In this study Klason lignins from Eucalyptus grandis (LEUG) and Pinus taeda (LPIT) were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using the Kissinger method. Thermogravimetric results showed that LPIT had higher thermal stability and also higher activation energy than LEUG. FTIR result...

thermal cracking of a heavy liquid hydrocarbon was performed in a laboratory scale tubular reactor. central composite design (ccd), was used as an experimental design method. the design variables were coil outlet temperature (cot), feed flow and rate steam ratio. maximum yield of ethylene was 30.37 wt% at cot, residence time and steam ratio of 869oc, 0.208 s and 1.22 g/g, respectively. maximum ...

Ageing and stabilization polymers is a major part of materials science. Aging of polymers defined as a set of chemical and physical transformations, leads to the loss of their set the desired properties. The main role in these transformations belong to chemical processes of degradation and crosslinking of macromolecules. Processes decomposition and structuring polymer conjugates include radical...

PhotoDSC has been applied to follow the global kinetics of chain scissions resulting from the UV light irradiation or from the thermal degradation of a high molecular weight PEO (4 x 10(6) g x mol(-1)). Infrared spectroscopy, XRD measurements and rheology experiments were performed to evidence the occurrence of chain scissions. Melting energy was used as a tool to quantify the extent of the deg...