Functionalized and Degradable Polyphthalaldehyde Derivatives

Abstract

<div><p>Polymers that depolymerize back to monomers can be repeatedly chemically recycled, thereby reducing their environmental impact. Polyphthalaldehyde is a metastable polymer that is rapidly and quantitatively depolymerized due to its low ceiling temperature. However, the effect of substitution on the physical and chemical properties of polyphthalaldehyde derivatives has not been systematically studied. In this work, we investigate the cationic polymerization of seven distinct <i>o</i>‑phthalaldehyde derivatives and demonstrate that judicious choice of substituents results in materials with a wide range of ceiling temperatures (from < –60 to 106 °C) and decomposition temperatures (109–196 °C). We anticipate that these new polymers and their derivatives will enable researchers to access degradable materials with tunable thermal, physical, and chemical properties.</p></div>

High-Performance Chain Scissionable Resists for Extreme Ultraviolet Lithography: Discovery of the Photoacid Generator Structure and Mechanism

“…28,47,48 In contrast, oPA derivatives have rarely been explored due to synthetic challenges (Scheme 1). 49 Commercially acceptable photoresists have high purity requirements, which motivated us to explore simple, high-yielding reactions and thorough methods of purification. We chose to prepare a brominated derivative from the corresponding diol via Swern oxidation as all other means of oxidation failed to generate the desired product in acceptable yield due to the formation of lactone side products.…”

Anionic Copolymerization of o-Phthalaldehyde with Epoxides: Facile Access to Degradable Polyacetals and Their Copolymers under Ambient Conditions

“…OPA could be polymerized through either cationic or anionic approaches. In the presence of Lewis acids, such as BF 3 , 3−8 SnCl 4 , 9 or GaCl 3 , 10 the cationic polymerization of OPA generates PPA samples that were proved to be macrocyclics. 11 Because such cyclic PPAs can be reversibly opened and closed, the size of the macrocyclics formed do not conform to monomer conversion, resulting in cyclic samples of high molar masses and broader polydispersities.…”

“…13,16,24,25 Recently, Aoshima and co-workers carried out at −78 °C the synthesis of various alternating copolymers via cationic copolymerization of OPA with vinyl ethers. 10,26,27 In all cases all the (co)polymerizations have to be carried out at lower temperature than T c (−36 °C) 9 of OPA irrespective of the comonomers used.…”

Biobased High-Performance Aromatic–Aliphatic Polyesters with Complete Recyclability

“…1−4 Developing chemically recyclable polymers that allow for recovery of the starting monomers via depolymerization is an attractive strategy to address the urgent issues of plastic sustainability. 5−15 Recently, important advances have been made for chemical recycling to monomers in polyesters, 16−20 polythioesters, 21−24 polycarbonates, 25−29 polyphthalaldehydes, 30,31 polyacetals, 32 and poly-(cyclic olefins). 33,34 Among these recyclable polymers, polyesters are promising candidates owing to their renewable resources and excellent biodegradability.…”