Redox‐gesteuertes Entkleben von Muschel‐inspirierten Haftklebstoffen: Effizienzsteigerung durch funktionales Design

Abstract

Debondable pressure‐sensitive adhesives (PSAs) promise access to recyclability in microelectronics in the transition toward a circular economy. Two PSAs were synthesized from a tetravalent thiol star‐polyester forming thiol‐catechol‐connectivities (TCC) with either biorelated DiDopa‐bisquinone (BY*Q) or fossil‐based bisquinone A (BQA). The PSAs enable debonding by oxidation of TCC‐catechols to quinones. The extent of debonding efficiency depends on the interaction modes, which are determined by the chemical structure differences of both TCC‐motifs. BY*Q‐TCC‐PSA debonds with exceptional loss of 99% of its approx. 2 MPa shear strength. For BQA‐TCC‐PSA, a debonding efficiency of only approx. 60% was found, irrespective of its initial shear strength, which could be tuned up to approx. 7 MPa. The efficiency of debonding for BY*Q‐TCC‐PSA after TCC‐oxidation is linked to the loss of synergistic interactions without strongly affecting the bulk glue properties, outperforming the purely catechol‐based BQA‐analogue.