The use of light as a unique tool in modern polymer chemistry has fueled the advancement of manufacturing techniques, e.g. coatings or 3D printing. Among suitable initiating species for photopolymerization reactions, photobase generators (PBG) have gathered increasing attention in recent years. They offer remarkable advantages to the broadly used photoradical generators (PRG), as they do not suffer from oxygen inhibition, can be used with a wider variety of monomers and are usually not associated to polymerization induced volumetric shrinkage of the final material [1], [2]. Additionally, unlike their photoacid generator (PAG) counterparts, they are compatible with metal substrates, thus allowing their use in automotive and electronic industries [1], [3].
Most literature reported PBGs, however, are bound to harmful UV light absorption and typically only liberate active species with a low basicity [2], [3]. We opt to address these challenges by introducing new PBGs with the ability to liberate a phosphazene superbase (pKa > 30) via a photodecarboxylative strategy [4]. They feature remarkable absorption patterns at high wavelengths (> 340 nm) extending to the visible light region as well as good thermal stabilities.
We additionally demonstrate their outstanding capacity in initiating a Brønsted base mediated oxa-Michael addition reaction between an alcohol and an acrylamide. Following a systematic monofunctional optimization study in a photo-DSC setup, the prospect of expanding this methodology to the PBG mediated synthesis of linear poly(ether-amide)s is introduced.

Ugi multicomponent reaction (Ugi MCR) is a versatile and efficient approach for synthesizing polypeptoids with high atom economy, mild reaction conditions, and structural diversity. Polymerization-induced Self-Assembly (PISA), on the other hand, has been acknowledged and widely employed in fabrication of water-dispersed nanoparticles with tuneable morphologies. In this study, we demonstrate an unprecedented combination of Ugi MCR and PISA, enabled by Reversible Addition-Fragmentation chain-Transfer (RAFT) polymerization, to provide polypeptoid-decorated nanoparticles in water. For that purpose, Boc-protected poly(ε-L-Lysine) was synthesized by Ugi MCR in presence of a carboxylic acid-bearing RAFT chain-transfer agent (CTA). The end-chain functionalization of the polypeptoid with the CTA was validated by NMR analyses (1H and 13C), UV-Vis and MALDI-ToF. Following by a Boc-deprotection, the resulting charged polypeptoid is soluble in water and, hence, was used as macroCTA for PISA-RAFT of 2-hydroxypropyl methacrylate in aqueous medium. As characterized by SAXS, TEM and DLS, by varying the hydrophobic block length and monomer concentration, nanoparticles of varied sizes could be obtained for two macroCTAs of different molar masses. This approach offers a robust pathway for designing functional nanoparticles with potential applications in biomedicine, catalysis, and advanced materials.

Since the origin of polymers, it is known that the molecular weight of polymers drastically decreases upon exposure to mechanical forces. 1,2 Even today this is still an important subject of discussion as methods to direct translate/visualise of mechanical failure in early stages are still lacking. Mechanophores are compounds that may/can detect early stages of mechanical failure modes. Mechanophores respond to mechanical energy through optical means either by: colour, fluorescence and most interesting (mechano)luminescence.3 On the latter no example exist for high performance engineering materials such as poly-aramids like poly(para phenylene terephthalamide), PPTA. The highly and para crystalline nature poses strict requirements on the design of mechanophoric mechanisms. We take inspiration from nature, selecting a naturally occurring compound found in the American firefly referred to as “(D-)Luciferin” which shows chemiluminescence upon oxidation (fig.1), producing a bright green light with exceptionally high quantum yields (42%).4 It’s envisioned that the luminescent properties, high quantum yield associated with Luciferin and highly aromatic structure could be utilised to function as a novel stress indicator in aramid materials (fig.1). In this presentation, we disclose chemical strategies in the atom efficient Asinger reaction for monomer synthesis, polymerization routes, liquid crystalline behaviour, spinnability and initial structure – function relationships of new mechanophoric high performance materials.

The highly controlled and efficient polymerization of ethylene is a very attractive but challenging target. Herein we report on a Coordinative Chain Transfer Polymerization (CCTP) catalyst, which combines a high degree of control and very high activity in ethylene oligo- or polymerization with extremely high chain transfer agent (triethylaluminum) to catalyst ratios (catalyst economy). Our Zr catalyst is long living and temperature stable. The chain length of the polyethylene products increases over time under constant ethylene feed or until a certain volume of ethylene is completely consumed to reach the expected molecular weight. Very high activities are observed if the catalyst elongates 60,000 or more alkyl chains and the polydispersity of the strictly linear polyethylene materials obtained are very low. The key for the combination of high control and efficiency seems to be a catalyst stabilized by only one strongly bound monoanionic N-ligand.
The new catalyst system was used to synthesize macro-monomers, di-, grafted- and sequential HDPE block copolymers, which can be used as compatibilizers, LDPE mimics etc..

New N-type conjugated polymers of low synthetic complexity based on difluoro-alkoxyquinoxaline, difluoro-alkylbenzotriazole or alkyl-thiadiazolobenzotriazole with double, triple, thiophene and difluoro substituted thiophene (Figure 1) are synthesized and characterize with the aim to be used as electron acceptors in indoor organic solar cells. The polymers are synthesized by Stille cross-coupling polycondensation and characterized with respect to their optical (UV-Vis), electrochemical (cyclic voltammetry), microstructure (GIWAXS) and charge transporting (SCLC) properties.