POLYMERIC COMPOSITE MATERIALS FROM COAL

Coal is a complex macromolecule/polymeric (if sulfur & nitrogen is not taken in
consideration for monomer units) organic rich component, but cannot be used as polymer.
Although free electron are available on the surface of the coal but it does not behave like
conducting polymer or temperature sensor. Importance of high performance engineering
plastics is increasing day by day. The monomer for this is being synthesized in about 16 steps
from single aromatic system/compound. Coal can yield monomer in a single step by its
degradation. Coal has to be suitably choiced for getting specific monomer.
Keywords: Coal; polymeric, Composite, Materials.
3N Nitric acid oxidation of coal introduces nitro groups besides degradation. The
solubilization of oxy coal in acetone enhanced due to the presence of nitro group. The acetone
soluble part of the coal contained carboxylic acid functional groups in large amount i.e.
12.6%. After its interaction with aniline, the percent carboxylic acid functional group
declined from 12.6% to 1.68%. Aniline interacted with carboxylic functional groups in two
steps, in the first step it formed anilide, and then carbonyl oxygen of anilide further interacted
with another molecule of aniline and formed a stable compound which is a composite material
and acts as conducting polymer. Thus for the first time conducting polymer from coal has
been prepared.
Oxidation of coal can reduce the complexity of coal by its degradation and can be
used in preparation of monomers,poly aromatic chemicals, organic conducting polymers,
organic temperature sensors etc. Studies are being done in the field of conducting polymers
such as poly aniline (PANI) and amine functional aniline acetaldehyde condensate (AAC) by
using pure compounds .The objective of the work is to replace metal based conductors (AAC)
by cheaper organic polymeric materials . Most of the researchers in different countries
carried out polymerization of aniline following the same protocol. Polyaniline (PANI) exists
in a variety of forms that differ in chemical and physical properties [1]. The most common
green protonated emeraldine has conductivity on a semiconductor level of the order of
100Scm-1, many orders of magnitude higher than that of common polymers(<10-9Scm-1 ) but
lower than that of typical metals(>104Scm-1 ).
EXPERIMENTALS:
Proximate and Ultimate analyses have been done by standard methods prescribed in BIS [7].
Estimation of functional groups like hydroxyl (-OH), carboxyl(-COOH),Carbon methyl have
been done as reported.(ref.8) 10g of Samla coal was taken in a flat bottom flask and to this
added 100 ml of 3N HNO3 solution for oxidation at refluxing temperature for 8 hours. After
completion of the reaction, the solution was filtered with excess of water till it is acid free. Now
the residual part of the treated coal i.e. oxy coal was extracted with acetone as per solvent
extraction procedure. Soluble and insoluble fractions of acetone extracted part were
characterized by proximate & ultimate analyses. Acetone soluble fraction of oxy coal was
treated with aniline for making polymeric adducts as follows. 1.0 gm acetone soluble fraction of
oxy coal and 30 ml of aniline were taken in a flat bottom conical flask in dry condition and then
refluxed for 10 hrs at 700C.