TY - JOUR

T1 - Blocked Phosphates as Photolatent Catalysts for Dynamic Photopolymer Networks

AU - Dertnig, Carina Anna

AU - Guedes de la Cruz, Gema del Carmen

AU - Neshchadin, Dmytro

AU - Schlögl, Sandra

AU - Grießer, Thomas

N1 - Publisher Copyright: © 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.

PY - 2022/11/24

Y1 - 2022/11/24

N2 - While latent catalysts are a well-established strategy for initiating and controlling the rate of polymerization reactions, their use in dynamic polymer networks is still in its infancy. The ideal latent catalyst should be thermally stable and release a highly active species in response to an external trigger. Here, we have synthesized a temperature resistant (>200 °C) organic phosphate with a photolabile o-nitrobenzyl protecting group that can be cleaved by UV light. Introduced in a visible light curable thiol-click photopolymer, the sequence-dependent λ-orthogonality of the curing and cleavage enables an efficient network formation at 451 nm, without premature release of the catalyst. Once cured, irradiation at 372 nm spatiotemporally activates the phosphate, which catalyzes transesterifications at elevated temperature. The formed catalyst has no effect on the thermal stability of the polymeric network and allows the activation of bond exchange reactions in selected domains of printed 3D objects.

AB - While latent catalysts are a well-established strategy for initiating and controlling the rate of polymerization reactions, their use in dynamic polymer networks is still in its infancy. The ideal latent catalyst should be thermally stable and release a highly active species in response to an external trigger. Here, we have synthesized a temperature resistant (>200 °C) organic phosphate with a photolabile o-nitrobenzyl protecting group that can be cleaved by UV light. Introduced in a visible light curable thiol-click photopolymer, the sequence-dependent λ-orthogonality of the curing and cleavage enables an efficient network formation at 451 nm, without premature release of the catalyst. Once cured, irradiation at 372 nm spatiotemporally activates the phosphate, which catalyzes transesterifications at elevated temperature. The formed catalyst has no effect on the thermal stability of the polymeric network and allows the activation of bond exchange reactions in selected domains of printed 3D objects.

KW - 3D Printing

KW - Photochemistry

KW - Polymers

KW - Shape Memory

KW - Vitrimer

UR - http://www.scopus.com/inward/record.url?scp=85143765986&partnerID=8YFLogxK

U2 - 10.1002/anie.202215525

DO - 10.1002/anie.202215525

M3 - Article

AN - SCOPUS:85143765986

VL - 62.2022

JO - Angewandte Chemie - International Edition

JF - Angewandte Chemie - International Edition

SN - 1433-7851

IS - 10

M1 - e202215525

ER -