engleski

Kinetic analysis of thermal degradation of the polyvinyl chloride/magnesium hydroxide blends

Thermal stability of poly(vinyl chloride)/magnesium hydroxide (PVC/Mg(OH)2) blends has been investigated by thermogravimetric analysis (TG) in dynamic heating regime. PVC/Mg(OH)2 blends were prepared by hot-melt extrusion (HME). According to TG analysis, PVC as well as PVC/Mg(OH)2 blends decomposes in two degradation stages. In order to evaluate the effect of Mg(OH)2 addition on the thermal stability of PVC, different criteria were used. It was found that by addition of Mg(OH)2 the degradation of PVC starts at higher temperatures and therefore Mg(OH)2 enhances the thermal stabilty of the PVC even at small loads up to 10%. By using multiple heating rate kinetics the activation energies of the PVC/PEO blends thermal degradation were calculated by isoconversional integral Flynn-Wall-Ozawa and differential Friedman method. According to dependence of activation energy on degree of conversion the complexity of degradation processes was determined. The addition of Mg(OH)2 increased the apparent activation energy value of the thermal degradation of PVC. However, the exception is blend 95/5 which showed the lowest value.

activation energy, fire retardant, magnesium hydroxide, poly(vinyl chloride), thermal degradation

nije evidentirano