On Polymer Nanocomposites - Progress in Organic and Physical Chemistry: Structures and Mechanisms - page 226

As the origin materials for preparation ¿ lm nanocomposites served polyethylene
of low density (LDPE) marks 10803-020 and ultradisperse crystal silicon. Silicon
powders have been received by a method plazmochemical recondensation of coarse-
crystalline silicon in nanocrystalline powder. Synthesis nc-Si was carried out in argon
plasma in the closed gas cycle in the plasma evaporator the condenser working in the
arc low frequency category. After particle synthesis nc-Si were exposed microcapsu-
lating at which on their surfaces the protective cover from SiO 2 , protecting a powder
from atmospheric inÀ uence and doing it steady was created at storage. In the given
work powders of silicon from two parties were used: nc-Si-36 with a speci¿ c surface
of particles ~36 m 2 /g and nc-Si-97 with a speci¿ c surface ~97 m 2 /g.
Preliminary mixture of polyethylene with a powder nc-Si ¿ rms “Brabender” (Ger-
many) carried out by means of closed hummer chambers at temperature 135 ± 5 ɨ ɋ,
within 10 min and speed of rotation of a rotor of 100 min -1 . Two compositions LDPE
+ nc-Si have been prepared: (1) composition PE + 0.5% nc-Si-97 on a basis nc-Si-97,
containing 0.5 weights silicon %, (2) composition PE + 1% nc-Si-36 on a basis nc-
Si-36, containing 1.0 weights silicon %.
Formation of ¿ lms by thickness 85 ± 5 micron was spent on semiindustrial extru-
sion unit ȺRP-20-150 (Russia) for producing the sleeve ¿ lm. The temperature was
120-190 ɨ ɋ on zones extruder and extrusion die. The speed of auger was 120 min -1 .
Technological parameters of the nanocomposites choose, proceeding from conditions
of thermostability and the characteristic viscosity recommended for processing poly-
mer melting.
17.3 EXPERIMENTAL METHODS
Mechanical properties and an optical transparency of polymer films, their phase struc-
ture and crystallinity, and also communication of mechanical and optical properties
with a microstructure of polyethylene and granulometric structure of modifying pow-
ders nc-Si were observed.
Physico-mechanical properties of ¿ lms at a stretching (extrusion) measured in a
direction by means of universal tensile machine EZ-40 (Germany) in accordance with
Russian State Standard GOST-14236-71. Tests are spent on rectangular samples in
width of 10 mm and a working site of 50 mm. The speed of movement of a clip was
240 mm/min. The ¿ ve parallel samples were tested.
Optical transparency of ¿ lms was estimated on absorption spectra. Spectra of ab-
sorption of the obtained ¿ lms were measured on spectrophotometer SF-104 (Russia)
in a range of wavelengths 200-800 nm. Samples of ¿ lms of polyethylene and compos-
ite ¿ lms PE + 0.5% nc-Si-36 and PE + 1% nc-Si-36 in the size 3 × 3 cm were investi-
gated. The special holder was used for maintenance uniform a ¿ lm tension.
X-ray diffraction analysis by wide-angle scattering of monochromatic X-rays data
was applied for research phase structure of materials, degree of crystallinity of a poly-
meric matrix, the size of single crystal blocks in powders nc-Si and in a polymeric
matrix, and also functions of density of distribution of the size crystalline particles in
initial powders nc-Si.
X-ray diffraction measurements were observed on Guinier diffractometer: cham-
ber G670 Huber [14] with bent Ge (111) monochromator of a primary beam which are