The Ring-Opening Polymerization of D,L-Lactide in the Melt Initiated with Tetraphenyltin

Content Provider	Semantic Scholar
Author	Kohn, F. E. Berg, J. Van Den Ridder, G. Van De Feijen, Jan
Copyright Year	1984
Abstract	Melt polymerization conditions for D,L-lactide initiated with tetraphenyltin were studied with regard to polymer molecular weight and weight distributions. "Single" polymerization, "multiple"polymerization (four or eight reactions at the same time), and time-dependent studies are described. Single polymerizations using constant initiator concentrations resulted in a broad scattering of nonreproducible molecular weight values. Multiple polymerizations at constant initiator concentrations, however, resulted in nearly identical molecular weight profiles. Multiple polymerizations at different initiator concentrations did not show an inverse dependency of initiator concentration on polymer molecular weight. Both the single and multiple melt polymerizations resulted in rather broad molecular weight distributions. The presence of hydrolysis products of lactide during the melt polymerization most likely has a detrimental effect on molecular weight. After a short induction period the rather slow polymerization of D,L-lactide resulted in a maximal molecular weight followed by a slight decrease in molecular weight to a constant value. It is concluded that the polymerization of D,L-lactide in the melt initiated with tetraphenyltin does not proceed through a "living" mechanism.
Starting Page	4265
Ending Page	4277
Page Count	13
File Format	PDF HTM / HTML
DOI	10.1002/app.1984.070291255
Volume Number	29
Alternate Webpage(s)	http://doc.utwente.nl/70795/1/Kohn84ring.pdf
Alternate Webpage(s)	https://ris.utwente.nl/ws/portalfiles/portal/6434940
Alternate Webpage(s)	https://doi.org/10.1002/app.1984.070291255
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article