Brucite nanoplates reinforced starch bionanocomposites

• Published in: Carbohydrate polymers 2013-02, Vol.92 (2), p.1743-1751
• Main Authors: Moreira, Francys K.V., Pedro, Daniel C.A., Glenn, Gregory M., Marconcini, José M., Mattoso, Luiz H.C.
• Format: Article
• Language: English
• Subjects: Applied sciences; Biodegradable plastics; Bionanocomposites; Brucite nanoplates; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Glycerol - chemistry; Magnesium Hydroxide - chemistry; Mechanical Phenomena; Mechanical reinforcement; Models, Molecular; Molecular Conformation; Nanocomposites - chemistry; Nanoparticles - chemistry; Plastics - chemistry; Polymer industry, paints, wood; Starch; Starch - chemistry; Technology of polymers; Temperature
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2012.11.019

► Starch and brucite have attractive potential to develop bionanocomposites. ► Brucite nanoplates can interact with starch matrices though hydrogen bonding. ► Increasing brucite amount greatly increase mechanical properties of starch films. ► Brucite nanoplates could be effective to enhance the thermal stability of starch. ► Relationships between bionanocomposite property and brucite amount are reported. In this paper the mechanical reinforcement of nano-sized brucite, Mg(OH)2 in a series of bionanocomposite films based on starch was investigated. Brucite nanoplates with an aspect ratio of 9.25 were synthesized by wet precipitation and incorporated into starch matrices at different concentrations (0–7.5wt.%). Scanning electron microscopy revealed a high degree of nanoplate dispersion within the starch bionanocomposites and good interfacial adhesion between the filler and matrix. The brucite nanoplates formed agglomerates at high concentrations. The reinforcement factor values of the bionanocomposites were higher than the values predicted from the Halphin–Tsai model, which was attributed mainly to the high surface area of the nanoplates. Brucite (1wt.%) nearly doubled the elastic modulus of starch films. Thermogravimetric analyses indicated some interaction between starch and the brucite that modified their decomposition profiles. Mechanical tests of glycerol plasticized bionanocomposites showed that the reinforcing efficiency of brucite remained high even at 10wt.% and 20wt.% of plasticizer.