Page 29 - Polymer-based Nanocomposites for Energy and Environmental Applications

8 Polymer-based Nanocomposites for Energy and Environmental Applications

resins, and its selection depends on the required physical and chemical characteristics.
The curing agents are as follows:
(A) Aliphatic amines (e.g., triethylenetetramine (TETA) and diethylenetriamine (DETA))
(B) Aromatic amines (e.g., diaminodiphenylsulfone (DDS) and dimethylaniline (DMA))
(C) Anhydrides (e.g., phthalic anhydride and nadic methyl anhydride (NMA))
(D) Amine/phenol formaldehydes (e.g., urea formaldehyde and melamine formaldehyde)
(E) Catalytic curing agents (e.g., tertiary amines and boron trifluoride complexes)
Through the application of epoxy matrices, Koo et al. [41] introduced a technique
of molecular dynamics (MD) simulation to show brittle fracture in epoxy-based
thermosetting polymer under mechanical loading. The simulation results that
illustrated the brittle fracture can be controlled via the covalent bond dissociation with
high computational efficiency. In another work [42], epoxy-copolysilsesquioxane
nanocomposites containing multiwalled carbon nanotubes (MWCNT) were
synthesized. Also, Gonc¸alvesa et al. [43] studied the mechanical properties including
compression, flexion, and hardness factors of a composite produced from the mixing
of granitic stone powder and epoxy resin.

1.2.3.6 Polyelectrolyte matrixes

Polyelectrolytes include a net positive or negative charge around the neutral pH.
Generally, these polymers are water-soluble, in which this solubility is preceded by
the electrostatic interactions among water and the charged monomer. In this field, cer-
tain derivatives of cellulose polymers, DNA, protein, and carrageenan are introduced
as polyelectrolytes. The polyelectrolytes are categorized as synthetic polyelectrolytes,
chemically modified biopolymers, and also natural polyelectrolytes.
Also, they are

(A) homopolymers and copolymers on the basis of their composition;
(B) linear, branched, and cross-linked due to their molecular architecture;
(C) polyacids/polyanions, polybases/polycations, and polyampholytes based on their
electrochemistry [44].
Researchers [45] evaluated the probability of applying mixtures and/or polyelectro-
lyte complexes from both chitosan-alginate and chitosan-carrageenan as drug release
systems. Also, Glinel et al. [46] illustrated the developments of responsive multilayers
generated by layer-by-layer assembly of oppositely charged polymers, with particular
focus on the preparation of sensitive systems against the temperature and pH change.

1.2.3.7 Rubber matrixes

Rubbers-elastomers are characterized by their abilities in reversible deformation
under the external deformation loads. This deformation is regarding to molar mass,
structure of rubbers, and external condition of deformation. In this process, elastic
and/or hyperelastic deformation achieves from the ability of rubber macromolecules
to provide an organized state under the influence of deforming forces with no defor-
mation of either chemical bonds of polymer chain atoms or their valence angles.