Conductive Thermoplastic Starch (TPS) Composite Filled with Waste Iron Filings

Danilo Battistelli,Raul Fangueiro,Carlo Santulli,Sofia Costa,Diana P. Ferreira

doi:10.28991/esj-2020-01218

Danilo Battistelli, Raul Fangueiro + Show 3 more

Open Access

https://doi.org/10.28991/esj-2020-01218

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Abstract

A thermoplastic starch (TPS) was produced, starting with potato starch, glycerol and acetic acid, to shape it in films of thickness around 100 microns. To TPS iron waste filing particles, in the amount of 12% the weight of starch, were introduced in different modalities: as received, reduced in size by the use of a mortar, after treatment with hydrochloric acid, and after treatment and removal of hydrochloric acid. Morphological studies were carried out by optical and scanning electron microscopy and illustrated that the dispersion of iron filings was not optimal, though some improvement was observed by a reduced dimension of the particles. Tensile tests indicated the considerable improvement of stiffness offered by the insertion of iron particles to TPS, although the ultimate strain was reduced to less than 10%. Thermal characterization using thermogravimetry allowed revealing the three typical peaks for potato starch degradation, with only a slight decrease due to iron introduction. EDS allowed evaluating the presence of impurities in the iron filings and evidenced that the presence of iron was more effective on the surface than in the rest of the film. As a final consideration, An improvement in electrical conductivity by over an order of magnitude was obtained by the TPS+Fe+HCl film with respect to pure TPS.

Highlights

Scrap iron, in the form of filings of random size and geometry, though prevalently powder, is a copious waste in blacksmith operations
The use of scrap iron powder as material filler faces some difficulties in environments, such as small blacksmith workshops, technical schools, etc.: here, it is normally disposed of as a special waste, even involving some costs, while on the other side re-using it in new materials might represent an opportunity
The presence and the dispersion of Fe particles into thermoplastic starch (TPS) films was evaluated by optical microscopy

Summary

1- Introduction

In the form of filings of random size and geometry, though prevalently powder, is a copious waste in blacksmith operations. The use of scrap iron powder as material filler faces some difficulties in environments, such as small blacksmith workshops, technical schools, etc.: here, it is normally disposed of as a special waste, even involving some costs, while on the other side re-using it in new materials might represent an opportunity. Preliminary work has demonstrated that by introducing unfiltered iron scrap powder in the production of a thermoplastic starch, based on corn starch, glycerol and acetic acid, carrying out moulding of the material on a glass support with the introduction of 0.8 wt.% of waste, sufficient tensile resistance was obtained [14]. The present work is aimed at solving these two problems, contamination and dimensional control of the filler, coming as far as to the assessment of electrical conductivity, which had not been measured before

2- Materials and Methods

3- Results and Discussion

4- Conclusion

5- Conflict of Interest

6- References