Rheology of thermoplastic starch: Effects of temperature, moisture content, and additives on melt viscosity
| Autor: | C. L. Swanson, B. K. Jasberg, Julious L. Willett |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
chemistry.chemical_classification
Thermoplastic Materials science Polymers and Plastics Starch food and beverages General Chemistry Pelletizing Low-density polyethylene chemistry.chemical_compound chemistry Rheology Glycerol monostearate Materials Chemistry Composite material Water content Melt flow index |
| Zdroj: | Polymer Engineering and Science. 35:202-210 |
| ISSN: | 1548-2634 0032-3888 |
| DOI: | 10.1002/pen.760350214 |
| Popis: | The melt viscosity of thermoplastic starch has been investigated as a function of temperature, moisture content, and processing conditions. The effects of various low molecular weight additives have also been studied. Starch melts exhibit power law behavior over the range of shear rates studied. Melt viscosity decreased with increasing temperature and moisture content (MC). The power law index m increased with increasing temperature. The consistency K decreased with increasing temperature and increasing moisture content. Moisture content during the pelletizing step influenced melt viscosities measured after equilibration to different MCs. All additives studied except glycerol monostearate (GMS) significantly lowered the melt viscosity of starch, some more effectively than water relative to starch with 15% MC. Starch with GMS had viscosities essentially the same as, or slightly higher than, starch/water. This behavior may be due to the presence of unmelted helical inclusion complexes of starch and GMS. Starch formulations at 160 o C exhibited melt viscosities similar to an LDPE of melt index 1.8 |
| Databáze: | OpenAIRE |
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