Backbone toluene sulfonation

Conjugated polymers, in the undoped state, present remarkable nonlinear optical properties23. The material which has been most thoroughly investigated ever since 197624 is polydiacetylene para-toluene sulfonate (PTS). The polydiacetylene backbone consists of a... 

Figure 4.49 Microplant for toluene sulfonation with falling-film microreactor as central apparatus and unitized backbone as fluidic bus system (by courtesy of Elsevier) [315],...

In the following, the concept of micro modular process engineering is introduced together with the backbone interface developed in order to realize this modular approach. The integration of sensors and an electronic bus system is also described, and the physical characterization of the backbone is discussed within a case study of the enantioselective synthesis of organoboranes. Within the second case study, the sulfonation of toluene with gaseous sulfur tri oxide, the backbone system together with the micro structured devices used is finally assessed based on its application to chemical synthesis. 

Case Study 2 [C 2] Chemical Characterization of the Backbone Using the Sulfonation of Toluene with Caseous S03... 

Precise control of concentration and residence time can increase the selectivity of the sulfonation of toluene, as this allows to optimally set the interplay between the readions 4.4.1-4.4.4 [315,316], The highly exothermic nature of the reaction demands for good temperature control. A single microreador is not suited to condud the various readion steps with all their different needs on temperature and residence time. Thus, a continuously operated plant with many microflow tools was developed. The plant design was based on a fluidic backbone providing unitized ports and plant unit sites to facilitate the connection of microstructured components from different suppliers (see Figure 4.49). 

You may already be familiar with ion-exchange resms and we will start with them. They are commonly based on the co-polymer of styrene and 1,4-divinyl benzene we discussed earlier. The polymerization is carried out in an emulsion in water so that the organic molecules are in tiny droplets. The resulting polymer forms as more or less spherical beads of less than a millimetre in diameter. They can be put through a series of sieves to ensure even sizes if required. The surface of each bead bristles with benzene rings (attached to the polymer backbone) that can be sulfonated in the para position just like toluene. 

Weiss at al.(11) observed similar effects of solvent polarity on the solution behavior of copolymers of styrene and sodium styrene sulfonate and the Na-salt of an SPS with a lower backbone molecular weight than that studied by Lundberg and Phillips. Weiss and co-workers observed no such behavior with a mixed solvent of toluene (e 2.4) and methanol (c 32 6). Insight of the differences in the solution behavior of Na and Mg salts of the carboxylate ionomers in DMF reported by Schade and Gartner, it is worth noting that neither Weiss et al. nor Lundberg and hillips reported data in polar solvents for cations other than Na. ... 

Backbone interface based on the bus concept where the flow passes through a central spine has been developed [12]. The modular backbone allows both commercial and demonstration type of microstmctured devices to be coupled in all three dimensions in a flexible and easy manner. Microstmctured heat exchangers, reactors, and mixers made of different manufacturers are surface-mounted on this backbone. The backbone itself consists of elements which can be combined individually and flexibly in all directions, according to the demands of the plant to be built. The backbone provides the flow paths for fluids and electrical conduits for power supply and signal transmission of sensors and actuators as shown in Fig. 5. With this united microreactor system, sulfonation of toluene with gaseous SO3 was successfully conducted to give... 

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