Glass borosilicate bulbs

Irradiation Procedure. Reaction mixtures were prepared at room temperature by transferring desired quantities of reactants from their storage bulbs to the reaction vessel, a 500-cc. spherical borosilicate glass flask attached to the vacuum line by a section of glass capillary tubing and a 4-mm. bore threaded glass valve with a Teflon plug (Fischer and Porter 795-609). Prior to each experiment this vessel was baked under vacuum at 500°C. for 12 or more hours. 

Borosilicate (usually 5-13% B203) Very good thermal shock resistance and chemical durability easy to melt and shape Not suitable for longterm high temperature use Labware kitchenware special light bulbs glass pipe sealed beam headlights... 

Reagents. Difluoramine was prepared from tetrafluorohydrazine (Air Products, Inc.) and thiophenol by the method of Freeman, Kennedy, and Colburn (3). It was purified by fractional condensation in a high vacuum system and was stored in a borosilicate glass bulb attached to the vacuum line. 

In the photolytic process, a 500-ml. borosilicate glass bulb containing 1.5 grams (8.3 mmole) of tert-buty iodide and 1.58 grams (15.2 mmole) of tetrafluorohydrazine was illuminated with a 300-watt Reflectorflood lamp at a distance of 15 cm. for 24 hours. Upon working up the reaction mixture as described above, 0.4 gram of er -butyldifluoramine was obtained. 

Distilling-flask delivery side arms usually made from tubing of about 6 mm diameter, and are easily broken. These flasks are, or should be, made from borosilicate glass and are easily repaired. The remnants of the delivery tube should be removed and a neat hole, about 8 mm diameter, blown in the flask neck. A previously prepared tube, 15 cm long, 8 mm diameter and of medium or heavy walled glass, has one end fire-polished and the other end slightly flared, as shown in Fig. 8.4. The flared end is joined to the flask neck, blown and pulled so that it is inclined downwards, towards the flask bulb. The flask neck, in the region of the delivery tube join, is flame annealed. 

The dilatometer should be made of borosilicate glass shape and dimensions are given in Fig. 6.2. The bulb of the dilatometer should have a volume of... 

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