Polymerization of l-lactide with SnCl2: A Low Toxic and Eco-friendly Catalyst
Polymerizations of l -lactide catalyzed either by neat SnCl 2 or by SnCl 2 + difunctional cocatalysts were conducted in bulk at 180, 160 and 140 °C with variation of the Lac/Cat ratio and time. With neat SnCl 2 poly(L-lactide) having weight average molecular weights (uncorrected M w ’s) up to 190 0...
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Published in: | Journal of polymers and the environment Vol. 29; no. 8; pp. 2504 - 2516 |
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Main Authors: | , |
Format: | Journal Article |
Language: | English |
Published: |
New York
Springer US
01-08-2021
Springer Nature B.V |
Subjects: | |
Online Access: | Get full text |
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Summary: | Polymerizations of
l
-lactide catalyzed either by neat SnCl
2
or by SnCl
2
+ difunctional cocatalysts were conducted in bulk at 180, 160 and 140 °C with variation of the Lac/Cat ratio and time. With neat SnCl
2
poly(L-lactide) having weight average molecular weights (uncorrected M
w
’s) up to 190 000 g mol
−1
were obtained mainly consisting of linear chains. Addition of salicylic acid or 1,1-bisphenol yielded a higher fraction of cyclic polylactides but lower molecular weights. Furthermore, SnCl
2
was compared with Bu
2
SnCl
2
and various other metal chlorides and the best results were obtained with SnCl
2
. With ethyl L-lactate as initiator SnCl
2
-catalyzed ROPs were performed at 120 °C and the lac/initiator ratio was varied. All these experiments were conducted under conditions allowing for comparison with ROPs catalyzed with neat Sn(II)-2-ethyhexanoate. Such a comparison was also performed with ε-caprolactone as monomer. |
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ISSN: | 1566-2543 1572-8919 |
DOI: | 10.1007/s10924-020-02042-w |