Research Article
XRD Investigation of Some Thermal Degraded
Starch Based Materials
Mihai Todica,
1
Elena Mihaela Nagy,
2
Carmen Niculaescu,
1
Oana Stan,
1
Nicolae Cioica,
2
and Cornel Viorel Pop
1
1
Faculty of Physics, Babes-Bolyai University, Nr. 1, Kogalniceanu Str., 40047 Cluj-Napoca, Romania
2
INMA Bucharest, Branch Cluj-Napoca, Nr. 59, Al. Vaida Voievod Str., 40047 Cluj-Napoca, Romania
Correspondence should be addressed to Mihai Todica; mihai.todica@phys.ubbcluj.ro
Received 17 August 2016; Revised 24 October 2016; Accepted 10 November 2016
Academic Editor: Nikˇ sa Krstulovi´ c
Copyright © 2016 Mihai Todica et al. Tis is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Te thermal degradation of some starch based materials was investigated using XRD method. Te samples were obtained by thermal
extrusion of mixtures of diferent proportions of starch, glycerol, and water. Such materials are suitable for the manufacturing of
low pollutant packaging. Termal degradation is one of the simplest ways to destroy such materials and this process is followed by
structural modifcation of the local ordering of samples, water evaporation, crystallization, oxidation, or destruction of the chemical
bonds. Tese modifcations need to be studied in order to reduce to the minimum production of pollutant residues by burning
process. XRD measurements show modifcation of the local ordering of the starch molecules depending on the temperature and
initial composition of the samples. Te molecular ordering perturbation is more pronounced in samples with low content of starch.
1. Introduction
Te recycling or disposal without pollutant efects of the
enormous quantity of residual waste produced daily by the
humanity is one of the major challenges of today. One of the
solutions is to use biodegradable materials in manufacturing
these products [1, 2]. Wood or cellulose could be suitable
materials for this purpose, but their use on an industrial scale
leads to excessive exploitation of the forests, with negative
efects on climate and environment. On the other hand, the
destruction of these materials by burning or putrefaction
is pollutant. A viable alternative is the use of regenerative
materials obtained from crops or other plants with low
pollution potential. Starch is one of the most promising
materials for this purpose, because it can be easily obtained
at low cost from corn, potatoes, or other vegetables and can
be fully recycled without any toxic residues [3–5]. However,
starch in its natural state has low mechanical properties and
low resistance to water and cannot be used for packaging.
Improvement of its qualities can be achieved by combination
with glycerol, which acts as a plasticizer. Previously, we
obtained new materials by thermal extrusion of diferent
proportions of water, starch, and glycerol [6, 7]. Te samples
obtained this way are less soluble in water and have enhanced
mechanical properties compared with the initial component.
Rheological investigation of these samples show specifc fow
behavior depending on shear stress and temperature [8]. On a
microscopic scale, the NMR investigations indicate diferent
mechanisms of relaxation of the transversal magnetization of
the protons depending on temperature and sample compo-
sition. Tese fndings were correlated with the new physical
structures and local molecular organization induced by the
synthesis process [9].
Te starch and the pure glycerol, in their initial state, can
be easily recycled without pollutant efects by hydration or
moderate heating, but the product obtained through the plas-
ticizing process has diferent physical properties compared
with the initial components and exhibits diferent behavior
in the presence of water or when submitted to thermal
degradation. Heating is one of the easier ways to destroy the
used packaging, but this oxidative process leads to important
modifcation of the physical and chemical properties of the
materials. Depending on the temperature and duration of the
heating we can assist to modifcation of the organization of
Hindawi Publishing Corporation
Journal of Spectroscopy
Volume 2016, Article ID 9605312, 6 pages
http://dx.doi.org/10.1155/2016/9605312