Study on the Fiber Quantitative Analysis for Polysulfonamide High
Temperature Filtration Material
Gui Liu
1,2
1
Fujian Provincial Fiber Inspection Bureau,Fuzhou Fujian, China
2
Fujian Provincial Key Laboratory of Textiles Inspection Technology, Fuzhou Fujian, China
Keywords: Polysulfonamide(PSA), PI, Polytetrafluoroethylene(PTFE), quantitative analysis
Abstract: This paper focused on Polysulfonamide(PSA) high temperature resistance filtration material, the burn
characteristics, appearance, dissolution characteristic and infrared spectroscopy had been studied for three
commonly used fibers(PSA, PI, PTFE). The qualitative identification method was got by comprehensive
judgment. And on this basis, the quantitative analysis methods had been discussed for PSA blended product
with PI or PTFE or PI and PTFE. The verification test showed that the quantitative analysis method was
accurate and reliable, could be used to fiber content test for PSA blended filtration material.
1 INTRODUCTION
Polysulfonamide (PSA), a kind of aromatic
polyamide that macromolecular main chain contains
sulfuryl (-SO2-), is usually obtained through
reaction in solution condensation by 4, 4'- diamino
diphenyl sulfone (DDS) and paraphthaloyl chloride
(TPC). It not only has good physical and mechanical
properties, but also has good heat resistance, fire
resistance, electrical insulation, corrosion resistance,
radiation resistance and dimensional stability. For
the anti-thermal oxidation aging performance, PSA
significantly exceeds the aromatic polyamide fiber,
such as aramid 1313 and aramid 1414. In terms of
improving environmental protection and three
wastes treatment, as the 200-250℃ high temperature
flue gas filtration material, it has been widely used.
At the same time, it is also used as heat resistant,
flame-proof fabric, high temperature resistant
insulation paper.
At present, the research on PSA are mainly
focused on the manufacture and industrialized
application, especially in the industrial community
[1-
2]
. Domestic inspection agencies do not have a
systematic method for quantifying PSA fiber in
related high temperature filtration material. With the
rapid development of industry economy, the
application of PSA fiber has become more and more
extensive, and the identification technology of PSA
fiber and other fibers is becoming more and more
urgent. This paper focuses on high temperature
filtration composite materials, which are usually
made by Polysulfonamide (PSA), polyimide (PI)
[3-4]
and polytetrafluoroethylene (PTFE). In this paper,
the burning behaviour, appearance, chemical
solubility and infrared spectra of three kinds of
fibers were discussed, and the quantitative analysis
method of PSA fiber and other two fiber blended
products was also studied. It provides a reference for
the qualitative identification and quantitative
analysis method of high temperature filtration
material for PSA fiber.
2 EXPERIMENT
2.1 Reagent and Instrument
Sulfuric acid, hydrochloric acid, nitric acid, sodium
hypochlorite, sodium hydroxide, formic acid, ice
acetic acid, potassium thiocyanate, hydrofluoric
acid, cupric hydroxide, ammonium hydroxide, N, N-
dimethyl formamide, acetone, tetrahydrofuran,
phenol, carbon tetrachloride, arsenic ikari, 1, 4-
butyrolactone, dimethyl sulfoxide, cyclohexanone,
methylene chloride, dioxane, hydrogen peroxide,
xylene, etc. All the above reagents are analytical
pure.

Soxhlet extractor, thermostatic water bath,
analytical balance (accuracy is 0.0001g), triangle
flask with a plug, and glass vessels etc.
2.2 Sample and Pretreatment
PSA is provided by Shanghai Tanlon Fiber co., ltd.
P84(one of PI fiber) was purchased from evonik
industries-specialty chemicals (Shanghai) co., LTD.,
PTFE was purchased from Zhejiang Kertice Hi-Tech
Fluro-Material co,ltd. Three kinds of fibers are short
fiber. The sample was placed in the soxler extractor,
and was extracted for 1 hour with ethylether. After
the ether volatilization in a sample, the sample was
soaked in cold water for 1 hour, and then was
dehydrated and dried.
3 TEST RESULTS AND
DISCUSSION
3.1 Burning Test
3 fibers’ burning behavior were showed in table 1.
Table 1 3 fibers’ burning behaviour.
samp
le
b
urnin
g
b
ehavio
r
smell
resid
ue
close to
flame
in flame
away from
flame
PSA
no melt
no Shrink
melt,shrink
and brun
self-
extinguishi
n
g
little
paste
flavou
r
like
b
lack
coke
P84
no melt
no shrink
reddish
self-
extinguishi
ng
little
spicy
flavo
r
black
ash
PTF
E melt and
shrink
shrink and
burn
self-
extinguishi
ng
little
paraffin
flavour
little
b
lack
powe
r
3.2 Microscopic Examination
3 fibers’ longitudinal and cross sections were
showed in figure 1. As can be seen from figure 1, the
longitudinal section of PSA is smooth and grooved,
and cross-section is close to circle. The longitudinal
section of P84 is smooth and grooved, and the cross-
section is trifoliate. Most PTFE fiber’s longitudinal
section is like flat belt, which has obvious long
stripe and horizontal stripes. The fiber diameter
difference is big, which has split ends. The cross-
section is close to oval and irregular polygon.
(a) (b)
(c) (d)
(e) (f)
Fig.1 3 fibers’ longitudinal and cross section.(a)and (b)is
PSA, (c) and (d) is P84, (e) and (f) is PTFE .
3.3 Dissolution Test
3 fibers’ Chemical solubility were showed in table 2.
reagent
r
oom temperature
b
oiling
PSA P84 PTFE PSA P84 PTFE
95%-98% sulfuric aci
d
SS I S S I
75% sulfuric aci
d
II I S II
36%-38% hydrochloric
aci
d
I I I I I I
20% h
y
drochloric aci
d
I I I I I I
1mol/L sodium
h
yp
ochlorite
I I I I I I
5% sodium h
y
droxide I I I I I I
65%-68% nitric aci
d
II I S SI
88% methane aci
d
I I I I I I
99% acetic aci
d
I I I I I I
h
y
drofluoric aci
d
I I I - - -
copper ammonia I I I I - -
65% potassium
thiocyanate
I I I I I I
tetrachloride I I I I I I
x
y
lene I I I I I I
dimethylformamide
(
DMF
)
S I I S S I
acetone I I I I I I
tetrah
y
drofuran I I I I I -
p
henol I I I I I I
p
henol
/
tetrachlorethane I I I I I I

1, 4-
b
ut
y
lene I I I I I I
dimethylsulfoxide
(
DMSO
)
S I I S I I
cyclohexanone I I I I I I
dichloromethane I I I I I I
d
ioxane I I I I I I
eth
y
l acetate I I I I I I
p
y
ridine I I I I I I
Note1：symbol description S-- soluble，I—Insoluble.
3.4 Infrared Test
Take the right amount of samples and place them
directly on the germanium crystal, rotate the fixed
button of OMNIC sampler to pressure the sample,
the attenuated total reflection (ATR) was used to get
the attenuated full-reflection infrared spectrogram of
the sample. The instrument test condition is as
follows: detector is dtgs-kbr; The wave number
resolution is 4 cm-1; the scanning number is 32
times; The wave number ranges are from 600 cm-
1to 4000 cm-1.
610.07
700.49
838.39
1134.06
1308.08
1402.21
1517.86
1667.19
97.8
98.0
98.2
98.4
98.6
98.8
99.0
99.2
99.4
99.6
99.8
100.0
1000 2000 3000 4000
Figure 2. infrared spectrogram of PSA.
723.23
819.55
1115.14
1248 .76
1380 .30
1501 .27
1716 .36
94.5
95.0
95.5
96.0
96.5
97.0
97.5
98.0
98.5
99.0
99.5
100.0
100
.
5
5
1000 1500 2000 2500 3000 3500 4000
Figure 3. infrared spectrogram of P84.
1150 .97
1205 .84
87
88
89
90
91
92
93
94
95
96
97
98
99
100
1000
2000
3000
4000
Figure 4. infrared spectrogram of PTFE.
In figure 2, the absorption peak at 1667 cm-1 is
the stretching vibration of C=O; the peak at 1517
cm-1 is the benzene ring’s stretching vibration. The
two strong peaks near 1308 cm-1 and 1131 cm-1
belong to the asymmetric and symmetric
stretching vibration peak of the sulfone group. In
figure 3, the peak at 1778cm-1 and 1716 cm-1 are
asymmetric and symmetric stretching vibrations of
C=O from imide ring, peak at 1381cm-1 belongs to
stretching vibration of C-N; peak at 724cm-1
belongs to bending vibration of C=O from imide
ring.Figure 4 shows that PTFE has two strong peaks
around 1210cm-1 and 1150 cm-1. The peak around
1210cm-1 is asymmetric stretching vibration of CF2,
the other is symmetric stretching vibration of CF2.
The absorption peak of CF2 group is the strongest in
the spectrum of PTFE, which can also prove that
CF2 is the basic unit in the molecular chain.
3.5 Qualitative Analysis
In this paper four kinds of method burning test,
microscopic examination, chemical dissolution,
infrared spectrum test were used to identify above
three kinds of fibers. Burning test and microscopic
examination can only preliminary judge the fiber
category, and can't tell what it is. Combined with
chemical dissolution test, experimenter basically can
determine whether it contains in textiles. With the
increasing variety of fibers, Fibers with similar
dissolving properties may also constantly spring up.
Chemical dissolving method has its limitation.
Infrared spectroscopy was useful to further confirm
what it is. Therefore, from a variety of possibilities,
the above four methods were used to study the
qualitative analysis methods comprehensively.
Experimenters can fully identify which fiber it is and
quantify fiber content.

3.6 Quantitative Analysis
3.6.1 Two Component Fabric of PSA and
P84
Method using dimethylformamide(DMF).Dissolving
the PSA from known weight drying sample by
dimethylformamide, collecting residue, cleaning,
drying and weighing. The PSA mass content in
sample was calculated. The other fiber is P84, which
mass content could also be got.
Method using dimethylsulfoxide(DMSO).
Dissolving the PSA from known weight drying
sample by dimethylsulfoxide, collecting residue,
cleaning, drying and weighing. The PSA mass
content in sample was calculated. The other fiber is
P84, which mass content could also be got.
3.6.2 Two Component Fabric of PSA and
PTFE
Method using DMF and DMSO could also be used.
Dissolving the PSA from known weight drying
sample, collecting residue, cleaning, drying and
weighing. The PSA mass content in sample was
calculated. The other fiber is PTFE, which mass
content could also be got.
Method using 95-98% sulfuric acid Dissolving
the PSA from known weight drying sample by 95-
98% sulfuric acid, collecting residue, cleaning,
drying and weighing. The PSA mass content in
sample was calculated. The other fiber is PTFE,
which mass content could also be got.
3.6.3 Tri-component Fabric of PSA, P84 and
PTFE
When faced with tri-component fabric or needle
punched nonwovens of PSA, P84, we have two
steps. First, dissolving the PSA from known weight
drying sample by DMF, collecting residue, cleaning,
drying and weighing. Second, dissolving the P84
from known weight drying residue by boiling DMF,
recollecting residue, recleaning, redrying and
reweighing.The PSA mass content in sample was
calculated. The other fiber is PTFE, which mass
content could also be got.
Using above methods (3.6.1-3.6.3), the some
samples that known mass fraction were tested by
experimenter A and B. The parallel test results were
showed in table 3.
sam
ple
reagent
Mass
content
Parallel test results
Max
error
experimenter
A
experimenter B
PS
A/
P84
DMF
60.45/
39.55
60.87/
39.13
60.21/
39.79
60.75/
39.25
60.34/
39.66
0.32
DMSO
60.45/
39.55
60.19/
39.81
60.39/
39.61
60.85/
39.15
60.57/
39.43
0.40
PS
A/
PT
FE
DMF
52.88/
47.12
52.97/
47.03
51.51/
48.49
52.99/
47.01
52.78/
47.22
0.37
DMSO
52.88/
47.12
52.65/
47.35
52.99/
47.01
52.53/
47.47
52.71/
47.29
0.35
95-
98%
H2SO4
52.88/
47.12
52.73/
47.27
52.70/
47.30
52.93/
47.07
52.78/
47.22
0.18
PS
A/
P84
/
PT
FE
DMF
30.25/
35.42/
34.33
30.25/
35.42/
34.33
30.25/
35.42/
34.33
30.25/
35.42/
34.33
30.25/
35.42/
34.33
0.89
From table 3, in different experimental
conditions, the stability in chemical reagents of
polysulfonamide fiber and other fibers blended
product is good. The test result error of experimenter
A and B is no more than 1%, which is conform to
meet the requirements of GB/T 2910-2009 testing
standard. While using solvent to dissolve objective
blended products, the stability of the parallel test
performance is good, that was according with the
requirements of quantitative analysis. The
quantitative test results in table 3 showed that the
dissolving methods of polysulfonamide fiber and
other fibers blended products are feasible and valid.
4 CONCLUSIONS
In this paper, the four kinds of testing methods, such
as the burning test, microscopic observation,
chemical dissolution, infrared spectrum and so on,
were used to analyze 3 kinds of fiber (PSA, PI and
PTFE) comprehensively, which were commonly
used in high temperature filter material. A
comprehensive study on the qualitative analysis
methods of three kinds of fiber was carried out that
so as to realize the qualitative identification for three
fibers. On this basis, according to the chemical
dissolution characteristics, establish the quantitative
analysis methods were established. Through the
known mass content blended samples, The test result
error of experimenter A and B is no more than 1%,
which is conform to meet the requirements of testing
standard. The stability of the parallel test
performance is good. The dissolving methods of
PSA, PI and PTFE blended products are
feasible and valid. The testing results are accurate
and reliable.

ACKNOWLEDGEMENTS
This work is supported by the Research and
Development Program of Fujian Provincial Bureau
of Quality and Technical Supervision (Grant No.
FJQI2014019 and No. FJQI2016032).
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