Starch and cellulose nanocrystals together into thermoplastic starch bionanocomposites. (6th March 2015)

• Record Type: Journal Article
• Authors: González, Kizkitza; Retegi, Aloña; González, Alba; Eceiza, Arantxa; Gabilondo, Nagore
• Is Part Of: Carbohydrate polymers. Volume 117(2015)
• Page Start: 83
• Page End: 90
• Publication Date: 2015-03-06
• Subjects: Bionanocomposite -- Thermoplastic starch -- Polysaccharide nanocrystals -- Morphology -- Thermal, mechanical and barrier properties; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2014.09.055
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Bioanocomposites were reinforced with combined polysaccharide nanocrystals. Increasing waxy starch nanocrystals content mechanical properties were enhanced. An important improvement of oxygen permeance was obtained at certain percentages. Barrier to water vapour was maintained almost insensitive to nanoreinforcement. Mechanical properties were improved by the incorporation of cellulose nanocrystals. Abstract: In the present work, thermoplastic maize starch based bionanocomposites were prepared as transparent films, plasticized with 35% of glycerol and reinforced with both waxy starch (WSNC) and cellulose nanocrystals (CNC), previously extracted by acidic hydrolysis. The influence of the nanofiller content was evaluated at 1 wt.%, 2.5 wt.% and 5 wt.% of WSNC. The effect of adding the two different nanoparticles at 1 wt.% was also investigated. As determined by tensile measurements, mechanical properties were improved at any composition of WSNC. Water vapour permeance values maintained constant, whereas barrier properties to oxygen reduced in a 70%, indicating the effectiveness of hydrogen bonding at the interphase. The use of CNC or CNC and WSNC upgraded mechanical results, but no significant differences in barrier properties were obtained. A homogeneous distribution of the nanofillers was demonstrated by atomic force microscopy, and a shift of the two relaxation peaks to higher temperatures was detected by dynamic mechanical analysis.