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Block copolymers of poly(l-lactide) and poly(e-caprolactone) or poly(ethylene glycol) prepared by reactive extrusion
| Content Provider | Semantic Scholar |
|---|---|
| Author | Stevels, Willem Marinus Bernard, Aurélie Witte, Peter Van De Dijkstra, Pieter J. Feijen, Jan |
| Copyright Year | 1996 |
| Abstract | Blends of poly(L-lactide) (PLLA) and poly(-caprolactone) (PCL) were prepared in a co-rotating twin screw miniextruder (40 rpm, 200°). It was attempted to prepare multiblock copolymers by allowing a controlled number of transesterification reactions. Various cat-alysts (n-Bu3SnOMe, Sn(Oct)2, Ti(OBu)4, Y(Oct)3, para-toluene sulphonic acid) were introduced to promote these transesterification reactions. However, PLLA degradation by ring-closing depolymerization was the dominant reaction in every case. Alternatively, after showing that L-lactide can be conveniently polymerized in the extruder, L-lactide and hy-droxyl functionalized prepolymers of PCL or poly(ethylene glycol) (PEG) were fed to the extruder in the presence of stannous octoate. Monomer conversions of over 90% and effective transformation of all hydroxyl end groups present were generally reached. Di-and triblock copolymers could be prepared in this way with characteristics very similar to polymers prepared in a batch-type process, but with considerably reduced reaction times in a fashion, which is, in principle, scaleable to a continuous process for the production of such block copolymers. |
| Starting Page | 1295 |
| Ending Page | 1301 |
| Page Count | 7 |
| File Format | PDF HTM / HTML |
| Volume Number | 62 |
| Alternate Webpage(s) | http://doc.utwente.nl/71284/1/Stevels96block.pdf |
| Alternate Webpage(s) | https://doi.org/10.1002/%28SICI%291097-4628%2819961121%2962%3A8%3C1295%3A%3AAID-APP20%3E3.0.CO%3B2-5 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
