LAUSR

Poly(acrylic acid) (PAA) is produced on an industrial scale and widely-used in applications such as personal care products and cleaning formulations that end up "down-the-drain." Relatively high molecular weight PAA is considered poorly biodegradable, but little is known about the biodegradability of low molecular weight PAA at the wastewater treatment plant according to current regulatory and industrial OECD standards. We report the synthesis, separation, and characterization of a series of ultralow dispersity PAA oligomers (i.e., Đ <1.10) in the molecular weight range Mn ∼ 350-1200 Da and the results of biodegradability testing. Miniaturized, high-throughput screening studies in a parallel respirometer revealed a strong trend towards lower biodegradation at higher molecular weight; these results were confirmed and expanded using standardized method OECD 301F. Biodegradability reached ∼40% at Mn = 380 Da, ∼26% at Mn = 770 Da, and ∼17% at Mn = 1190 Da for discrete polyacid oligomers. These data not only shed light on potential biodegradation mechanisms for linear PAA, but also may inspire the future design of biodegradable PAA-containing macromolecules. This article is protected by copyright. All rights reserved.