ISSN 0010-5082, Combustion, Explosion, and Shock Waves, 2018, Vol. 54, No. 3, pp. 309–315.
Pleiades Publishing, Ltd., 2018.
Original Russian Text
R. Zong, R. Kang, Y. Zhi, C. Liu.
Experimental Study on Pyrolysis
of Black Non-Charring Polymers
in the Reduced-Pressure Environment
Published in Fizika Goreniya i Vzryva, Vol. 54, No. 3, pp. 64–71, May–June, 2018.
Original article submitted August 2, 2017.
Abstract: A series of experiments on a black non-charring polymer in the low-pressure chamber is
conducted under diﬀerent external heat ﬂuxes. The surface and bottom temperatures and the mass
loss of the sample are measured. A parameter T
is introduced to describe the impact of pressure
on the surface temperature. There is a loose layer of the char residue left with signiﬁcant pyrolysis
bubbles under the low heat ﬂux, and the bubble size decreases with pressure. The parameter T
found to exhibit a signiﬁcant decline trend with increasing pressure, and the mass loss rate of the
sample decreases apparently as the pressure increases. However, under a high heat ﬂux, the char
residue is denser, and the pyrolysis bubbles are not observed. The value of T
and the mass loss
rate of the sample have no obvious relationship with pressure. The average pyrolysis rate is linearly
proportional to p
Keywords: reduced pressure, surface temperature, bottom temperature, mass loss rate, char
In recent years, polymers have been widely used in
industry and everyday life for their characteristics of low
cost and light weight. However, the huge amount of car-
bon and hydrogen atoms in polymers make them highly
ﬂammable and hazardous in terms of ﬁre . Therefore,
the study of the polymer combustion behavior is of great
importance. Pyrolysis is the ﬁrst step in gasiﬁcation
and in other thermochemical conversion processes .
The investigation of the inﬂuence of operating condi-
tions on their pyrolysis is important for understanding
the entire combustion process.
State Key Laboratory of Fire Science, University of Science
and Technology of China, Hefei, 230027 China;
Suzhou Key Laboratory of Urban Public Safety, Suzhou
Institute for Advanced Study, University of Science and
Technology of China, Suzhou, 215123 China.
School of Mechanical Engineering, Nanjing Institute
of Technology, 211167 China.
Some materials, such as polypropylene, polylac-
tic acid, and polyacrylonitrile butadiene styrene (ABS)
were classiﬁed as non-charring materials whose residual
mass obtained from heating mg-sized samples in the
temperature range from room temperature to 873 K in
an anaerobic environment was found to be below 5% .
If such materials are used in aircraft and spacecraft in-
dustry, their pyrolysis will take place in the low-pressure
and high-altitude environment, where the ambient pres-
sure is lower than atmospheric pressure. According
to the Rules of the Federal Aviation Administration
(FAA), the pressure in the cabins of spacecraft should
be equal to that at the altitude of 1500–2400 m [3, 4].
Pyrolysis in the course of polymer gasiﬁcation and heat
convection are aﬀected by pressure. Much attention has
been paid to the pyrolysis behavior in vacuum or atmo-
spheric pressure environment. Li et al.  performed
some atmosphere-controlled radiation-driven gasiﬁca-
tion experiments on a series of synthetic polymers, mea-
sured the mass loss rate and non-radiation surface tem-
perature, and conducted thermogravimetric (TGA) and
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