properties). With regard to the properties of the phases making up the composite
hydrogel, then one of them must be a polymeric hydrogel, and it may be either a
synthetic or natural polymer. The second phase may also be a polymeric
hydrogel of synthetic or natural origin, but may be even hydrophobic polymer
and an inorganic substance. In line with the classification of separating
composite hydrogels into groups:
1. Hydrogels consisting of two hydrophilic polymers each of which is
capable of forming individual polymer hydrogel;
2. A hydrogel comprising hydrophilic and hydrophobic polymers;
3. A polymer hydrogel comprising an inorganic phase.
Other characteristics (morphology and size of the structural elements, the
nature of the interfacial interactions getters and methods of combining two
phases) are also important, but can not be the basis for classification, as they
relate to each group of materials listed above. Questions morphology of
composite hydrogels have already touched on. Changing the size of the
structural elements can lead to the creation of materials of the same components
with fundamentally different properties. The nature of the interactions between
the components. It is caused by covalent bonds in the block - and graft
copolymers. This interpolymer complexes are formed due to the formation of
hydrogen bonds, donor - acceptor, ionic and hydrophobic interactions of
functional groups, the engagement of macromolecular chains of interpenetrating
and semi-interpenetrating polymer networks. These interfacial interactions are
directly related to the production methods of composite polymeric hydrogels: the
combination of polymers in solution and subsequent formation of the physical or
chemical bonds between polymers joint simultaneous or sequential synthesis of
polymers, accompanied by phase separation. Technological realization of each
of these options is varied and are discussed below. As discussed in the review
system, which is used in the form of a hydrogel containing water. This
circumstance was pointed out in connection with the fact that the dried hydrogels
in biphasic form films and coatings are described in the scientific literature, but
constitute a separate group of polymeric materials.
Composite polymeric hydrogels based on hydrophilic polymers are
well
known,nowadays. The presence of polar groups of ionic and non-ionic
polymers in hydrophilic nature helps to reconcile them in solutions without
significant energy costs, due to the formation of intermolecular hydrogen bonds
and ionic bonds. With an appropriate choice of functional groups and conditions
combining covalent bonds may occur in composite hydrogels. The hydrogels
constructed by type of interpenetrating and semi-interpenetrating polymer
networks, intermolecular engagement, complemented by physical interactions of
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