scholarly journals FLOCCULATION, REINFORCEMENT, AND GLASS TRANSITION EFFECTS IN SILICA-FILLED STYRENE-BUTADIENE RUBBER

2011 ◽  
Vol 84 (4) ◽  
pp. 507-519 ◽  
Author(s):  
C. G. Robertson ◽  
C. J. Lin ◽  
R. B. Bogoslovov ◽  
M. Rackaitis ◽  
P. Sadhukhan ◽  
...  

Abstract The introduction of silanes to improve processability and properties of silica-reinforced rubber compounds is critical to the successful commercial use of silica as a filler in tires and other applications. The use of silanes to promote polymer–filler interactions is expected to limit the development of a percolated filler network and may also affect the mobility of polymer chains near the particles. Styrene-butadiene rubber (SBR) was reinforced with silica particles at a filler volume fraction of 0.19, and various levels of filler–filler shielding agent (n-octyltriethoxysilane) and polymer–filler coupling agent (3-mercaptopropyltrimethoxysilane) were incorporated. Both types of silane inhibited the filler flocculation process during annealing the uncured rubber materials, thus reducing the magnitude of the Payne effect. In contrast to the significant reinforcement effects noted in the strain-dependent shear modulus, the bulk modulus from hydrostatic compression was largely unaltered by the silanes. Addition of polymer–filler linkages using the coupling agent yielded bound rubber values up to 71%; however, this bound rubber exhibited glass transition behavior which was similar to the bulk SBR response, as determined by calorimetry and viscoelastic testing. Modifying the polymer–filler interface had a strong effect on the nature of the filler network, but it had very little influence on the segmental dynamics of polymer chains proximate to filler particles.

2012 ◽  
Vol 19 (01) ◽  
pp. 1250003
Author(s):  
JIAN CHEN ◽  
YONGZHONG JIN ◽  
JINGYU ZHANG ◽  
YAFENG WU ◽  
CHUNCAI MENG

Bound rubber in carbon black (CB) filled rubber (natural rubber (NR) and styrene–butadiene rubber (SBS)) was prepared by the solvent method. The nanomorphology of CB and rubber/CB soluble rubber was observed by atomic force microscope. The results show that high-structure CB DZ13 has a "grape cluster" structure which consists of many original particles with the grain size of about 30–50 nm. Graphitizing process of CB decreases the amount of bound rubber. The NR/DZ13 soluble rubber with island–rim structure has been obtained, where the islands are DZ13 particles and the rims around the islands are occupied by NR film. But when the graphitized DZ13 particles were used as fillers of rubber, we have only observed that some graphitized DZ13 particles were deposited on the surface of the globular-like NR molecular chains, instead of the spreading of NR molecular chains along the surface of DZ13 particles, indicating that graphitized DZ13 has lower chemical activity than ungraphitized DZ13. Especially, we have already observed an interesting unusual bound rubber phenomenon, the blocked "bracelet" structure with the diameter of about 600 nm in which CB particles were blocked in ring-shaped SBS monomer.


2018 ◽  
Vol 91 (2) ◽  
pp. 453-468 ◽  
Author(s):  
Hong-Yuan Ren ◽  
Zheng Sun ◽  
Li-Qun Zhang ◽  
You-Ping Wu ◽  
Qiang Huang ◽  
...  

ABSTRACT Two silane coupling agents, bis-(γ-triethoxysilylpropyl)-tetrasulfide (Si69) and vinyltriethoxysilane (A151), were selected to investigate their effects on structure and properties of silica-filled methyl vinyl silicone rubber (VMQ)/emulsion styrene butadiene rubber (ESBR) composites. The filler–rubber interactions were investigated via bound rubber content and solid-state 1H low-field nuclear magnetic resonance (NMR) spectroscopy, and the mass ratio of VMQ and ESBR in the rubber–filler gel was investigated by thermogravimetric analysis (TGA). The results revealed that VMQ showed a better compatibility with silica than ESBR. Compared with the A151 composite, the composite with Si69 showed the higher content of ESBR in rubber–filler gel, which resulted in the higher bound rubber content and the weaker Payne effect, and it also exhibited higher tensile strength, higher tear strength, better wear resistance, and lower hardness. However, the presence of Si69 reduced the crosslink efficiency of ESBR and completely inhibited the crosslinking of VMQ, which caused the composite to show higher tan δ value at 60 °C than the A151 composite.


2019 ◽  
pp. 000-000
Author(s):  
Qing-Yuan Han ◽  
Xu Li ◽  
Yu-Chun Li ◽  
You-Ping Wu

ABSTRACT The compatibility between solution polymerized styrene–butadiene rubber (SSBR 2466) and natural rubber (NR) is characterized by differential scanning calorimetry and dynamic mechanical thermal analysis. The single glass transition in the entire temperature range of all NR/SSBR blends and good correlation between Tg and SSBR fraction prove the excellent compatibility between SSBR 2466 and NR. With increasing SSBR content, a reduced Payne effect, more homogeneous dispersion of silica, stronger rubber–filler interaction, and more silica selectively distributed in the SSBR phase were determined via rubber-processing analysis, transmission electron microscopy, bound rubber, and thermogravimetric analysis, respectively. The high vinyl content, low styrene content, and end-functionalized structure of SSBR play vital roles in promoting its compatibility with NR and a stronger rubber–silica linkage. The resulting increased tan δ at 0 °C and low tan δ at 60 °C indicates good wet-skid resistance and low rolling resistance by blending SSBR 2466, and 70/30 NR/SSBR is the best balance for producing a “green tire” tread.


2003 ◽  
Vol 76 (2) ◽  
pp. 299-317 ◽  
Author(s):  
A. M. Shanmugharaj ◽  
Anil K. Bhowmick

Abstract Rheometric and mechanical properties, hysteresis and swelling behavior of the Styrene-Butadiene Rubber vulcanizates (SBR) filled with unmodified and novel electron beam modified surface treated dual phase fillers were investigated. Scorch time increases for these modified filler loaded vulcanizates due to introduction of quinone type oxygen on the surface. Electron beam modification of dual phase filler in the absence of trimethylol propanetriacrylate (TMPTA) or triethoxysilylpropyltetrasulphide (Si-69) significantly improves the modulus of the SBR vulcanizates, whereas the values of tensile strength and elongation at break drop. However, presence of TMPTA or silane slightly increases the modulus with significant improvement in tensile strength. This effect is more pronounced at higher loading of these modified fillers in SBR vulcanizates. These variations in modulus and tensile strength are explained by the equilibrium swelling data, Kraus plot and a new mathematical model interpreting the polymer-filler interaction. Hysteresis loss ratio of SBR vulcanizates loaded with irradiated fillers in absence and presence of TMPTA or silane increases due to highly aggregated structure of the filler.


2012 ◽  
Vol 430-432 ◽  
pp. 1076-1080
Author(s):  
Mei Chun Li ◽  
Xin Ge ◽  
Jong Hyuk Lim ◽  
Min Su Kim ◽  
Ur Ryong Cho

Starch/Styrene Butadiene Rubber (SBR) biocomposites were prepared by directly blending of starch and SBR on a two-roll miller. Two types of starch: pure starch and modified starch (M-starch) were used as rubber fillers. M-starch were synthesized by grafting of methyl methacrylate (MMA) monomer onto starch backbone using ceric ammonium nitrate-initiated radical polymerization. Coupling agent styrene-g-(maleic anhydride) (SMA) was used to further improve the interfacial interaction between the filler and rubber matrix. The morphology and mechanical properties of unmodified starch/SBR and M-starch/SBR biocomposites with SMA content of 0, 1, 3, and 5 phr were investigated. SEM observations showed the particle size of M-starch decreased and their dispersion in the SBR matrix significantly improved than unmodified starch. Mechanical properties of M-starch/SBR biocomposites were superior than those of unmodified starch/SBR biocomposites.


Sign in / Sign up

Export Citation Format

Share Document