Triggerable, Anchoring Novel Block Copolymer Dyes for Use in Inkjet Printing

Project Information

TANBCPdyes

Grant agreement ID: 832787

DOI

10.3030/832787

Project closed

EC signature date 9 April 2019

Start date 1 September 2020

End date 4 November 2022

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 224 933,76

EU contribution

€ 224 933,76

Coordinated by

ASTON UNIVERSITY
United Kingdom

Periodic Reporting for period 1 - TANBCPdyes (Triggerable, Anchoring Novel Block Copolymer Dyes for Use in Inkjet Printing)

Reporting period: 2020-09-01 to 2022-08-31

Summary of the context and overall objectives of the project

This project, “Triggerable, Anchoring Novel Block Copolymer Dyes (BCP dyes) for Use in Inkjet Printing” (TANBCPdyes), is an intersectoral multidisciplinary project working on the development of a new technology platform based on specially-designed materials (BCP dyes). The development of novel inkjet printing materials is greatly needed to satisfy the growing demands of this quickly evolving market which spans applications including simple home & office devices to food packaging and high-tech inkjet printing of displays. The synthesized BCP dyes have been designed to be processed from water, an environmentally friendly solvent (thus eliminating the use of hazardous volatile organic solvents in the process) and will become insoluble & water resistant after deposition on the substrate. Therefore, the new materials act as waterborne dyes in a wet state & become fixed onto the substrates after thermal treatment. Success will allow novel BCP dyes to be manufactured on a large scale at high-throughput levels by drawing on the expertise of the industrial partner, Domino UK Ltd, which will allow industries to reinforce their position in the global technological race in the field of inkjet printing and crucially shift from using toxic, hazardous organic solvents.

The key research objectives (RO) of TANBCPdyes are as follows:

RO1. Synthesis of novel triggerable anchoring BCP dyes.
RO2. Self-assembly capability and properties of BCP dyes in water.
RO3. Evaluation of triggerable behaviour and material properties in thin film.
RO4. Inkjet printing performance and anchoring on food packaging.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During the TANBCPdyes project, UV triggerable diblock copolymers (BCPs) have been synthesized in three steps via well-controlled RAFT polymerization and post-polymerization esterification reaction for application in inkjet printing. Poly(2-hydroxyethyl acrylate) macro-chain transfer agent with targeted degree of polymerization (Dp) 120 and 160 [macro-CTA1: P(HEA)120-CPDT; macro-CTA2: P(HEA)160-CPDT] were first synthesized via RAFT polymerization of 2-hydroxyethyl acrylate (HEA) in the presence of chain transfer agent cyano-2-propyl dodecyl trithiocarbonate (CPDT). The 1H NMR and GPC data confirm the successful synthesis of macro-CTA1 and macro-CT2. Then amphiphilic BCPs were synthesized by the chain extension of macro-CTA1 and macro-CTA2 with hydrophobic block derived from propyl methacrylate (PMA) monomer via RAFT polymerization in N,N-dimethyl formamide. The chain extension of macro-CTA1 and macro-CTA2 with second hydrophobic poly(PMA) block was achieved after 100 h polymerization of PMA. The % conversion of PMA, DP, the number average molecular weight (Mn), the average molecular weight (Mw) and Mw/Mn values confirm the synthesis of BCPs: Poly[(HEA)84-b-(PMA)11] and poly[(HEA)105-b-(PMA)12] via well-controlled RAFT polymerization.
Finally, UV-crosslinkable diblock copolymers have been created after post functionalization of amphiphilic BCPs with UV-triggerable cinnamic acid (CMA) by performing esterification at room temperature (RT). The post functionalization of BCPs with different amounts of UV-triggerable moiety was accomplished upon completion of esterification reaction within 72 h. UV-triggerable BCPs: CMA16-poly[(HEA)68-b-(PMA)11] and CMA27-poly[(HEA)78-b-(PMA)12] self-assembled in waterborne ethanol-water mixture (70:30 v/v). Unimodal particle size distribution was observed for 2 wt.% solution of UV-triggerable BCPs. Triggerable behaviour of BCPs was evaluated by UV-crosslinking thin films of CMA16-poly[(HEA)68-b-(PMA)11] and CMA27-poly[(HEA)78-b-(PMA)12] using a high intensity UV lamp. UV-triggerable BCPs are quickly crosslinked upon the exposure of UV light for a specific time. Only 3 to 5 minutes of exposure to UV light was found to be adequate for the crosslinking of both BCP thin films. The chemistry was then scaled up to produce these champion block copolymers in larger quantity. Samples of UV-triggerable BCPs (15 g in each case) have been supplied to Domino Printing Sciences (Cambridge, UK) for evaluating their printability and anchoring capability on hydrophobic substrates. It is noted that the study printability and anchoring capability of UV-triggerable BCPs is expected to be completed soon at Domino.
The results produced during the tenure of TANBCPdyes project would be exploited and disseminated through publications into the reputed journals as follows.
[1] M. Kumar, G. Maitland, M. Derry, J. J.L. Harries and P.D. Topham, Synthesis of UV-triggerable cinnamic acid functionalized diblock copolymers via controlled RAFT polymerization for ink-jet printing, Polymer Chemistry 2022 (Manuscript to be communicated soon).
[2] M. Kumar, J. Godlemann, M.J. Derry, J. J.L. Harries and P.D. Topham, Synthesis of Anthracene based UV triggerable block copolymers via controlled RAFT polymerization for ink-jet printing, Macromolecules, 2022 (Manuscript to be communicated soon).

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Diblock copolymers CMA16-poly[(HEA)68-b-(PMA)11] and CMA27-poly[(HEA)78-b-(PMA)12] developed in this project are capable to self-assemble in 70:30 (v/v) ethanol-water at room temperature and crosslinked with 3 to 5 min upon the exposer of UV light. The production of such type diblock copolymers via well-controlled RAFT polymerization and post functionalization could be achievable on large scale for use in ink formulations. Due to these benefits, diblock copolymers could be utilized in developing UV curable ink formulations without usage of toxic volatile organic solvents and harmful photoinitiators, monomers and oligomers. UV curable diblock copolymers enabled ink formulations can be explored for commercial inkjet printing on hydrophobic substrates in the food packaging industry. The risk of food packaging contamination by inkjet inks could be overlooked. The long-term stability of printed ink on the food substrates is achievable after UV crosslinking over a short duration. The usage of water-borne solvents mixture (70:30 (v/v); ethanol-water and rapid crosslinking time of diblock copolymers could enable cleaner new printing technology in the food packaging industry at low production cost.

Figure for publication