Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 1, pp. 157−161.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
I.A. Novakov, N.A. Rakhimova, Ya.V. Zubavichus, A.P. Krasnov, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 1,
AND POLYMERIC MATERIALS
Effect of 1,1,5-Trihydroperﬂ uoropentanol and Formulations
Based on It on the Structure of Oriented Polycaproamide Fibers
I. A. Novakov, N. A. Rakhimova, Ya. V. Zubavichus, and A. P. Krasnov
Volgograd State Technical University, Volgograd, Russia
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
Received April 1, 2008
Abstract—Polycaproamide fibers, unmodified and modified with 1,1,5-trihydroperfluoropentanol and its
formulations with copper diacetate bis(ε-caprolactamate) or N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-
benzenediurea, were studied by X-ray diffraction.
Polycaproamide (PCA) belongs to the group of ﬁ ber-
forming polymers which form the base of cord fabric 
and many textile materials . The molecular and crystal
structure of PCA was examined in numerous studies
[3–11]. It was found that PCA is partially crystalline.
Three crystal modiﬁ cation of PCA (α, β, and γ) are known
[3, 4, 7]. The total degree of crystallinity and the phase
composition of PCA are largely determined by the method
and conditions of sample forming. For PCA fibers,
the contribution of the amorphous phase is, as a rule,
insigniﬁ cant, whereas in PCA ﬁ lms formed from solutions
in formic acid the amorphous phase prevails .
The structure of PCA ﬁ ber is affected by chemical
treatment [12, 13], thermal activation , mechanical
activation , and treatment with low-temperature plasma
[16, 17]. It is known  that introduction of moisture into
PCA affects differently, depending on its amount, the state
of supramolecular formations in amorphous areas. This
leads to plasticization and antiplasticization phenomena.
At low moisture concentrations in PCA (up to 1.6%),
plasticization is observed, whereas further moistening
(up to 5.5% moisture content) leads to antiplasticization,
which is associated with difﬁ cult penetration of molecules
into ordered regions. The X-ray diffraction pattern of
a freshly formed thread is characterized by a diffuse
halo with no pronounced evidences of orientation. It
corresponds to the amorphous or ﬁ nely crystalline state
of the polymer of the mesomorphic structure. As the
thread is moistened, a stable crystalline structure of the
α-modiﬁ cation is formed (two clearly separated rings
in the X-ray pattern), with pronounced axial orientation
Storozhakova et al. suggested polyﬂ uorinated alcohols
(PFAs) of the general formula H(CF
PCA modiﬁ ers [19–25]. Molecules of these compounds
actively interact with the PCA macromolecule owing
to the presence of proton-donor HO and HCF
(the latter groups become acidic owing to strong
electron-withdrawing effect of the fluorine atoms)
and a perﬂ uorinated chain. At a ﬁ vefold excess of the
polyfluorinated alcohol, PCA fully dissolves with
a noticeable exothermic effect [19, 20].
Quantum-chemical calculations of intermolecular
interactions for PCA modiﬁ ed with PFA revealed increased
bond order between associated groups, suggesting
enhancement of hydrogen bonds –NH•••O=C< between
the adjacent macromolecules under the inﬂ uence of PFA
even at relatively low PFA concentrations (one PFA
molecule per several PCA macromolecules) [21, 22].
Modification of the PCA fiber with 1,1,5-tri-
hydroperfluoropentanol (TPFP) and formulations
based on it makes the polymer more resistant to both
photochemical and thermal degradation [22, 23].
Introduction of microamounts of PFA into PCA ﬁ lms
in the step of their forming  leads to an increase in
the content of the crystalline α-phase and in the size of
The goal of this study was to examine by X-ray
diffraction the effect of TPFP and formulations based