Mechanical and barrier properties of composite films based on rice flour and cellulose fibers

Abstract

a b s t r a c tRice flour is a low-cost starchy material, produced from rice that is broken during processing. Rice flourbased films have promising application on food packaging, because of their environmental appeal and low cost. Nevertheless, their mechanical and moisture barrier properties should be improved. The aim of this study was to develop biodegradable films based on rice flour and enhance their properties by reinforcing them with cellulose fibers. In this way, rice flour films with and without fibers were prepared by casting, with glycerol or sorbitol as plasticizer. Their physicochemical, microscopic and mechanical properties were studied. SEM analysis of films revealed compact structures. Films prepared with fibers presented lower water vapor permeabilities if compared with films without fibers. Films containing sorbitol were less permeable to water and more rigid. The incorporation of fibers reinforced mechanically the flour-based films, which presented higher tensile strength, but did not influence their deformation capacity. Therefore, preparing biodegradable films from rice flour is a new alternative of using this raw material. The use of cellulose fibers as reinforcing agent is a viable alternative to improve the properties of rice flour-based films, because they are biodegradable and available at low cost.

Effect of Sugar Palm-derived Cellulose Reinforcement on the Mechanical and Water Barrier Properties of Sugar Palm Starch Biocomposite Films

“…This observed tensile behavior can be attributed to the favorable interaction between the SPC and SPS matrices, which facilitated adequate interfacial adhesion because of their chemical similarities. Similar results were reported by other authors (Dias et al 2011;Pereda et al 2011). In addition, contrary to the increase in tensile strength and tensile modulus, the elongation at break for the composite films decreased from 40.99 to 32.8% as the SPC concentration increased from 1 to 10 wt.% in the neat SPS films.…”

“…The micrograph of the virgin SPS films showed a smooth and continuous surface with no trace of starch granular or cracks. Similar observations were reported by Sanyang et al (2016) and Dias et al (2011) for neat sugar palm starch and rice flour films, respectively. On the other hand, the addition of 10 wt.% SPC to a virgin SPS film (SPS-C10) displayed an even, random distribution of SPC within the SPS matrix, without pores or cracks.…”

“…Such drawbacks strongly limit their wide application, especially for food packaging purposes. Many studies have been undertaken by material scientists to improve the mechanical properties and enhance the water sensitivity of starchbased materials without compromising their biodegradability (Sanchez-Garcia et al 2008;Müller et al 2009;Dias et al 2011). The addition of natural cellulose fibers during the preparation of starch composite films is an effective strategy for improving the functional properties of packaging films, as documented by various researchers (Teixeira et al 2009;Teac et al 2013;Slavutsky and Bertuzzi 2014).…”

“…Cellulose fibers utilized as reinforcement have been shown to enhance the performance of starch composite films by providing high thermal stability and good mechanical properties such as high tensile strength and high Young's modulus (Kaushik et al 2010;Savadekar and Mhaske 2012). Furthermore, the addition of cellulose fibers has been reported to decrease the water vapor permeability of starch-based films (Müller et al 2009;Dias et al 2011), thus increasing their suitability for food packaging applications.…”

Sugar palm nanocrystalline cellulose reinforced sugar palm starch composite: Degradation and water-barrier properties

“…Besides, these biopolymer also has been explored widely for the potential manufacture of products such as food and fruit packaging films, plastic shopping bags, flushable linter, medical delivery system and device [2,4]. Nevertheless, the utilization of starch polymer as a films have been reported to have low water barrier properties [5][6] . Thus, many studies have been conducted to improve the water sensitivity of starchbased materials without negotiating their biodegradability [7][8][9].…”