Abstract

This study presents experimental investigation on synthesis of conducting polymer films made from cassava starch with the purpose of evaluating the influence of pH on some mechanical and physicochemical properties. Starch increases the mechanical integrity in biodegradable conductor polymers used like sensors, but there are some others potential factors influencing mechanical properties like plasticizers, additives and process conditions. No previous works report the quantitative effect of pH on mechanical properties of cassava starch’s film. Glycerol, glutaraldehyde and polyethylenglycol were used as plasticizers. To obtain acid and basic films, pH was modified by HCl and NaOH. Seven different pH levels were reached, in order to evaluate tensile strength, ductility and elastic module. Tensile tests were developed according to the ASTM D638 norm. Clear influence of pH in these mechanical properties was found; which is shown through a regression that relates ductility with a pH input. This research concludes that is possible to modify the mechanical strength or flexibility of the films by changing pH, which is in general terms a practical process. Acid films have a higher elastic module (50-70 MPa) than polymers with basic pH (15-25 MPa). Basic films’ deformation shows higher values than acid films; the first ones reach 0.95 mm/mm of deformation and the second ones have average values of 0.3 mm/mm.

Keywords:

Cassava starch, ductility, elastic module, pH, tensile strength,

References

1. Arrieta, Á.A., M.L. Rodríguez-Méndez and J.A. De Saja, 2010. Aplicación de una lengua electrónica voltamétrica para la clasificación de vinos y estudio de correlación con la caracterización química y sensorial. Quim. Nova, 33(4): 787-793.
   CrossRef    
2. Almario, Á.A., A.J. Mu-oz and M.P. Luna, 2015. Películas conductoras de almidón de yuca (cassava) como material para un acumulador electroquímico de carga (batería). Rev. Soc. Quím. Perú, 81(4): 328-338.
   Direct Link
3. Arrieta, A. and A. Jaramillo, 2014. Bioplásticos eléctricamente conductores de almidón de yuca. Rev. Colomb. Mater., 5: 42-49.
   Direct Link
4. Arrieta, A.A., P.F. Ga-an, S.E. Márquez and R. Zuluaga, 2011. Electrically conductive bioplastics from cassava starch. J. Braz. Chem. Soc., 22(6): 1170-1176.
   CrossRef    
5. De Aquino, A.B., A.F. Blank and L.C.L.D.A. Santana, 2015. Impact of edible chitosan–cassava starch coatings enriched with Lippia gracilis Schauer genotype mixtures on the shelf life of guavas (Psidium guajava L.) during storage at room temperature. Food Chem., 171: 108-116.
   CrossRef    PMid:25308649    
6. Deep, A., A.L. Sharma, P. Kumar and L.M. Bharadwaj, 2012. Nanostructured polyaniline-silicon substrate for protein biosensing. Sensor. Actuat. B-Chem., 171-172: 210-215.
   Direct Link
7. Pircher, N., S. Veigel, N. Aigner, J.M. Nedelec, T. Rosenau and F. Liebner, 2014. Reinforcement of bacterial cellulose aerogels with biocompatible polymers. Carbohyd. Polym., 111: 505-513.
   CrossRef    PMid:25037381 PMCid:PMC4118683    
8. Quiroga, R.M. and W.V. Díaz, 2011. Metodología para la caracterización termo-mecánica de películas plásticas biodegradables. Prospect, 9(1): 46-51.
   Direct Link
9. Singh, J. and S. Gu, 2010. Commercialization potential of microalgae for biofuels production. Renew. Sust. Energ. Rev., 14(9): 2596-2610.
   CrossRef    
10. Tsai, B.H., C.J. Chang and C.H. Chang, 2016. Elucidating the consumption and co2 emissions of fossil fuels and low-carbon energy in the united states using lotka–volterra models. Energy, 100: 416-424.
    CrossRef    
11. Venugopal, V., H. Zhang, R. Northcutt and V.B. Sundaresan, 2014. A thermodynamic chemomechanical constitutive model for conducting polymers. Sensor. Actuat. B-Chem., 201: 293-299.
    Direct Link

Competing interests

The authors have no competing interests.

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The authors have no competing interests.