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Extruded/injection‐molded composites containing unripe plantain flour, ethylene–vinyl alcohol, and glycerol: Evaluation of mechanical property, storage conditions, biodegradability, and color
Author(s) -
Vargas Apolonio,
Berrios Jose De J.,
Chiou BorSen,
Wood Delilah,
Bello Luis A.,
Glenn Gregory M.,
Imam Syed H.
Publication year - 2011
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.35271
Subject(s) - materials science , ultimate tensile strength , vinyl alcohol , composite material , glycerol , composite number , dynamic mechanical analysis , relative humidity , starch , elongation , scanning electron microscope , chemistry , food science , polymer , organic chemistry , physics , thermodynamics
Extruded/injection‐molded composites of excellent mechanical property were produced from plantain flour (PF) blended with ethylene–vinyl alcohol (EVA) and glycerol. Scanning electron microscopy (SEM) revealed that composites had a smooth surface, indicative of an excellent compatibility between PF, EVA, and glycerol. Generally, tensile strength (TS), elongation at break (%E), and the displacement (DM), all decreased with increased PF content in the composite accompanied by an increase in Young's modulus ( M ). The composites with higher PF contents (60% or higher) had more stable mechanical properties. Selected composites (60% PF content) stored at −20°C and 4°C for 40 h showed only minor changes in mechanical properties compared with controls (23°C). However, samples stored for a similar period at 80°C were drastically altered in their mechanical properties resulting in huge increases in TS and M and a 10‐fold decrease in the %E. Samples prestored at various relative humidities (RHs) for 40 h exhibited only slight decrease in TS and M and a concomitant increase in the %E with increased RH. Interestingly, sample prestored at both −20°C and 80°C exhibited significantly higher rates and extents of degradation. SEM analysis of samples left in compost for 8 weeks showed a rapid surface erosion and material deterioration with time. Evaluation of the color produced during heat processing of starch in PF as a result of Maillard reaction showed an increase in the values of luminosity ( L *), chroma ( C *), and hue angle ( h *) with decreased PF content in the composite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012