Comparison of salicylate-based poly(anhydride-esters) formed via melt-condensation versus solution polymerization

Abstract

Salicylate-based poly(anhydride-esters) were synthesized via two different methods, melt-condensation and solution polymerization, and the resulting polymers were compared. Acetylsalicylic acid was used as a model compound to mimic the active polymer chain-ends during melt-condensation, and formed a low-molecular-weight (<1500) polymer when subjected to melt-condensation polymerization conditions. The polymers and model compounds were analyzed by NMR ((1)H and (13)C) and IR spectroscopies to elucidate the structures. Spectroscopic analysis revealed the formation of a thermodynamically stable salicylate ester via salicylate-anhydride rearrangement during melt-condensation polymerization, which did not occur during solution polymerization. The salicylate-based poly(anhydride-esters) undergo a thermodynamic rearrangement during melt-condensation polymerization that is not observed for solution polymerization.

Ferulic Acid-Based Polymers with Glycol Functionality as a Versatile Platform for Topical Applications

“…Polymer (5) was prepared using a modified literature procedure (Scheme 1). 29 In brief, 4 (1 eq) was suspended in anhydrous DCM 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 according to Equation 3 where w w refers to wet weight and w d refers to dry weight. All studies were performed in triplicate.…”

Polyactives: controlled and sustained bioactive release via hydrolytic degradation

“…For instance, our laboratory reported the synthesis of salicylate-based PAEs by melt-condensation and solution polymerization methods; these polymers are capable of achieving controlled and extended release of the salicylates through surface erosion. 29 Salicylate-based polymers are unique because non-steroidal anti-inflammatory drugs (NSAIDs) are chemically incorporated into the polymer backbone, instead of being physically admixed with the polymer. 30, 31 Likewise, the Uhrich group has chemically incorporated other NSAIDs, such as ibuprofen and naproxen, as pendant groups into PE backbones through their propionic acid moiety.…”

Poly(anhydride-esters) Comprised Exclusively of Naturally Occurring Antimicrobials and EDTA: Antioxidant and Antibacterial Activities

“…33,34 PDI values were narrow (1.3–1.5) following isolation from the reaction mixture, indicating high homogeneity. The polyanhydride with the bulkiest antimicrobial, eugenol ( 4c ), was the most difficult to polymerize and displayed the lowest molecular weight.…”

“…Solution polymerization was chosen instead of melt-condensation to prevent potential ring closure and regeneration of the EDTA dianhydride, 5 . 34 Polymers were characterized by 1 H NMR to confirm structure. Additionally, FT-IR (Figure 2) confirmed the synthesis of a poly(anhydride-ester) through the disappearance of the carboxylic acid stretch at 1712 cm –1 in diacid 4 and the appearance of the C=O anhydride stretches at 1815 and 1745 cm –1 in polymer 5 .…”