Effectiveness of thermo-compression for manufacturing native starch bulk materials
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In this study, thermo-compression molding was used to fabricate bulk materials from native starch powder. The objective was to determine the process parameters that enabled the welding of starch granules while preserving their crystallinity. The effects of forming parameters such as temperature, compression stress, and water content on the microstructural and mechanical properties of the starch samples were studied. For the optimal forming conditions, good compaction and cohesion of starch granules were obtained, while successfully preserving their native crystalline structure. The flexural Young’s modulus of the best samples reached an average value of 3 GPa and the flexural strength reached 10 MPa. However, these materials also exhibited unwanted cracks. The potential origin of these defects was associated to the heterogeneous distribution of water during processing as well as thermal shrinkage, moisture uptake, and viscoelastic recovery that occurred after the mold ejection.
KeywordsStarch Welding Compaction Compressive Stress Starch Granule
The authors gratefully acknowledge Institut Carnot PolyNat for funding this study. Besides, they would like to thank S. Rolland du Roscoat, P. Charrier, B. Khelifi, D. Curtil, R. Passas, C. Sillard, and S. Dufreney for their technical support, as well as R. Léger from Centre des Matériaux des Mines d’Alès (C2MA) at École des mines d’Alès for assistance with pycnometer experiments. The LGP2 and 3SR laboratories are part of LabEx Tec 21 (Investissements d’Avenir—Grant Agreement No. ANR-11-LABX-0030).
- 4.Ceseracciu L, Heredia-Guerrero JA, Dante S, Athanassiou A, Bayer IS (2015) Robust and biodegradable elastomers based on corn starch and polydimethylsiloxane (PDMS). ACS Appl Mater Interfaces 7:3742–3753Google Scholar
- 9.Biliaderis CG (2009) Structural transitions and related physical properties of starch. In: BeMiller J, Whistler R (eds) Starch—chemistry and technology. Academic Press, Thessaloniki, pp 293–372Google Scholar
- 11.Fayolle B, Verdu J (2005) Vieillissement Physique des Matériaux Polymères, Techniques de l’Ingénieur Propriétés Générales des Plastiques AM3150:1–19Google Scholar
- 14.Millauer C, Rosa G, Schär R (1987) Determination of the density of starches and cereal products as a function of temperature and pressure. In: Meuser F, Manners DJ, Seibel W (eds) Plant polymeric carbohydrates. Woodhead Publishing, Cambridge, pp 86–103Google Scholar