China Plastics ›› 2021, Vol. 35 ›› Issue (11): 104-110.DOI: 10.19491/j.issn.1001-9278.2021.11.016

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Pyrolysis and Thermokinetic Characteristics of Calixarene

ZHANG Dingran1(), LU Lingang2()   

  1. 1.Graduate School,China People's Police University,Langfang 065000,China
    2.Office of Academic Research,China People's Police University,Langfang 065000,China
  • Received:2021-05-21 Online:2021-11-26 Published:2021-11-23

Abstract:

The pyrolysis characteristics of calixarene and 4?tert?butylcalixarene were investigated by thermogravimetric analysis under a nitrogen atmosphere. Their activation energy and optimal mechanism function equation of the reaction process were studied using a thermal decomposition kinetic analysis method. The results indicated that 4?tert?butylcali?xarene exhibited the same initial thermal decomposition temperature as calixarene due to the instability of tert butyl groups. Hydrocarbons presented a decomposition temperature of about 160 ℃ earlier than calixarene. Their subsequent decomposition process was almost the same with calixarene (namely the bridged methylene cleavage occurs and the thermal cracking of the parent benzene ring). The residual char of 4?tert?butylcalixarene was slightly higher than calixarene by 10 %. The pyrolysis kinetic analysis demonstrated that the calixarene exhibited activation energy of 387.87 and 376.28 kJ/mol according to the Kissinger and Flynn?wall?Ozawa methods, respectively. According to the Coats?Redfern method, the pyrolysis mecha?nism function of calixarene was determined to be gα)=[-ln(1-α)]2/5, and the reaction order n was 2/5. Based on this result, the non?isothermal pyrolysis mechanism was determined as a random nucleation and subsequent growth reaction. The pyrolysis mechanism function of 4?tert?butylcalixarene was deterined to be gα)=[-ln(1-α)]1/2, and the reaction order n was 1/2, assigned to the non?isothermal pyrolysis mechanism as a result of the random nucleation and subsequent growth reaction.

Key words: calix[6]arene, 4?tert?Butylcalix[6]arene, thermogravimetry, heating rate, thermal decomposition kinetics

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