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DOI: 10.1016/j.eurpolymj.2016.04.018 Thiol-Michael addition of pentaerythritol tetrakis(3-mercaptopropionate) (PE3MP) to a high oleic sunflower oil derivative containing enone groups (ETG), has been used to prepare vegetable oil derived renewable thermosets in an efficient way and under mild conditions. The same formulation has been used to prepare nano-biocomposites by incorporating into the polymerization mixture, 1 wt%, 5 wt% and 10 wt% of cellulose nanocrystals (CNC) modified with Beycostat A B09® as surfactant. The chosen methodology allows a good dispersion of the nano filler in a low polarity reactive media which still is a challenging approach. The morphological, thermal and mechanical properties of the different nano-biocomposites were evaluated and compared with the pristine thermoset. Morphological analysis shows that good dispersion of the nanofillers is achieved in all formulations. Mechanical properties show an improvement of the Young Modulus for all nanofiller contents, showing a maximum at 5 wt% loading (32 and 78 MPa for the pristine and 5% CNC nano-composite respectively) that has been related with the reinforcement effect of the modified CNC. CNC dispersion also affects positively the surface properties, thus reducing drastically the contact angle values (78.0-16.0°for the pristine and 10% CNC nano-composite respectively). Finally, protein adsorption was measured in order to evaluate potential application of these materials as biosensors and cell growing supports.

We report on the preparation of a new class of polymer hydrogels obtained through the chemical crosslinking reaction of poly(vinyl alcohol) (PVA) and functionalized gold nanoparticles. Carboxylic group functionalized gold nanoparticles were synthesized, dispersed in a PVA matrix and allow to react with the hydroxyl groups of PVA at high temperature. FT-IR and swelling experiments carried out on the cross-linked samples confirmed that the crosslinking reaction took place. This is the first time, to our knowledge, that functionalized nanoparticles are used as chemical crosslinking agents.

10.1002/pola.26562 A novel phosphorus-containing vegetable oil (PETR) was prepared through phospha-Michael addition of a diphenyl phosphine oxide to the enone derivative of high-oleic sunflower oil (ETR). The reaction was investigated using the enone derivative of methyl oleate under conventional thermal heating and microwave irradiation. The kinetic study showed a great enhancement of reaction rate for the microwave-initiated addition. The crosslinking of ETR with diaminodiphenylmethane (DDM) via aza-Michael addition was also investigated under microwave irradiation, showing a noticeable acceleration of the curing. The new phosphorus-containing triglyceride was crosslinked with DDM to obtain phosphorus-containing vegetable oil-based thermosets of different phosphorus contents. Limiting oxygen index values from 26.4 to 35.0 for the final materials were obtained, demonstrating that the flame retardant properties of vegetable oil-based thermosets can be improved by adding covalently bonded phosphorus to the polymer