Abstract
Recycled poly(ethylene terephthalate) (R-PET) was chain extended with pyromellitic dianhydride (PMDA) in a commercial size twin-screw reactive extrusion system. Temperature-modulated differential scanning calorimetry (TMDSC) was used to evaluate the effect of the chain extension process on the thermal transitions and crystallinity of R-PET. Reactive extruded recycled PET (RER-PET) samples were tested based on different PMDA concentration and reactive extrusion residence times. The glass transition temperature (T g) did not show a significant change as a function of PMDA addition or the extrusion residence time. Melting temperature (Tm) and crystallisation temperature (Tc) decreased with increasing PMDA concentration and with increasing extrusion residence time. RER-PET samples showed double melting peaks, it is believed that different melting mechanism is the reason behind this phenomenon. The crystallinity of RER-PET samples is lower than that of R-PET. RER-PET samples at constant PMDA concentration showed a decrease in crystallinity with increasing extrusion residence time. Results suggest that the reactive extrusion process is more dependent on PMDA concentration rather than reactive extrusion process residence time.
| Original language | English |
|---|---|
| Pages (from-to) | 865-884 |
| Number of pages | 20 |
| Journal | Journal of Thermal Analysis and Calorimetry |
| Volume | 78 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2004 |
| Externally published | Yes |
Keywords
- Chain extension
- Crystallinity
- Reactive extrusion
- Recycled pet
- TMDSC
