Date of Award
Summer 8-2007
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Polymers and High Performance Materials
Committee Chair
Dr. Robson Storey
Committee Chair Department
Polymers and High Performance Materials
Committee Member 2
Dr. Robert Moore
Committee Member 3
Dr. Douglas Wicks
Committee Member 4
Dr. Charles Hoyle
Committee Member 5
Dr. William L. Jarrett
Abstract
Aromatic-aliphatic poly[L-lactide-/>-(ethyleneoxyethylene terephthalateco- adipate)-6 -L-lactide] triblock copolymers were synthesized and characterized. Hydroxy-telechelic poly(ethyleneoxyethylene terephthalate-co-adipate) (PEOETA) was first prepared via polycondensation and then utilized as an initiator for the ring opening polymerization (ROP) o f L-lactide (LLA) in the presence of stannous octanoate (Sn(Ocfh). Formation o f the block copolymer was confirmed by *H NMR spectroscopy, GPC, DSC and AFM. The polymerization rate induced by the PEOETA macroinitiator was comparable to that o f a small molecule initiator. The mechanical and degradation properties failed to meet project objectives; therefore we focused more attention to the modification of a-hydroxy acid polymers for use in the creation o f degradable polyurethanes.
Linear poly(D,L-lactide) containing a single pendant carboxylic acid group (BHMBA-PDLLA) was synthesized via ring opening polymerization (ROP) o f D,Llactide using 2,2-bis(hydroxymethyl) butyric acid (BHMBA) as an initiator. Characterization of the BHMBA-PDLLA using NMR spectroscopy and gel permeation chromatography confirmed the presence o f the pendent carboxylic acid group and provided evidence o f a linear architecture. Degradation studies were performed on BHMBA-PDLLA polyesters by immersion into aqueous buffered solution (7.4 pH) held at a constant temperature of 37°C. Complete degradation o f the BHMBA-PDLLA occurred at times much earlier than those o f the controls. These poly(oc-hydroxy acid) polymers have shown promising degradation results when chain-extended using L-lysine diisocyanate methyl ester as the chain-extending agent.
Copyright
2007, Timothy Russell Cooper
Recommended Citation
Cooper, Timothy Russell, "BLOCK COPOLYESTERS BASED ON POLY(LACTIDE) AND AROMATICALIPHATIC POLYESTERS OF THE AA/BB TYPE AND ACID FUNCTIONALIZED POLY (LACTIDE) AND POLY(ESTER-URETHANE)S THEREFROM" (2007). Dissertations. 1262.
http://aquila.usm.edu/dissertations/1262