Self-catalyzed hydrolysis upon storage of the common RAFT chain-transfer agent (CTA) 4-cyano-4-[(thiothiopropyl)sulfanyl] pentanoic acid (CTPPA) is confirmed, where the nitrile group is transformed into an amide by catalysis from the adjacent carboxylic acid moiety. The amide-CTA (APP) is found to poorly control molecular weight evolution during polymerization of two methacrylates, methyl methacrylate (MMA) and N,N-(dimethylamino)ethyl methacrylate (DMAEMA), likely due to poor reinitiation speed in the pre-equilibrium. However, when attached to a macromolecule, the impact of this amide moiety becomes insignificant and chain extension proceeds as expected with CTPPA. In light of CTPPA and similarly hydrolyzable CTAs being extensively employed for aqueous polymerizations of methacrylates, these findings highlight the importance of CTA purity when performing RAFT polymerizations.

Cellulose nanofibril (CNF)-networks are modified by the addition of small amounts (below 10 wt%) of well-defined cationic nanolatexes synthesized through reversible addition–fragmentation chain-transfer-mediated polymerization-induced self-assembly (PISA). Minute amounts of nanolatex inclusions lead to increased tensile and shear moduli, indicating that nanolatexes can act as bridging-points between CNFs. At higher nanolatex content, this stiffening effect is lost, likely due to interactions between nanolatexes leading to plasticization. The influence of nanolatex content and size on interparticle distance is discussed and is used as a tool to understand the effects observed in macroscopic properties. Upon annealing, the stiffening effect is lost due to the softening of the nanolatexes, indicating that the core–shell morphology is a prerequisite for this effect. These systems form a versatile platform to develop fundamental insights into complex condensed colloidal systems, to ultimately aid in the development of new sustainable material concepts.

Biobased cellulose nanofibrils (CNFs) constitute important building blocks for biomimetic, nanostructured materials, and considerable potential exists in their hybridization with tailorable polymeric nanoparticles. CNFs naturally assemble into oriented, fibrillar structures in their cross-section. This work shows that polymeric nanoparticle additives have the potential to increase or decrease orientation of these cellulose structures, which allows the control of bulk mechanical properties. Small amounts of these additives (<1 wt%) are shown to promote the alignment of CNFs, and the particle size is found to determine a tailorable maximum feature size which can be modified. Herein, X-ray scattering allows for the quantification of orientation at different length scales. This newly developed method of measuring cross-sectional orientation allows for understanding the influence of nanoparticle characteristics on the CNF network structure at different length scales in hybrid cellulose-nanoparticle materials, where previously quantitative description has been lacking. It thus constitutes an important foundation for further development and understanding of nanocellulose materials on the level of their nanoscale building blocks and their interactions, which in turn are decisive for their macroscopic properties.