A reusable metal crucible for use in differential scanning calorimetry analysis of closed reaction system samples

Abstract

A specially designed sample crucible has been developed and evaluated for use with differential scanning calorimetry to determine whether if an exotherm is present in a closed system without the use of a high pressure DSC cell. The problems associated with the use of a crimped aluminum sample pan, with its low pressure containment and chemical reactivity, are overcome with the use of these crucibles. This crucible eliminates the need to purchase a high pressure DSC cell, in which the chemically reactive aluminum pan is often used, and overcomes the high pressure DSC problems of duplication of results and noisy baselines. The crucibles are useful with samples containing volatile components or those which release gaseous by-products during decomposition. The crucibles are constructed of either 316L or Hastelloy B, have a volume of ≈ 60 μ 1, and have a removable glass liner for use with highly corrosive systems. The crucibles are reusable, with a screw-on cap containing a replaceable 400 psi “rupture disk” seal, and have an operating temperature range from < 0 to = 300°C. Many of the commercially available high pressure cells are not reusable, do not have chemically resistant liners and are difficult to seal properly. The determination of the calibration coefficient of a DSC cell using this sample crucible, both with and without the glass liner, will be presented and the value compared with the calibration coefficient determined using a typically sealed aluminum pan.