Abstract
The rheological properties of thermoplastic starch (TPS) melt were investigated using the new multipass rheometer (MPR). This rheometer consists of two servo-hydraulically driven pistons and a fully closed barrel, enabling pressurisation of sample and preventing moisture loss during the process. The starch samples (with different plasticiser contents, 70-110%, and at different glycerol/water ratio, 1:4, 2:3, and 3:2) were first well transformed into TPS in MPR and then tested at different temperatures (90, 110 and 130 °C). The TPS behaved as a shear-thinning material, and the power-law model was used to describe its rheological behaviour. The combination of glycerol and water had the greatest influence on the power-law index n while temperature had little influence. By mastercurve study, it was shown that the higher the glycerol/water ratio, the stronger the shear-thinning behaviour was. This was explained by interaction between starch and plasticiser and different structural characteristics at different conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 914-919 |
| Number of pages | 6 |
| Journal | Carbohydrate Polymers |
| Volume | 83 |
| Issue number | 2 |
| Early online date | 8 Sept 2010 |
| DOIs | |
| Publication status | Published - 10 Jan 2011 |
Keywords
- Capillary rheometry
- Multipass rheometer
- Rheology
- Shear-thinning
- Thermoplastic starch
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry