Synthesis of polyvinyl alcohol/modified starch-based biodegradable nanocomposite films reinforced with starch nanocrystals for packaging applications

Abstract

In the present work, corn starch was grafted with oleic acid in the presence of redox initiators. Starch nanocrystals (SNCs) were synthesized using acid hydrolysis method and nanocomposite films were prepared by incorporation of SNCs into polyvinyl alcohol/starch (PVA/S) and PVA/grafted starch (PVA/GS) matrix, separately. It was observed that SNCs exhibited a platelet-like shape and in the size range of 200 nm. The increased crystallinity of SNCs indicated the removal of the amorphous and waxy region after acid hydrolysis of starch. Scanning electron micrographs of nanocomposite films showed good dispersion of SNCs within the PVA/GS matrix compared to the PVA/S matrix. The tensile strength of the nanocomposite films increased significantly with the reinforcement of SNCs into PVA/S matrix. Water uptake (%) of PVA/GS nanocomposite film decreased by 38.25% compared to the PVA/S nanocomposite film. Reinforcement of SNCs with PVA/S matrix improved the biodegradability of the films and was higher than PVA/S film. PVA/S nanocomposite film showed 32.4% weight loss after 120 days of soil burial degradation test. Thus, the obtained nanocomposite films can provide a potential alternative to the synthetic and nondegradable packaging films used worldwide.

Development of Starch-Based Materials Using Current Modification Techniques and Their Applications: A Review

“…Packaging Crosslinking Cross-linked-TPS [116] Cross-linked starch [117] Cross-linked films of quaternary ammonium modified starch and Polyvinyl alcohol [137] Grafting PVA (Polyvinyl alcohol)/starch and cellulosic material barley husk (BH) [117] Grafting Polyvinyl alcohol/modifiedstarch-based biodegradablenanocomposite films [138] Oxidation 7-Hydroxy-4-methylcoumarin doped Polyvinyl alcohol/oxidized maize starch [119] Corn starch oxidation was performed using sodium periodate [118] Dual Modification Etherified-oxidized cassavastarch/Polyvinyl alcohol blends [139] Bio-based adhesives Crosslinking Cassava starch, citric acid and Polycarboxylic acid. [120] Grafting Corn starch-g-poly (vinyl acetate-co-butyl acrylate) [121] Starch-g-polyvinyl alcohol [122] Pharmaceutical Industries Etherification Anionic carboxymethyl and cationic carboxymethyl [140] Carboxymethyl starch [141] Carboxymethyl starch [123] Carboxymethyl starch [124] Carboxymethyl corn starch [126] Acetylation Acetylated starch nano-crystals [142] Crosslinking Starch coated iron oxide nanoparticles [143] Grafting Fe 3 O 4 /starch-g-polyester nanocomposite [144] Cellulose nanofiber-assisted starch graft-Polyacrylic acid [145] Esterification Octenyl succinic anhydride modified starch [125] Table 5.…”

Effect of Physical Pretreatments on the Hydrolysis Kinetic, Structural, and Thermal Properties of Pinhão Starch Nanocrystals

“…[34,37] ANN did not promote changes in the pinhão RC, while HMT and SNT as pretreatment decreased it (Table 2). High RC of the starches usually results in highly crystalline SNC, which is expected for some applications, such as reinforcement at composite films and packaging, [13][14][15][16][17] or even for carbon black and silica replacement on tires. [9] It improves the barriers, thermal, and mechanical properties of the reinforced materials.…”

“…[1] The starch films and biodegradable packaging. [13][14][15][16] Other reports describe SNC composites with decreased water vapor permeability (WVP), increased thermal stability, and enhanced mechanical properties. [5,[17][18][19] The addition of 5% (w/w) of mango kernel SNC in starch films increases their tensile strength (about 90%) and modulus (about 120%), and reduces the water vapor permeability (WVP) by approximately 15%.…”

“…Reinforcement by SNCs improved the biodegradability of the films, showing 32.4% weight loss after 120 days of soil burial degradation test. [16] The development of a rapid and efficient approach to produce nanocrystals from starch, through speeding up the hydrolysis rate in the first stage, is essential to enable it viable to commercial application. [6,20] The physical ultrasound assisted methods are often used to prepare SNCs.…”

Radiation Modification and Characterization of Polyvinyl alchohol/Starch/Citric Acid/Glycerol Bioblend Film

“…The petroleum used synthetic polymers and its adverse effects of environmental pollution due to its limitation of recyclability and non biodegradability, promote many research on synthesis of new biodegradable renewable sources alternatives such as starch, cellulose, protein, chitin, etc due to their biodegradation and have been considered as alternatives for the nonbiodegradable petroleum based polymers [1][2][3][4][5][6][7][8][9][10][11].…”