Infrared autoclave

Figure 3.3 Side- and top-view of the in situ infrared autoclave. A IR window B Turbine rotor C Reagent addition D Thermocouple E Opening between upper and lower chamber F Electrical heaters C Kalrez O-rings (from Ref [6], reproduced by permission of Elsevier).

Example 5. Glycolysis of Polyurethanes with Propylene Oxide after Pretreatment with Ethanolamine.55 A rigid polyurethane foam (ca. 100 g) was dissolved in 30 g ethanolamine by heating. Excess ethanolamine was stripped, leaving a clear solution. Infrared and GPC analysis indicated that the clear solution obtained contained some residual polyurethane, aromatic polyurea, aliphatic polyols, aromatic amines, and N,N -bis(f -hydroxyethyljurea. Next the mixture was dissolved in 45 g propylene oxide and heated at 120°C in an autoclave for 2 h. The pressure increased to 40 psi and then fell to 30 psi at the end of the 2-h heating period. The product was a brown oil with a hydroxyl number of485. 

The deuterated bromide was then hydrolyzed in the following manner 78 g. (0.4 mole) of CH3(CH2)6CHDCH2Br and 200 ml. of 8% NaOH were placed in a 500-ml. stirring autoclave, which was heated to 165° for 1 hr. The product was washed free of alkali, dried over anhydrous sodium sulfate, and distilled in a packed column to give 37.4 g. of alcohol, b.p. 73°-75° at 3.5 mm., n 1.4305. This yield corresponds to a conversion of 72%. Mass spectrometric and infrared analysis of the deuterated alcohol indicated that the synthesis of the l-octanol-2-d was successful. 

Hardware sensors for the on-line monitoring of polymerization such as in batch reactors have been reviewed (Kammona et al. 1999). In Section 3.4 the use of ruggedized conversion sensors for fibre-optic near-infrared (NIR) spectroscopy during extrusion was described. In many ways, the requirements are simpler than for control of a batch reaction (as in a polymer-synthesis autoclave) since... 

The monomers were charged into the autoclave, and trace amounts of oxygen purged by the freeze-thaw technique. Irradiation was carried out with gamma rays from a (50Co source at various temperatures. CHC13, CH2C12, dimethylformamide (DMF), triethylamime (TEA), and p-benzoquinone were used as additives in the polymerization systems. Viscosity of the copolymers obtained was measured in Freon 113 at 35°C. Infrared spectra and x-ray diffraction patterns of the sample were also obtained. NMR measurements of (proton and fluorine) were also done. 

The results were obtained by continuous analysis of the hydrogenation medium. The reaction was performed in a 1 I autoclave equipped with a magnetically driven stirrer at a speed of about 1000 r/m. Samples were periodically withdrawn through a decanter tube from the bottom of the reactor. The main products were analysed by gas chromatography coupled with mass spectroscopy, NMR and infrared spectroscopy. 

This continuous process is operated from a centralized control panel which contains more than one hundred recorders and controllers. In addition, a data-reduction system continuously scans 70 key temper ures and at intervals types them out on the plant log. If, in the scanning process, a deviation from control is noted, the operator is notified by an alarm and the deviating data are recorded automatically. The control panel also contains start-stop switches for all motors. Included in the instrumentations are an infrared analyzer on the nitric oxide stream, a hydrogen analyzer on the derivative autoclaves, and a mass spectrometer for nitroparaffin analysis. 

Upon completion of the reaction, the autoclave is cautiously vented and coagulum is filtered off. The latex may be coagulated by the addition of a 5% aqueous solution of potassium aluminum sulfate. The coagulum is filtered off, washed with distilled water, and dried at reduced pressure at 60°C. The syndiotactic index of this latex is determined from the infrared absorptions at 635 and 692 cm" When prepared at 0°C, the resin has a syndiotacticity index of 2.1 and a glass transition temperature of 105°C. 

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