Electronic Effects of Aluminum Complexes in the Copolymerization of Propylene Oxide with Tricyclic Anhydrides: Access to Well-Defined, Functionalizable Aliphatic Polyesters

2016 ◽  
Vol 138 (8) ◽  
pp. 2755-2761 ◽  
Author(s):  
Nathan J. Van Zee ◽  
Maria J. Sanford ◽  
Geoffrey W. Coates
Keyword(s):  
Propylene Oxide ◽  
Electronic Effects ◽  
Aliphatic Polyesters ◽  
Aluminum Complexes

scholarly journals An Investigation of the Organoborane/Lewis Base Pairs on the Copolymerization of Propylene Oxide with Succinic Anhydride

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 253 ◽  
Author(s):  
Lan-Fang Hu ◽  
Dan-Jing Chen ◽  
Jia-Liang Yang ◽  
Xing-Hong Zhang
Keyword(s):  
Propylene Oxide ◽  
Succinic Anhydride ◽  
Lewis Base ◽  
Molar Ratio ◽  
Base Pairs ◽  
Catalytic Systems ◽  
Aliphatic Polyesters ◽  
Lewis Bases ◽  
Molecular Weights ◽  
High Ester

The copolymerization of biorenewable succinic anhydride (SA) with propylene oxide (PO) is a promising way to synthesize biodegradable aliphatic polyesters. However, the catalytic systems for this reaction still deserve to be explored because the catalytic activity of the reported catalysts and the molecular weights of produced polyesters are unsatisfied. Herein, we investigate the copolymerization of SA with PO catalyzed by the organoborane/base pairs. The types of Lewis bases, organoboranes, and their loadings all have a large impact on the activity and selectivity of the copolymerization. High ester content of >99% was achieved when performed the PO/SA copolymerization using triethyl borane (TEB)/phosphazene base P1-t-Bu (t-BuP1) pair with a molar ratio of 1/1 at 30–80 °C. Using TEB/t-BuP1 pair with the molar ratio of 4/1 at 80 °C, the turnover of frequency (TOF) was up to 128 h−1 and clearly higher than the known TOF values (0.5–34 h−1) of the PO/SA copolymerization by previously reported catalysts. The number-average molecular weights (Mns) of the resultant polyesters reached up to 20.4 kg/mol when copolymerization was carried out using TEB/t-BuP1 (1/1, in molar ratio) at 30 °C.

Initial Studies of a Potent Antiheparin Agent (Ubiquin®)

1968 ◽  
Vol 20 (03/04) ◽  
pp. 588-595 ◽  
Author(s):  
E. B Goodsell ◽  
R. A Krause ◽  
E. T Kimura
Keyword(s):  
Side Effects ◽  
Acute Toxicity ◽  
Propylene Oxide ◽  
Toluidine Blue ◽  
Water Soluble ◽  
Per Se

SummaryUbiquin (oligo-3-(N-methylmorpholinium)-l,2-propylene oxide chloride) is a stable, water soluble, active heparin antagonist producing prompt neutralization when administered in a 1:1 ratio to rats and dogs. Initial studies indicate that it is devoid of any effect on coagulation per se; nor are there any obvious side effects manifested during the process of neutralization. The acute toxicity is less than that of other compounds in use: toluidine blue, protamine and hexadimethrine.

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