Studies on the thermal degradation of poly
(phenylene sulfide sulfone)
Huadong Wang
a
, Jie Yang
b,
*, Shengru Long
b
, Xiaojun Wang
c
, Zheng Yang
b
,
Guangxian Li
c
a
The Faculty of Chemistry Sichuan University, Chengdu 610064, PR China
b
Institute of Materials Science and Technology Sichuan University, Chengdu 610064, PR China
c
The College of Polymer Materials Science and Engineering, Chengdu 610065 PR China
Received 19 April 2003; received in revised form 13 June 2003; accepted 5 July 2003
Abstract
The thermal degradation of poly(phenylene sulfide sulfone) PPSS was studied by thermogravimetricanalysis to determine the
reaction mechanism. Several tests were carried out at different heating rates. The influence of the heating rate in dynamic mea-
surements (5–40
C/min) on kinetic parameters, such as activation energies, was also studied. The activation energy of the solid-
state process was determined to be 214 kJ/mol using Kissinger’s method, which does not require knowledge of the reaction
mechanism. The value of the activation energy obtained using Flynn–Wall–Ozawa method was in agreement with that using Kis-
singer’s method. Different reaction mechanisms were used to compare with this value. Also the experimental data were compared to
master curves. Analysis of the experimental results suggested that the actual reaction mechanism was a D
n
deceleration type.
# 2003 Elsevier Ltd. All rights reserved.
Keywords: Thermal degradation; Kineticanalysis; Poly(phenylene sulfide sulfone); Activation energies
1. Introduction
Poly (phenylene sulfide sulfone) (PPSS) with the
repeating structural unit—(–p–C
6
H
4
–SO
2
–C
6
H
4
–S–p–)—
is a new polymer of the PPS class with good thermal
properties. In this work, thermogravimetricanalysis
(TGA) was used to determine the activation energy of
degradation of PPSS. The knowledge of the thermal
degradation behaviour of a polymer is very important
because it can be used to determine the final properties
for the use of a material, such as the upper temperature
limit of use. Attention has also been directed to the use
of thermogravimetricdata for the determination of
kineticparameters.
Many methods of kineticanalysis are based on the
hypothesis that, from a simple thermogravimetrictrace,
meaningful values can be obtained for parameters such
as activation energy, pre-exponential factor and reac-
tion order. Differential and integral methods will be
discussed later. The distinction of the two methods
depends on whether they are based on only one heating
rate or on more than one heating rate.
2. Experimental procedure
References to PPSS are mostly limited to either the
patent or commercial trade literature. Phillips Petro-
leum Company reported a manufacturing route in
which the polycondensation of 4,4
0
-dichlorodiphenyl
(DCDPS) was performed with Na
2
S at 200
C for 3 h in
N
2
atmosphere under high pressure [1,2]. We have pre-
pared PPSS at atmosphericpressure, using sodium sul-
fide as the nucleophile, 4,4
0
-dichlorodipheneyl sulfone as
activated aromatic halide, alkali and catalyst in a polar
organicsolvent at atmosphericpressure. The synthesis is
described briefly below (Scheme 1). The product was
0141-3910/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0141-3910(03)00266-0
Polymer Degradation and Stability 83 (2004) 229–235
www.elsevier.com/locate/polydegstab
* Corresponding author. Tel./fax: +86-28-85412866.
E-mail address: ppsf@scu.edu.cn (J. Yang).