Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Silica-filled rubbers

Fine silica network is visible in the in situ silica-filled rubber composite synthesized from 50 wt% of TEOS, producing almost 15 wt% of sdica. On the other hand, addition of only 10 wt% of precipitated silica externally gives distinct aggregations. [Pg.65]

It is demonstrated in Figure 22.11 that the quasi-static stress-strain cycles at different prestrains of silica-filled rubbers can be well described in the scope of the above-mentioned dynamic flocculation model of stress softening and filler-induced hysteresis up to large strain. Thereby, the size distribution < ( ) has been chosen as an isotropic logarithmic normal distribution (< ( i) = 4> ) = A( 3)) ... [Pg.619]

The Payne effect of carbon black reinforced rubbers has also been investigated intensively by a number of different researchers [36-39]. In most cases, standard diene rubbers widely used in the tire industry, bke SBR, NR, and BR, have been appbed, but also carbon black filled bromobutyl rubbers [40-42] or functional rubbers containing tin end-modified polymers [43] were used. The Payne effect was described in the framework of various experimental procedures, including pre-conditioning-, recovery- and dynamic stress-softening studies [44]. The typically almost reversible, non-linear response found for carbon black composites has also been observed for silica filled rubbers [44-46]. [Pg.5]

Chapman, A.V. Tinker, A.J. The effect of low molecular weight polybutadiene as processing aid on properties of silica-filled rubber compounds. Kautschuk Gummi K 2003, 56, 533. [Pg.2271]

Diamine salts of fatty acids are used as multifunctional additives in natural rubber compounds filled with carbon black.They affect the elastomer-carbon black interface. With an increased concentration of multifunctional additive, the concentration of bound rubber decreases but dispersion of carbon black is improved. In silica filled rubber, multifunctional additive also improves the dispersion of silica, but in addition, it decreases the negative influence of silica filler on vulcanization rate. [Pg.555]

Figure 10.14. Characteristic types of Mullins softening in silica-filled rubber vulcanizates. Highly reinforcing fillers give more stress-softening than slightly reinforcing or nonreinforcing materials. (Sellers and Toonder, 1965.)... Figure 10.14. Characteristic types of Mullins softening in silica-filled rubber vulcanizates. Highly reinforcing fillers give more stress-softening than slightly reinforcing or nonreinforcing materials. (Sellers and Toonder, 1965.)...
Combining silanes with silica led to high-performing silica-filled rubber compounds. Organofunctional silanes with polysulfane groups such as bis-(3-(triethoxysilyl)propyl)tetrasulfane (TESPT) and bis-(3-(triethoxysilyl)propyl)disulfane (TESPD) (Fig. 12) are utilized to improve dispersability of silica in the rubber matrix. [Pg.567]

Even though the final performances of the cured rubber compounds are very important, the process stability is also of great importance in manufacturing and cannot be neglected when choosing the silane structure. Figure 13 shows strain/modulus curves of three silica-filled rubber compounds using TESPT, TESPD, and mercaptopropyitriethoxysilane, respectively. [Pg.569]

The properties of silica-filled rubber and composites depends primarily on the association of individual primary silica particles in the final material. The association of primary particles is believed to be a reversible process responsible for the physical properties of the filled material at low strain levels. This process is furthermore believed to an essential mechanism explaining the improvement of dynamic properties of filled rubber, as opposed to carbon black, silica particles are characterized by a strongly polar surface able to generate a strong interaction. The interaction is reversible and leads to reduced hysteresis. [Pg.706]

L. Ladouce, Y. Bomal, L. Flandin, D. Labarre, Dynamic mechanical properties of precipitated silica filled rubber Influence of morphology and coupling agent . Paper No. 33, 157 meeting of the Rubber Division, American Chemical Society, Dallas, Texas, April 4-6, 2000. [Pg.608]

H. D. Luginsland, J. Frohlich and A. Wehmeier, Influence of Different Silanes on the Reinforcement of Silica-filled Rubber Compounds, paper No. 59 presented at the ACS Meeting, Rhode Island/USA, April 24-27 Rhode Island/USA, 2001. [Pg.135]

Micron-sized fillers, such as glass fibers, carbonfibers, carbon black, talc, and micronsized silica particles have been considered as conventional fillers. Polymer composites filled with conventional fillers have been widely investigated by both academic and industrial researchers. A wide spectrum of archival reports is available on how these fillers impact the properties. As expected, various fundamental issues of interest to nanocomposites research, such as the state of filler dispersion, filler-matrix interactions, and processing methods, have already been widely analyzed and documented in the context of conventional composites, especially those of carbon black and silica-filled rubber compounds [16], It is worth mentioning that carbon black (CB) could not be considered as a nanofiller. There appears to be a general tendency in contemporary literature to designate CB as a nanofiller - apparently derived from... [Pg.360]

With the advent of HDS, the ability to disperse silica to levels equal to that of carbon black is now possible for the creation of highly silica-filled rubber compounds. Thus, there has been a revolution in growing use of silica in place of carbon black in tires since the early 1990s, requiring growing use of specific coupling agents, whose number and chemistries have also expanded in this time period. A description of this class of rubber chemicals follows. [Pg.7262]

Table 12. Selected Organofunctional Silane Coupling Agents for Silica-Filled Rubber... [Pg.7264]

Owing to the different mechanical properties, filler particles can be in most cases differentiated from the polymeric matrix in SFM. Examples include carbon black or silica-filled rubbers, carbon-black-filled polymer blends or salt-loaded block copol5nner micelles. For the latter case, Spatz and co-workers demonstrated... [Pg.7474]

The use of stearic acid as a modifier for silica and other fillers like CaCOs and Mg(OH)2 has been reported. The authors found that the presence of adsorbed stearic acid on the filler surface reduces the hydrophilicity of the silica surface and enhances the compatibility between filler and matrix, which may lead to an improvement in filler dispersion and the related mechanical performance of composites. Kosmalska et al also investigated the adsorption of DPG, ZnO and sulfur on the silica surface and reported that the bonding of DPG/ZnO and ZnO to silica causes a reduction in the surface energy of silica from 66 mN/m to 28.75 mN/m and 35.49 mN/m, respectively. A similar effect of ZnO on the surface tension of silica was also found by Laning et alP and Reuvekamp et al. The adsorption of that additive and its impact on the scorch time and reduction of the crosslink density in silica-filled rubber compounds have been frequently characterized. ... [Pg.169]

The effect of carbon black on hysteresis depends primarily on the particle size of the filler and is related to breakdown and reformation of the agglomerations and the network, to slippage of polymer chains around the periphery of the filler clusters and the presence of occluded rubber. Figure 13 shows the difference of the temperature profiles of carbon black and silica filled rubber compoimds. [Pg.106]

Silane adhesion promoters are manufactured globally. They have traditionally been manufactured in the United States, Europe, and Japan, but manufacturing facilities in China and Korea are supplementing the supply with high-quality products. The emergence of large-volume applications for silanes, especially in silica-filled rubber tires, has substantially increased the number of global suppliers. [Pg.570]

F. Yatsuyagagi, H. Kaidou, N. Suzuki, and M. Ito, Relationship between secondary structure of fillers and the mechanical properties of silica filled rubber systems , ACS Rubber Division Meeting, Providence, RI, April (2001)... [Pg.72]

Silica particles are commercially available in the same size range as carbon black (i.e., down to 0.01 pm or 10 nm). Silica has been commercial reinforcing filler since the 1940s. The processing of silica-filled rubber compounds is more difficult than with carbon black-filled compounds because polar interparticle forces make it more difficult to break up agglomerates [101]. [Pg.96]


See other pages where Silica-filled rubbers is mentioned: [Pg.108]    [Pg.198]    [Pg.225]    [Pg.347]    [Pg.81]    [Pg.4]    [Pg.288]    [Pg.85]    [Pg.713]    [Pg.372]    [Pg.544]    [Pg.545]    [Pg.742]    [Pg.761]    [Pg.185]    [Pg.372]    [Pg.152]    [Pg.196]    [Pg.510]    [Pg.134]    [Pg.562]   


SEARCH



© 2024 chempedia.info