Comparative Study of Kinetics of the Thermal Decomposition of Polypropylene Using Different Methods

Abstract

The thermal degradation kinetics of powder isotactic polypropylene was investigated in a thermobalance system, at non-isothermal heating conditions with heating rate of 5, 10, 15, and 20°C min À1 in the temperature range of 30-600°C under nitrogen atmosphere. The apparent activation energy (E a ) was determined using Ozawa-Flynn-Wall, Tang Wanjun, and Coats-Redfern (modified) methods. The apparent activation energies range from 61.3 to 110.9 kJ mol À1 . Increasing the heating rate shifted the T max to a higher level. The lower activation energy observed indicates the breakage of the bonds at weak links. Moreover, the values of activation energy are significantly controlled by the heating rate, level of conversion, and calculation technique. A comparison among the different techniques has been made on the basis of the apparent activation energy from the TG data. The activation energies determined by all the three methods are in good agreement with each other. Furthermore, the pyrolysis of model polypropylene was carried out over the temperature range 350-415°C in a salt bath using Pyrex reaction vessel. The gaseous fraction produced was collected in gas sampling bag and monitored gas chromatographically. The major hydrocarbons detected were methane, propylene, propane, 2-methylpentane, 2,4 dimethylpentane, and 2,4 dimethylheptane.

Characterization, thermal behavior, and electrical measurements of poly[4‐(2‐bromoisobutyroyl methyl)styrene]

“…Most of the researchers have used non‐isothermal methods for the kinetic study of a polymer during thermal decompositions. In non‐isothermal measurements, the decomposition mechanism defers from one temperature to another . Figure a shows the non‐isothermal TG curve for the poly(BBMS) at the following heating rates: 3, 7,10, 20, 30, and 40°C/min.…”

“…In addition, poly(BBMS) contains theoretically Table 2. [28,29] Figure 12a shows the non-isothermal TG curve for the poly(BBMS) at the following heating rates: 3, 7,10, 20, 30, and 40°C/min. But, it is expected that residue polymer with increasing elimination of hydrogen bromide from the poly(BBMS) structure may not be able to possess flame retardant property.…”

“…In nonisothermal measurements, the decomposition mechanism defers from one temperature to another. [28,29] Figure 12a shows the non-isothermal TG curve for the poly(BBMS) at the following heating rates: 3, 7,10, 20, 30, and 40°C/min. Some sets of kinetic data based on International Confederation for Thermal Analysis and Calorimetry (ICTAC) recommendations had been recorded in the literature.…”

Thermal decomposition study of polyvinyl chloride in the presence of commercially available oxides catalysts

“…However, acquiring suitable sites for landfilling is becoming more difficult every year. [2] Furthermore, the hazardous smoke produced as a result of incineration has become a burning issue. Therefore, these practices are now unacceptable in terms of harsh environmental pollution and strict legislation in the matter.…”

“…Previously plastic waste was incinerated or land filled. However, acquiring suitable sites for landfilling is becoming more difficult every year . Furthermore, the hazardous smoke produced as a result of incineration has become a burning issue.…”