Microcellular extrusion foaming of poly(lactide)/poly(butylene adipate-co-terephthalate) blends
β Scribed by Srikanth Pilla; Seong G. Kim; George K. Auer; Shaoqin Gong; Chul B. Park
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 645 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0928-4931
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β¦ Synopsis
Foamed poly(lactide) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends were processed via the microcellular extrusion process using CO as a blowing agent. Talc has been added to promote heterogeneous nucleation. Two types of PLA/PBAT blend systems were investigated: Ecovio, which is a commercially available compatibilized PLA/PBAT blend; and a non-compatibilized PLA/PBAT blend at the same PLA/PBAT ratio (i.e., 45:55 by weight percent). Six different formulations were investigated: pure PLA, PLA-talc, Ecovio, Ecovio-talc, non-compatibilized PLA/PBAT blend, and non-compatibilized PLA/PBAT-talc. The effects of various processing parameters such as die temperature, talc and compatibilization on various foaming properties such as cell morphology, volume expansion ratio (VER), open cell content (OCC) and crystallinity were investigated. As per the DSC thermograms, it was observed that compatibilization has merged the two distinctive melting peaks of PLA and PBAT into a single peak while lowering the peak temperature. In general, the addition of talc has decreased the average cell size and VER and increased the cell density and crystallinity; however, it has varying effects on the open cell content. Compatibilization has reduced the average cell size and volume expansion but increased the cell density and had varying and no effects on the OCC and crystallinity, respectively. Similar to compatibilization, the die temperature was found to have varying and no effects on the OCC and crystallinity, respectively. Except for PLA and non-compatibilized PLA/PBAT blend, the cell size and VER of all other formulations did not vary much throughout the entire temperature range (130-150Β°C). The cell density was found to be insensitive to die temperatures except for Ecovio and Ecovio-talc.
π SIMILAR VOLUMES
Characterization of poly(butylene adipate-co-succinate) (PBAS)/poly(butylene terephthalate) (PBT) copolyesters resulting from the intermolecular ester-exchange reaction between molten PBAS and PBT have been analyzed using 1 H-NMR spectroscopy, differential scanning calorimetry, wide-angle X-ray diff
## Abstract Blends of poly(Lβlactic acid) (PLLA) and poly (butylene terephthalateβ__co__βadipate) (PBTA) were prepared at ratios of 50 : 50, 60 : 40, and 80 : 20 by melt blending in a Laboplastomill. Improved mechanical properties were observed in PLLA when it was blended with PBTA, a biodegradable