Elastomers, additives Coupling agents

Two major breakthroughs have transformed this facility product into a reinforcing filler that can achieve all carbon black mixes properties with, in addition, a decreased hysteresis of major interest for tire applications. The first step was made in the 1970s by Wolff, who proposed a specific silane coupling agent, the TESPT [11]. The second step arises in the 1990s with an R. Rauline s patent, which introduces the use of specific precipitation silica, elastomers, and mixing conditions to achieve reinforcement [12],... 

Manchado et al. [127] described the synthesis of layered sUicate/natural rubber nanocomposites by mechanical and solution mixing. It was found that the filler and the polymer show good compatibility by solution blending. Addition of a coupling agent, namely bis(triethoxysilylpropyl)tetrasulfane (TESPT), could improve the adhesion between the filler and elastomer. 

The titanates are most often used as in situ coupling agents dissolved in a suitable vehicle. Because of the breadth of titanate chemistry commercially available, a water, solvent or oil based diluent can usually be conveniently found. For example, titanate can be added to an elastomer in the process oil before filler addition. The matrix itself can also serve as diluent, as in the case of polyolefins where a neoalkoxytitanate can be blended into the melt flux prior to filler addition. 

The synthesis of polysulfide elastomers involves the use of a small amount of trichloroalkane in addition to dichloroalkane and sodium sulfide in order to form a branched polymer. The prepolymer is treated with a mixture of sodium hydrosulfide and sodium sulfite followed by acidification to convert all end-groups to thiol groups. Further polymerization and crosslinking is achieved by oxidative coupling of the thiol end-groups by treatment with lead dioxide, p-quinone dioxime, or other oxidizing agent... 

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