Polylactones. 41. Polymerizations of β-d,l-Butyrolactone with Dialkyltinoxides as Initiators

Abstract

The usefulness of dimethyl-, diethyl-, dibutyl- and dioctyltin oxide for the preparation of syndiotactic poly(β-d,l-butyrolactone) was studied. Most polymerizations were conducted in bulk and a few polymerizations in toluene or chlorobenzene. The reaction temperature was varied between 50 and 100 °C. Below 50 °C the initiatiors were not reactive enough. Me2SnO proved to be the least reactive initiator. High yields and the highest molecular weights (M n's up to 80 000 and M w up to 130 000) were achieved with Bu2SnO. These high molecular weights were obtained at low monomer/initiator ratios (M/I = 50−400). In contrast to literature data, no conversion was observed at M/I ratios >600 regardless of the reaction conditions. The highest percentage of syndiotactic diads (72%) resulted either from polymerizations with Bu2SnO at 50 °C or with Et2SnO at 100 °C. Transparent films with high expansibility were cast from the 63 and 70% syndiotactic polybutyrolactone samples, which may be useful as biodegradable packaging materials.

Structure and morphology of poly(?-hydroxybutyrate) synthesized by ring-opening polymerization of racemic (R,S)-?-butyrolactone with distannoxane derivatives

“…However, polymerization results for ( R,S )‐β‐BL show that in the presence of catalysts such as dichloro‐distannoxane and dibutyltin oxide oily polymers with very low yields and molecular weights are obtained. The poor result obtained with Bu 2 SnO contrasts with the good results reported by Hori22 and Kricheldorf 33. For the time being, we have no explanation for this discrepancy, because we always work with high purity products and under high vacuum.…”

Novel Stannylenes Stabilized with Diethylenetriamido and ­Related Amido Ligands: Synthesis, Structure, and Chemical Properties

“…The chemistry of carbene analogues of the heavier group 14 elements has attracted significant interest due to their unique properties and reactivity 1. Tin(II) compounds have been used as precursors for metal organic chemical vapor deposition (MOCVD)2 and as catalysts in ring‐opening polymerization of lactide and glycolide,3 ring‐opening copolymerization of ( D , L )‐lactide and glycolide,4 polymerizations of β‐ D , L ‐butyrolactone,5 and β‐butyrolactone6. At the same time, stannylenes are an important class of ligands in coordination and organometallic chemistry 7…”

Ring-opening copolymerization of (R,S)-β-butyrolactone and ε-caprolactone using sodium hydride as initiator

“…On the other hand, the choice of a proper initiator is another important parameter in the synthesis of polyesters. Many effective catalysts based on tincompounds, have been employed for this purpose [4,7,8,[13][14][15][16][17][18][19][20][21]. However, many are relatively toxic and impossible to remove completely from the synthesized material, this being undesirable for pharmaceutical or biomedical applications [2,6].…”