1999 Volume 48 Issue 7 Pages 699-704
A polymer sample was cryogenically crushed in a sample vessel by a ball located in the vessel through repeated vertical movements of the vessel in liquid nitrogen. The composition of the ball, pre-cooling period before crushing and the crushing period were investigated in relation to the optimum condition for polymer crushing. As a result, the best method found is to use a tungsten carbide ball, 10 min of pre-cooling and 10 min of crushing. Under these conditions, each 3 g polymer sample was crushed into particles with an average size of 100150 μm. Cryogenical crushing increased the efficiency of solvent extraction for the additives from the polymer (HDPE) by 3.5 times compared to the case of extraction from an HDPE pellet. Also, the amount of the volatile organic compounds from the crushed HDPE increased by 2.6 times compared to that from an HDPE pellet. We clarified that the IR transmission spectrum of vulcanized NR-SBR can be measured after cryogenic crushing of the rubber together with KBr.
