Implementation of a low field time-domain NMR scanner as a diagnostic tool in the production of new polymer components is described in the context of qualification of a new QA/QC device. A study to determine the optimal experimental parameters was performed and a robotic autosampler was built to enable scanning of multiple pads.Relationships between T 2 values and physical properties of DC745 slabs were investigated, and the appropriate sampling parameters for the production setting were determined. Two versions of a robotic autosampler were built, and for the component described here a fourth radial axis was required in addition to traditional X, Y, and Z movement to eliminate the large variability in T 2 due to inconsistent sample coverage caused by complex rib geometry of the component. Data show that with appropriate choice of experimental conditions of the NMR detector and the detection geometry of the 1 robotic autosampler, sufficient resolution of variations in crosslink density on the millimeter scale could be determined. All data to date demonstrates that low-field NMR devices are a feasible tool for use in production settings for non-destructive quality control of polymer components.

Zu den bis jetzt nur wenig untersuchten Stoffen aus demGebiete der Kohlehydrate gehort der Holzxucker oder die Xylose, welche K o c h 3, zuerst hergestellt hat.Die Xylose entsteht durch Hydrolyse mittelst verdunnter Saure aus dem Nolxgumnzi, welches mit 5-bis 10procentiger Natronlauge aus Holz extrahirt wird. Das Holzgummi ist in unreinem Zustande wohlzuerst von P o u m a r e d e und F i g u i e r 4 ) abgeschieden und von T h. T h o m s e n 5, als besondere Substanz aufgestellt worden. Vor T h o m s e n oder fast gleichzeitig mit ihm haben D r a g e n d o r f f und seine Mitarbeiter vie1 uber gummiartige Stoffe aus Holz gearbeitet, besonders S t a c kr n a n n ' j ) , K o r oil"),

210. H. J. Wheeler und B. Tollens: Ueber die Xylose (Holzzucker) und das Holzgummi. (Vorgetragen in der Sitzung von Hm. B. Tollens.) Aus einer griisseren , abgeschlossenen und bald zu publicirenden

The diamine reagent 1,2-bis(2-aminophenylthio)ethane is no longer commercially available but is still required for the synthesis of the bismaleimide resin, APO-BMI, used in syntactic foams. In this work, we examined the hydrolysis of benzothiazole followed by reaction with dichloroethane or dibromoethane. The deprotonation of 2-aminothiophenol followed by reaction with dibromoethane was also investigated and later optimized for scale-up by scrutinizing all aspects of the reaction conditions, work-up, and recrystallization. On bench-scale, the optimized procedure consistently produced a 75-80% overall yield of finely divided, high purity product (>95%). The material was also produced on both a 100 lb scale and a 200 lb scale using the optimized process, giving high quality material in excellent yield.