Chemistry Reference
In-Depth Information
15.1 INTRODUCTION
The idea of different classes polymers representation as composites is not
new. Even 35 years ago Kardos and Raisoni [1] offered to use composite
models for the description of semicrystalline polymers properties number
and obtained prediction of the indicated polymers stiffness and thermal
strains to a precision of ±20%. They considered semicrystalline polymer as
composite, in which matrix is the amorphous and the crystallites are a filler.
The authors of Ref. [1] also supposed that other polymers, for example, hy-
brid polymer systems, in which two components with different mechanical
properties were present obviously, can be simulated by a similar method.
In Ref. [2] it has been pointed out, that the most important consequence
from works by supramolecular formation study is the conclusion that phys-
ical-mechanical properties depend in the first place on molecular structure,
but are realized through supramolecular formations. At scales interval and
studies methods resolving ability of polymers structure the nanoparticle
size can be changed within the limits of 1÷100 and more nanometers. The
polymer crystallites size makes up 10÷20 nm. The macromolecule can be
included in several crystallites, since at molecular weight of order of 6×10
4
its length makes up more than 400 nm. These reasoning's point out, that
macromolecular formations and polymer systems in virtue of their structure
features are always nanostructural systems.
However, in the cited above works the amorphous glassy polymers con-
sideration as natural composites (nanocomposites) is absent, although they
are one of the most important classes of polymeric materials. This gap rea-
son is quite enough, that is, polymers amorphous state quantitative model
absence. However, such model appearance lately [3-5] allows to consider
the amorphous glassy polymers (both linear and cross-linked ones) as natu-
ral nanocomposites, in which local order regions (clusters) are nanofiller and
surrounded them loosely packed matrix of amorphous polymers structure
is matrix of nanocomposite. Proceeding from the said above, in the present
chapter description of amorphous glassy polymers as natural nanocompos-
ites, their limiting characteristics determination and practical recommenda-
tion by the indicated polymers properties improvement will be given.
15.2
NATURAL NANOCOMPOSITES STRUCTURE
