On Polymer Nanocomposites - Progress in Organic and Physical Chemistry: Structures and Mechanisms - page 227

cutting out line Ʉ = 1.5405981 Å) characteristic radiation of x-ray

tube with the copper anode. The diffraction picture in a range of corners 2

α 1 (length of wave λ

θ from 3 ° to

100 was registered by the plate with optical memory (IP detector) of the camera bent

on a circle. Measurements were spent on original powders nc-Si-36 and nc-Si-97, on
the pure ¿ lm LDPE further marked as PE, and on composite ¿ lms PE + 0.5% nc-Si-97
and PE + 1.0% nc-Si-36. For elimination of tool distortions effect diffractogram stan-
dard SRM660a NIST from the crystal powder LaB 6 certi¿ cated for these purposes by
Institute of standards of the USA was measured. Further it was used as diffractometer
tool function.
Samples of initial powders nc-Si-36 and nc-Si-97 for x-ray diffraction measure-
ments were prepared by drawing of a thin layer of a powder on a substrate from a
special ¿ lm in the thickness six microns (MYLAR, Chemplex Industries Inc., Cat.
No: 250, Lot No: 011671). Film samples LDPE and its composites were established
in the diffractometer holder without any substrate, but for minimization of structure
effect two layers of a ¿ lm focused by directions extrusion perpendicular each other
were used.
Phase analysis and granulometric analysis was spent by interpretation of the X-ray
diffraction data. For these purposes the two different full crest analysis methods [15,
16] were applied: (1) method of approximation of a pro¿ le diffractogram using ana-
lytical functions, polynoms, and splines with diffractogram decomposition on mak-
ing parts, (2) method of diffractogram modeling on the basis of physical principles
of scattering of X-rays. The package of computer programs WinXPOW was applied
to approximation and pro¿ le decomposition diffractogram ver. 2.02 (Stoe, Germany)
[17], and diffractogram modeling at the analysis of distribution of particles in the sizes
was spent by means of program PM2K (version 2009) [18].

°

17.4 DISCUSSION AND RESULTS
The results of mechanical tests of the prepared materials are presented to Table 1 from
which it is visible that additives of particles nc-Si have improved mechanical charac-
teristics of polyethylene.

TABLE 1 Mechanical characteristics of nanocomposite films based of LDPE and nc-Si.

Sample Tensile strength, kg/cm 2 Relative elongation at break, %

PE 200 - 450

100 ± 12

PE + 1% ncSi-36 122 ± 12 250 - 390

PE + 0.5% ncSi-97 380 - 500

118 ± 12

The results presented in the table show that additives of powders of silicon raise
mechanical characteristics of ¿ lms, and the effect of improvement of mechanical prop-
erties is more expressed in case of composite PE + 0.5% nc-Si-97 at which in compari-
son with pure polyethylene relative elongation at break has essentially grown.