The Diels–Alder (DA) reaction is regarded as quite a useful strategy in organic and macromolecular syntheses.

A series of bio-based epoxidized plasticizers (CExEp) for soft PVC was synthesized from cardanol and various fatty acids by esterification and epoxidation of the fatty and cardanol unsaturations. The plasticizing properties of these additives for PVC films were proved considering thermal and mechanical data. They seem to be a good bio-based alternative plasticizer to diisononyl phthalate (DINP), one of the most widespread phthalate plasticizers, with more flexible and stable films. Non epoxidized plasticizers (CEx) give satisfying results as secondary plasticizers of DINP whereas epoxidized ones act as primary plasticizers. The synergy between epoxy groups and cardanol ring to elaborate efficient primary plasticizers was demonstrated. Moreover, the eco-toxicity using daphnies, algae, and plants as model organisms and endocrinal disruptor tests (YES/YAS) were realized on the best candidate. Our results revealed that the fatty cardanol plasticizer causes a global decrease in toxicity compared to DINP and no harm for environment and human health were detected without reprotoxicity effect.

Commercial novolac‐type phenolic thermosets are mainly synthesized from highly toxic precursors such as phenol and formaldehyde. Herein, the phenolic chemistry is renewed with bio‐based and non‐toxic precursors such as cardanol and nonanal to elaborate flexible phenolic thermosets. The two‐step novolac strategy involves the synthesis of a cardanol nonanal pre‐polymer (PCN) prior to its cross‐linking in presence of a supplementary amount of nonanal hardener. The curing process is optimized by rheology measurement and thermogravimetry analysis. The alkyl chains of this phenolic network induces soft mechanical properties acting as internal plasticizers. The softening of the resulting networks do not induce a loss of thermal stability. Showing a good compromise between softness and high thermal resistance, cardanol‐nonanal networks (RCN) seem to be relevant examples of an innovative and biobased approach for phenolic chemistry to design bio‐sourced materials without any petro‐based or hazardous molecules. Practical Applications: Various practical applications where smooth and soft coatings are employed can be considered. Novolac chemistry for bio‐based and notoxic resources: cardanol and nonanal. Softness and high thermal resistance phenolic resins are elaborated. These materials are based on internal plasticized cross‐linked materials.

Well‐defined linear alkyl benzene surfactants (COxn) were successfully synthesized using cardanol as a green phenolic alternative and initiator for polyoxazoline (POx), the hydrophilic block of nonionic surfactants. Various hydrophilic lipophilic balance values were investigated by varying the POx length according to the [monomer]/[initiator] ratio. The chemical structure of the surfactants, in particular the terminal groups, was well identified by matrix assisted laser desorption ionization time of flight mass spectrometry demonstrating the good progress of the cationic ring‐opening polymerization. The COxn surfactants spontaneously self‐assembled in water at a critical aggregation concentration of 1–2 µmol L−1 into nano‐objects characterized by a hydrodynamic diameter of 11–24 nm and a number of aggregations ranging from 30 to 60 according to the worm‐like micelle model. © 2019 Society of Chemical Industry

Aims Our understanding of the rhizosphere is limited by the lack of techniques for in situ live microscopy. Current techniques are either destructive or unsuitable for observing chemical changes within the pore space. To address this limitation, we have developed artificial substrates, termed smart soils, that enable the acquisition and 3D reconstruction of chemical sensors attached to soil particles. Methods The transparency of smart soils was achieved using polymer particles with refractive index matching that of water. The surface of the particles was modified both to retain water and act as a local sensor to report on pore space pH via fluorescence emissions. Multispectral signals were acquired from the particles using a light sheet microscope, and machine learning algorithms predicted the changes and spatial distribution in pH at the surface of the smart soil particles. Results The technique was able to predict pH live and in situ within ± 0.5 units of the true pH value. pH distribution could be reconstructed across a volume of several cubic centimetres around plant roots at 10 μm resolution. Using smart soils of different composition, we revealed how root exudation and pore structure create variability in chemical properties. Conclusion Smart soils captured the pH gradients forming around a growing plant root. Future developments of the technology could include the fine tuning of soil physicochemical properties, the addition of chemical sensors and improved data processing. Hence, this technology could play a critical role in advancing our understanding of complex rhizosphere processes.

Surfactants are crystallizing a certain focus for consumer interest, and their market is still expected to grow by 4 to 5% each year. Most of the time these surfactants are of petroleum origin and are not often biodegradable. Cashew Nut Shell Liquid (CNSL) is a promising non-edible renewable resource, directly extracted from the shell of the cashew nut. The interesting structure of CNSL and its components (cardanol, anacardic acid and cardol) lead to the synthesis of biobased surfactants. Indeed, non-ionic, anionic, cationic and zwitterionic surfactants based on CNSL have been reported in the literature. Even now, CNSL is absent or barely mentioned in specialized review or chapters talking about synthetic biobased surfactants. Thus, this review focuses on CNSL as a building block for the synthesis of surfactants. In the first part, it describes and criticizes the synthesis of molecules and in the second part, it compares the efficiency and the properties (CMC, surface tension, kraft temperature, biodegradability) of the obtained products with each other and with commercial ones.

SummaryAgriculture must reduce green-house gas emission and pollution, produce safer and healthier food, closer to home, reducing waste whilst delivering more diverse diets to a growing world population. Soils could enable this transformation, but unfortunately, they have a hugely complex and opaque structure and studies of its myriad of mechanisms are difficult. Here, the fabrication of smart soils for the screening of below-ground bio-processes is demonstrated. Particles were generated from fluoropolymer waste with functionalisation converting them into sensors able to report on key chemical dynamics. Tailored functionalization was obtained by radical terpolymerisation to improve growth conditions and sensing capabilities. The study demonstrates the potential for the development of accelerated genetic or agrochemical screens and could pave the way for controlled indoor soil bio-production systems.

Lipidic polyols based on -hydroxyketone reactive groups were investigated for polyurethane thermosets. The reactivity of this peculiar secondary alcohol group in triglyceride structure was compared, without use of catalyst, to that of poly(1,2-diol)triglyceride and castor oil to demonstrate the influence of ketone in  position of alcohol group in presence of HDMI for urethanisation rate. The kinetic effect of ketone group was also studied on various lipidic architectures: mono(-hydroxyketone) ester, di(-hydroxyketone) diester and tri(hydroxyketone) triglyceride. The presence of hydrogen bonds in the network coming from urethane, residual alcohol and ketone in hard segments of PU was discussed and correlated to the thermal stability and the soft mechanical properties of the resulting polyurethane thermosets.