Facile anionic synthesis of a well-controlled thermally cross-linkable block copolymer for polymer-based resistive memory device applications

Abstract

The reactivities of 4-[(trimethylsilyl)ethynyl]styrene (A) and 4,4'-vinylphenyl-N,N-bis(4-tert-butylphenyl)benzenamine (B) were investigated by sequential anionic block copolymerization to synthesize a thermally cross-linkable block copolymer for memory device applications. From the investigation on the reactivities of the monomers, the well-defined poly(B-b-A) was synthesized in a simple manner by sequential addition of B as the first monomer and A as the second monomer using the commercially available s-butyllithium (s-BuLi) initiator in THF at −78°C. The sequential deprotection was then performed to prepare the deprotected polymer (d-poly(B-b-A)) containing the triphenylamine group as the conducting moiety and the ethynyl group as the thermal cross-linker, and the resulting thermally cross-linked polymer was used as an active layer of the memory device. The device fabricated with cross-linked d-poly(B-b-A) exhibited the write-once-read-many times (WORM) nonvolatile memory behavior, which is governed by the space-charge-limited current (SCLC) conduction mechanism and filament formation.

Precise synthesis of thermoreversible block copolymers containing reactive furfuryl groups via living anionic polymerization: the countercation effect on block copolymerization behavior

“…In particular, this [4 + 2] cycloaddition reaction between a diene and a dienophile is a thermally reversible process, and therefore cross-linked polymeric products prepared via the DA reaction can be used for self-healing applications. [38][39][40][41][42][43] Thermally cross-linkable block copolymers, poly(4-ethynylstyrene)-b-poly(A)-b-poly(4-ethynylstyrene) and poly(A)-b-poly(4-ethynylstyrene), have been synthesized as an alternative hole-transporting layer to PEDOT: PSS in polymer light-emitting diodes and an active layer of the memory device. From the synthetic point of view, successful living anionic polymerization of functional monomers allows preparation of welldefined block copolymers with various functionalities.…”

“…[34][35][36][37] For example, the living character of 4,4′-vinylphenyl-N,N-bis(4-tertbutylphenyl)benzenamine (A) provides us with many opportunities to synthesize controlled functional block copolymers for a variety of applications. [38][39][40][41][42][43] Thermally cross-linkable block copolymers, poly , have also been prepared for using in polymer memory device applications.…”

Organic Field-Effect Transistors with Bottlebrush Polymer Gate Dielectrics Thermally Cross-Linked in Less Than 1 min

“…The cross-linking temperature for each bottlebrush polymer was evaluated from the exothermic peak during the first heat cycle of the DSC thermogram (Figure b). The exothermic peaks were clearly observed at approximately 210 °C (for P1 and P2) and 220 °C (for P3 and P4), indicating that the alkyne cross-linking reaction can proceed at temperatures of >210 °C (for P1 and P2) and >220 °C (for P3 and P4), respectively. , Interestingly, P1 and P2 (i.e., homopolymers) showed relatively lower cross-linking temperatures and larger areas of the peaks compared to those of P3 and P4 (i.e., co-polymers). We attribute the slightly lower cross-linking temperature of P1 and P2 to the relatively higher density of alkyne groups in the P1 and P2 thin films.…”

“…Because each polymeric side chain can hold multiple functional groups, bottlebrush polymers can have a larger number of functional groups in a single polymer chain compared to that of conventional linear polymers. Thus, if thermally cross-linkable functional groups such as alkyne functionality are covalently incorporated into grafted side chains of bottlebrush polymers, a more efficient and instant thermal-cross-linking reaction would be expected without the use of additional cross-linking agents. ,, More importantly, because the degree of polymerization (DoP) of bottlebrush polymers can be finely controlled by living polymerization techniques such as living anionic polymerization (LAP) and ring opening metathesis polymerization (ROMP), a more reproducible dielectric property and the resulting device performance would be anticipated if bottlebrush polymers were incorporated into OFETs . Considering that for plastic electronics, the batch-to-batch problem is one of the chronic obstacles to commercialization, bottlebrush polymers with well-controlled DoP values can be beneficial for the commercialization of OFET-based electronic devices with reliable device performance.…”

Precise Synthesis of Functional Block Copolymers by Living Anionic Polymerization of Vinyl Monomers Bearing Nitrogen Atoms in the Side Chain

“…VPTBTPA and TMVPES have been quantitatively polymerized with commercially available one directional initiator ( sec ‐BuLi) that can be used without a preparation process. The sequential block copolymerization technique allowed us to synthesize the well‐defined thermally cross‐linkable block copolymer poly(VPTBTPA)‐ b ‐poly(TMVPES) as an active layer for polymer‐based resistive memory applications …”