Chemical Physics Letters
Research paper
Study on the pyrolysis characteristics of a series of fluorinated
cyclopentenes and implication of their environmental influence
,
,c
Zhenhai Wua, Yuanyuan Jia b, Hong Lia, Fang Bia, Yanqin Rena, Rui Gaoa, Chenfei Liua
,
,
,
,*
Ling Lia, Hao Zhanga d, Xin Zhanga e, Xuezhong Wanga
a State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
b College of Earth Sciences. Jilin University, Changchun 130061, China
c School of Science, China University of Petroleum, Beijing 102249, China
d School of Science, China University of Geosciences, Beijing 100083, China
e Environmental Research Institute, Shandong University, Jinan 250100, China
A R T I C L E I N F O
A B S T R A C T
Keywords:
3,3,4,4,5,5-hexafluorocyclopentene
(6FE),
1,3,3,4,4,5,5-heptafluorocyclopentene
(7FE)
and
octa-
Cyclic-HFOs
fluorocyclopentene (8FE) are considered as new generation of potential chlorofluorocarbons substitutes. To
investigate the thermostabilities, tubular furnace experiments were designed over temperature range of 500-
850℃. The results show that 6FE, 7FE and 8FE are all stable below 650 ℃, thus have good stabilities in common
storage and practical use condition. Furthermore, considering the short atmospheric lifetimes (several months),
low global warming potentials (GWPs, less than 119) and zero ozone depletion potentials (ODPs), the compounds
seem no big influences on the climate change.
Pyrolysis decomposition
Pyrolysis mechanisms
Environmental influence
1. Introduction
applicable at a small scale. Several experimental studies were performed
and proved that the polymer film deposition rate in c-C5F8 is higher than
Chloridated and bromided materials were once used widely in the
fields of fire extinguishing, cleaning, refrigerating and foam making
[1,2]. But due to the stratospheric ozone depletion potentials (ODPs)
and high global warming potentials (GWPs), the Montreal Protocol and
its amendments has banned the use of these materials [3,4]. For
example, the atmospheric concentration of trichlorofluoromethane
(CFC-11), which ranks the second-most abundant chlorofluorocarbon,
has declined substantially since the mid-1990 s [5]. However, recent
reports pointed that the decline of the atmospheric concentration of
CFC-11 was slowdown after 2012, suggests global emissions have
increased [6,7]. The replacements of the ozone depletion substances
(ODS) seem to be urgent under this situation. Unsaturated fluorinated
alkenes [8,9] and fluorinated ketone [10,11] have been proposed as
potential etching agent, refrigerants and extinguishant. For example,
perfluoro-2-methyl-3-pentanone (PFMP), marketed as Novec 1230 by 3
M, has been proposed as a fire extinguishing replacement for chloro-
fluorocarbons (CFCs) and Halons [12]. Octafluorocyclopentene (8FE) is
used as an etching and cleaning gas in semiconductor processing in place
of CF4, C2F6, NF3, SF6, and c-C4F8 [13], which has been industrially
in c-C4F8 about 50% and leads to higher selectivity and better perfor-
mance of c-C5F8 [14,15]. Moreover, 3,3,4,4,5,5-hexafluorocyclopentene
(6FE) and 1,3,3,4,4,5,5-heptafluorocyclopentene (7FE), which have the
same structure, are now being exploited the use as heat pump fluids,
etching agents and important industrial intermediate materials [16,17].
Hence prior to large-scale commercial application, environmental
influence, toxicity and thermal stability should be considered first.
Environmental influences, such as stratospheric ozone depletion po-
tentials, global warming potentials, formation of secondary noxious or
toxic degradation products, should be considered in the commercial
employing of chemical materials [18]. The atmospheric lifetime of 6FE
is shown to be 107 days and the global warming potentials (GWPs) for
20, 100, and 500 years were 54, 15, and 4, respectively [19]. As for 8FE,
the atmospheric lifetime and the 100-year time horizon global warming
potentials value of 8FE (c-C5F8) have been estimated to be 104 days and
28 [20]. They all show no big influence on the environment. In-
vestigations of the acute inhalation and oral toxicity values of these
materials have shown nowhere. 1,1,2,2,3,3,4-heptafluorocyclopentane
(7FA) which has a similar carbon skeleton and elements, seems have
* Corresponding author.
Received 9 September 2020; Received in revised form 15 November 2020; Accepted 21 November 2020
Available online 28 November 2020
0009-2614/© 2020 Published by Elsevier B.V.