Infrared emissivity property study and conformational analysis
of helical polysilane
Muyang Zhang ,
School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and
Engineering Laboratory, Nanjing 211189, China
Zhangjiagang Kangdexin Photoelectric Material Co., Ltd., Zhangjiagang, Jiangsu 215600, China
Correspondence to: Y. Zhou (E -mail: email@example.com)
Left and right single-handed helical polysilane (L-HPS and D-HPS) and racemic helical polysilane (R-HPS) were synthe-
sized by the Wurtz-type coupling reaction. The chiral dichloro(methoxycarbonyl ethyl propyl ether)methylsilane monomers applied
in copolymerization were derived from methyl
-lactate. The obtained polymers were characterized by
C nuclear magnetic
resonance, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, circular dichroism spectroscopy, gel permeation
chromatography and X-ray diffraction. Infrared emissivity (IRE) values were also investigated. Compared to R-HPS, L-HPS, and D-
HPS, a pair of mirror image, showed higher crystallinity, better thermal stability, and lower IRE (8–14 mm) at the values of 0.592
and 0.576, respectively. The higher regular secondary structure of HPSs was attributed to the formation of intermolecular hydrogen
bonds. To further study the configurations of L-HPS, D-HPS, and R-HPS, rotational isomeric state scheme with molecular dynamics
simulation have been utilized.
2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46335.
copolymers; optical and photovoltaic applications; optical properties; thermogravimetric analysis; X-ray
Received 5 September 2017; accepted 3 February 2018
Enantiomers, also called optical isomers, are a pair of nonsuperim-
-lactate and (1)-methyl
As the starting material in helix-sense polymerization,
enantiomers were utilized in different ways.
In recent years,
enantiomer-selective polymerization based on racemic monomeric
mixtures have been applied in the fabrication of single-handed heli-
In polymerization process, one of the enantiomers
were preferentially polymerized over antipode with the help of chiral
However, the use of chiral sources causes many problems:
the unrecyclable optically active catalysts and initiators result in low
chiral economy; additional chiral units polymerized in macromole-
cules lead to uncontrollable helical conformation.
To avoid these problems, strategy relying on single-handed chiral
starting material was selected.
In previous works, helical poly-
mers like polyurethane, polyacetylene, and polysilane were syn-
thesized and utilized in infrared stealthy.
Their low infrared
emissivity (IRE) property was attributed to the intermolecular
interaction and influenced by the polymer’s helical conformation.
For instance, polyurethane with left-handed helical structure
demonstrated superior performance at low infrared emission as
compared to racemic and right-handed samples.
To further clar-
ify the relationship between polymer’s conformation and IRE,
left-, and right-handed helical polysilanes resulting from methyl
acetate enantiomers were prepared.
Linear polysilane is a kind of polymer constructed by one-
dimensional silicon backbone with functional sidechain
To be more specific, poly(di-n-hexylsilane) (PDHS)
possesses a random distributed 7/3 helical backbone with the
dihedral angle around 1508 which ascribes to the noncovalent
interaction between hexyl side groups and 115.48 bond angle of
In the work of Sasanuma et al.
UV absorption max-
imum was determined by the average dihedral angle of PDHS.
According to the sergeants and soldiers effect and the majority
rule, the chiral direction and compositional ratio of single-
handed functional groups affect polymer’s helicity.
the incorporation of chiral (methoxycarbonyl ethyl propyl
ether)methylsilane (MMS) linkage leads to the single-handed
helical conformation and low infrared emission of polysilane.
The property of low IRE originated from polymer’s unsatura-
tion degree and noncovalent interactions between functional
groups. HPSs’ unsaturation degree which results from the car-
boxyl group and their noncovalent interaction were mainly
Additional Supporting Information may be found in the online version of this article.
2018 Wiley Periodicals, Inc.
J. APPL. POLYM. SCI. 2018, DOI: 10.1002/APP.46335
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