vulcanized rubber types. The materials were subjected to accelerated thermal aging for periods between 0 and 168 h at 100°C. This aging was evaluated by investigating the mechanical properties and by Fourier transform infrared (FTIR) and Raman analysis. The results showed that subjecting the materials to thermal aging for a longer time decreased the elongation at break and tear strength and increased the hardness, while tensile strength exhibited different behavior and followed a different trend. The spectroscopy analyses indicated that there is a decrease in the amount of C=C present in the polymer as the aging time increased, which could be identified by the decrease in peak intensity at 1537 and 1600 cm−1 in the FTIR and Raman spectrum, respectively. These results were attributed mainly to an increase in cross-link density, which caused degradation of the material, essentially by a loss of ductility. A good linear relation ( R2 approximately 0.95) between changes in the intensity of FTIR peaks for the C=C signal and changes in elongation at break and hardness was found, concluding that these are good indicators of degradation in elastomers.


2016 ◽  
Vol 717 ◽  
pp. 57-61
Author(s):  
Wei Liu ◽  
Zhong Cun Bao ◽  
Cheng Zhong Zong

Flexible fatigue properties is an important property of rubber, it can reflect the service life of rubber products. Different types of SSBR were used in the vulcanized rubber with NR contributed different to the flexible fatigue properties. In this paper, 5 different types of SSBR with special structure were used to study the mechanical properties, thermal properties and the flexible fatigue properties. In a result, with different types SSBR, the vulcanized rubber show different basic mechanical properties and flexible fatigue properties, but little effect to the hardness and stretching stress. Above all these SSBR, RC2564S is the best which contribute to flexible fatigue properties.


2002 ◽  
Vol 75 (5) ◽  
pp. 955-968 ◽  
Author(s):  
Jeremy E. Morin ◽  
Drew E. Williams ◽  
Richard J. Farris

Abstract High-pressure high-temperature sintering (HPHTS) is a novel recycling technique that makes it possible to recycle vulcanized rubber powders made from waste rubber (namely scrap tires) through only the application of heat and pressure. A brief look into the mechanism of sintering will be presented along with information about the influence of molding variables, such as time, temperature, pressure and rubber particle size on the mechanical properties of the produced parts. One of the most interesting observations is that powders of every crosslinked elastomer attempted sintered together via this technique, including silicone rubber (SI), sulfur cured [natural rubber (NR), ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber (SBR)], peroxide cured butadiene rubber (BR), and fluoroelastomers (FKM). Early work on sintered rubber made from commercially available rubber powder had a modulus of 1 to 2 MPa, strength of 4 to 7 MPa and an elongation at break of 150–250%. Recently, in-house ground samples of SBR have had sintered values over 9.5 MPa strength and 275% elongation, or greater than 60% retention of the original properties. Many of these mechanical properties are comparable with industrially manufactured rubbers, and it is believed that recycled rubbers produced via HPHTS offer the potential to replace virgin rubber in numerous applications.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1091 ◽  
Author(s):  
Mariusz Siciński ◽  
Ewa Korzeniewska ◽  
Mariusz Tomczyk ◽  
Ryszard Pawlak ◽  
Dariusz Bieliński ◽  
...  

This paper describes a method of laser ablation for improving the hydrophobic properties of vulcanized rubber. The treatment was tested on acrylonitrile rubber (NBR) and styrene butadiene rubber (SBR) containing carbon nanotubes and soot as fillers. The surface layer of the vulcanizates was modified using a nanosecond-pulsed laser at 1060 nm wavelength. The parameters of the ablation process were congruent, so no chemical changes in the polymeric material were observed. Evaluation of the surface condition of the laser-textured samples was performed using a Leica MZ6 stereoscopic microscope, operating with MultiScan 8.0 image analysis software. The contact angles were determined for all the samples before and after the surface modification process. Following modification of the surface morphology, with the best parameters of laser ablation, the contact angle increased, reaching 147°, which is very close to the threshold of superhydrophobicity (150°). On the basis of the results from several tests, laser ablation with a fiber-pulsed laser can be considered a very useful method for producing rubbers with superhydrophobic surfaces.


2013 ◽  
Vol 750-752 ◽  
pp. 1109-1112
Author(s):  
Ya He Hou ◽  
Xiao Ping Zhang

The gadolinium acrylate Gd (AA)3/hydrogenated nitrile-butadiene rubber (HNBR) composites have been prepared by in-situ reaction with dicumyl peroxide (DCP) as vulcanizing agent. The original morphology of Gd (AA)3 and its dispersion state in un-vulcanized and vulcanized rubber compound have been analyzed by scanning electron microscopy (SEM). The results demonstrated that Gd (AA)3 dispersed uniform in the composite with smaller size and better interface bonding because of the in-situ reaction. The mechanical properties of Gd (AA)3/HNBR reached the best when filled with 40 phr Gd (AA)3 and the X-ray shielding property increased with the increasing filling amount of Gd (AA)3.


1970 ◽  
Vol 43 (6) ◽  
pp. 1349-1358 ◽  
Author(s):  
B. G. Corman ◽  
M. L. Deviney ◽  
L. E. Whittington

Abstract Migration of oils, curatives, antioxidants, and other compounding materials in a vulcanized rubber matrix is a general phenomenon. A continuing, long range program has been undertaken in these laboratories to understand better this effect, in order that ultimately the compounder can predict, from a knowledge of the molecular nature of the penetrant and the physico-chemical properties of the cured matrix, the distribution of the various components during the service life of the finished rubber product. A sensitive radiotracer approach with earbon—14 is being used to study this system. Earlier work in this program has established the general value of the diffusion coefficient for whole paraffinic oils and for aromatic oils and their fractions. In general, this has shown that moderate variations in the molecular composition of the aromatic portions of the oils have only minor effects on these migration rates. Using similar computer derived diffusion coefficients, the current data indicate that naphthenic molecules migrate at equal to slightly higher rates than aromatic molecules of similar boiling points. Thermal diffusion as a mode of separation of the oil gives fractions showing more selectivity (larger differences in migration rates) than the formerly used silica gel procedures. Variations in carbon black type and loading levels have no detectable effect on migration. The most important factor in diffusion is the polymer matrix, which for the oils studied is in the order : polybutadiene (D≃6.4×10−7 cm2 sec−1 at 100° C), natural rubber (D≃3.5×10−7 cm2 sec−1), ethylene-propylene-diene rubber (D≃2.6×10−7 cm2 sec−1) and styrene—butadiene rubber (D≃1.9×10−7 cm2 sec−1). Activation energies for the diffusion process were PBR, 3.1 ; NR, 7.8; EPDM, 10.3; and SBR, 9.9 (energies in kilocalories per mole).


2017 ◽  
Vol 872 ◽  
pp. 160-164
Author(s):  
Xiang Xu Li ◽  
Ur Ryong Cho

Styrene-Butadiene Rubber (SBR) composites incorporated with different fillers with similar filling ratio, were fabricated by latex compounding method. The particle size, tensile strength, abrasion resistance of the vulcanized rubber composites were investigated. The sulfonated bamboo charcoal-chitosan hybrid (sBC-CS) showed great dispersion rate and smaller particle size compared with those of other fillers. In addition, this composite exhibited the best mechanical reinforcing performance among the four fillers.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1626
Author(s):  
Abdullah Gunaydin ◽  
Clément Mugemana ◽  
Patrick Grysan ◽  
Carlos Eloy Federico ◽  
Reiner Dieden ◽  
...  

A set of poly(isobornyl methacrylate)s (PIBOMA) having molar mass in the range of 26,000–283,000 g mol−1 was prepared either via RAFT process or using free radical polymerization. These linear polymers demonstrated high glass transition temperatures (Tg up to 201 °C) and thermal stability (Tonset up to 230 °C). They were further applied as reinforcing agents in the preparation of the vulcanized rubber compositions based on poly(styrene butadiene rubber) (SBR). The influence of the PIBOMA content and molar mass on the cure characteristics, rheological and mechanical properties of rubber compounds were studied in detail. Moving die rheometry revealed that all rubber compounds filled with PIBOMA demonstrated higher torque increase values ΔS in comparison with rubber compositions without filler, independent of PIBOMA content or molar mass, thus confirming its reinforcing effect. Reinforcement via PIBOMA addition was also observed for vulcanized rubbers in the viscoelastic region and the rubbery plateau, i.e. from −20 to 180 °C, by dynamic mechanical thermal analysis. Notably, while at temperatures above ~125 °C, ultra-high-molecular-weight polyethylene (UHMWPE) rapidly loses its ability to provide reinforcement due to softening/melting, all PIBOMA resins maintained their ability to reinforce rubber matrix up to 180 °C. For rubber compositions containing 20 phr of PIBOMA, both tensile strength and elongation at break decreased with increasing PIBOMA molecular weight. In summary, PIBOMA, with its outstanding high Tg among known poly(methacrylates), may be used in the preparation of advanced high-stiffness rubber compositions, where it provides reinforcement above 120 °C and gives properties appropriate for a range of applications.


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