Synthesis and characterization of novel aliphatic polycarbonates

Abstract

A new six‐membered cyclic carbonate monomer, 5‐benzyloxy‐trimethylene carbonate, was synthesized from 2‐benzyloxy‐1,3‐propanediol, and the corresponding polycarbonate, poly(5‐benzyloxy‐trimethylene carbonate) (PBTMC), was further synthesized by ring‐opening polymerization in bulk at 150 °C using aluminum isobutoxide [Al(OiBu)3], aluminum isopropoxide, or stannous octanoate as an initiator. The results showed that a higher molecular weight polycarbonate could be obtained in the case of Al(OiBu)3. The protecting benzyl group was removed subsequently by catalytic hydrogenation to give a polycarbonate containing a pendant hydroxyl group (PHTMC). The polycarbonates obtained were characterized by Fourier transform infrared spectroscopy, 1H NMR,13C NMR, gel permeation chromatography, and DSC. NMR results of PBTMC offered no evidence for decarboxylation occurring during the propagation. The pendant hydroxyl group in PHTMC resulted in an enhancement of the hydrophilicity of the polycarbonate. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 70–75, 2002

Periodic Incorporation of Pendant Hydroxyl Groups in Repeating Sequence PLGA Copolymers

“…[21,23,24,28,29] Only in DMF was the deprotection viable. [30] We hypothesize that DMF promotes the hydrogenolysis by optimal solvation of both the relatively non-polar benzyl-protected polymer and the considerably more polar poly(hydroxyl) product and/or by providing the minimum activation enthalpy between the benzyl-protected polymers and the more polar transition state. Deprotection reactions gave nearly quantitative yields with deprotection rates generally >85% except in the case of poly S Ã (OH)L.…”

Synthesis and Characterization of Novel Biodegradable Copolymers of 5‐Benzyloxy‐1,3‐dioxan‐2‐one and Glycolide

“…Poly(5-benzyloxy-trimethylene carbonate) (PBTMC) is an aliphatic polycarbonate having a rubbery character at room temperature. [9][10][11] Compared with the conventional aliphatic polycarbonates, its monomeric unit, 5-benzyloxy-trimethylene carbonate (BTMC), can modify the properties of the resultant copolymers much more effectively because of the bulky lateral benzyloxy group. The copolymers we obtained can be dissolved in common organic solvents if the GA unit content is not very high.…”

“…Furthermore, it is possible to introduce functional hydroxyl groups to the polymer chains to facilitate further modification by deprotection of the benzyloxy groups. [9][10][11][12] Experimental Part…”

Synthesis and Characterization of N,N-Bis(2-hydroxyethyl) Cinnamamide as a Photo-Responsive Monomer

“…However, the synthesis of BLSMP has been a challenge due to the difficulty in synthesis of photo-sensitive functional monomer. Usually, functional biodegradable polymers can be synthesized from ring-opening (co)polymerization of functional cyclic ester or carbonate monomers, but the synthesis of such functional monomers is quite difficult and often suffers from multistep reaction, protection and de-protection of groups and low yield [6][7][8]. In this paper, we report a facile synthesis and characterization of N,N-bis(2-hydroxyethyl) cinnamamide (BHECA), a diol monomer which can be used to synthesize BLSMP or other photo-responsive polymers via polycondensation or polyaddition reaction rather than chain polymerizations.…”