Internal stresses in polystyrene fordem during modification of wood
Modification of wood by thermal-catalytic polymerization of styrene initiated at a temperature of 100 °C by a system comprising benzoyl peroxide and cumene hydroperoxide results in the formation of tensile stresses in polystyrene of the value of about 4.2 MPa. They are the result of addition of the stresses due to polymerization shrinkage in the range of 0.1—1.0 MPa and of the thermal stresses in the range of 2.8—3.2 MPa. Thermal stresses are connected with the decrease of polystyrene dimensions during its cooling to ambient temperature. Polymerization, process carried out at a temperature of 100°C causes a considerable „temperature” relaxation of stresses in polystyrene. Relaxation of stresses in polystyrene takes also piace during its storage at ambient conditions.
If you are interested in full versions of articles, please contact the editorial team of email@example.com