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Depto. de Química Física, Fac. de Ciencias Químicas, TRUE, pub

[EN] The European Green Deal policy ambitions set out in the Chemicals Strategy for Sustainability and the Zero Pollution Action Plan identify the transition to a Safe and Sustainable by Design (SSbD) approach to chemicals and materials. The H2020 SUNSHINE project has developed an approach to operationalize SSbD, specifically addressing multi-component nanomaterials (MCNMs), and applied it to two case studies. This approach enables assessment of safety and sustainability aspects at each stage of product development from a lifecycle perspective. This is achieved via a tiered approach that uses qualitative (Tier 1), semi-quantitative (Tier 2) and quantitative (Tier 3) assessment methods. The present work focuses on the Tier 1 (self-assessment) methodology designed to evaluate the safety, functionality and sustainability in the early R&D stages of the lifecycle of chemicals and materials. This approach was developed to be implementable by industries in a straightforward manner as often there is lack of time and/or expertise to engage in resource-intensive safety and sustainability evaluations. The approach was tested using two real industrial case studies, namely nano-enabled PFAS (Polyfluoroalkyl substances)-free anti-sticking coating for bakery molds, and nano-drops of essential oil anchored to the surface of nano clays and encapsulated in a polymeric film. The results indicate that these innovative materials have a high probability to have better safety, functionality and sustainability performance compared to conventional benchmark materials.

The present invention relates to functional cellulose and functional polyester materials and a preparation process thereof that comprises the activation of a compound with carbonylbiscaprolactam (CBC), and wherein the compound comprises at least an N-halamine precursor group; impregnating the material comprising cellulose or partially hydrolyzed polyester with a solution containing the activated compound; drying and curing the impregnated material to obtain the material functionalised in its surface with the compound. The functionalised material that has good durability, resisting tenths of washing cycles without losing its properties, and also having virucidal and bactericidal properties.

In this work, the modification of ethylene-co-vinyl alcohol (EVOH) copolymer with a coumarin derivative, 7- (hydroxyethoxy)-4-methyl coumarin (HEOMC), has been performed through the incorporation of different reactive groups, p-nitrophenyl chloroformate, succinic anhydride and phthalic anhydride as different linkers between coumarin and EVOH with the aim to obtain photo-responsive materials with improved protein absorption resistance. After purification, the modification degree was calculated by nuclear magnetic resonance and ultraviolet- visible spectroscopy. The thermal properties revealed the crystallinity loss and higher maximum degradation temperatures when EVOH is modified with coumarin derivative. Copolymers were successfully photocrosslinked through the photo-responsive behavior of coumarin moieties. The micro-hardness test shown an increase of the mechanical performance due to the coumarin presence. The water contact angle measurements revealed that while coumarin-modified EVOH copolymers present a higher hydrophilic behavior than EVOH, the photo-dimerization process mainly leads to slightly deviations on the surface wettability of neat EVOH. Finally, the absorption of bovine serum albumin onto the surface of the coumarin-modified materials revealed enhanced antifouling properties, particularly after the photo-crosslinked process. Therefore, the introduction of coumarin through different chain extenders leads to functional materials with tunable photo-responsive performance and protein absorption resistance.

Smart and functional properties of coumarin and PCL-based polyurethane (PU) nanocomposites reinforced with both pristine silica nanoparticles and silica nanoparticles modified with coumarin, have been studied. Coumarin is a photo-responsive derivative, which induces photo-crosslinking when it is incorporated in the PU moieties. Swelling measurements were performed to study the photo-crosslinking fraction and the results are in concordance with the degree of crosslinking (DC) calculated by UV measurements. Shape memory behavior was studied by thermo-mechanical cycles, by measuring the strain recovery and shape fixity ratios of the photo-crosslinked films. The modification of silica nanoparticles allows an improvement in the dispersion of the reinforcements into the PU matrix, which leads to an enhancement of the shape memory properties. Finally, the materials were disintegrated under composting conditions at laboratory scale level to confirm their biodisintegrable behavior.

Enzymatic polymerization has a large potential as an environmentally friendly synthetic process. Lipase is a renewable catalyst with high catalytic activity from which it is possible to develop a versatile method for the production of sustainable polyurethanes. In this work oligomeric PCL-diol was synthesized using biocatalysis with immobilized Yarrowia lipolytica lipase (YLL) and diethyleneglycol as initiator. Then, two different linear polyurethanes were prepared. One was obtained directly from the previous synthesized PCL-diol and hexamethylene diisocyanate, named PU, and the other one has been obtained by incorporating L-lysine amino acid as end group (lys-PU). PU and lys-PU disintegration under composting conditions was evaluated. The influence of the presence of L-lysine on the disintegration performance of PU was studied by evaluating the disintegration degree, monitoring the weight loss. Structural and morphological changes were followed by Fourier transformed infrared spectroscopy (FTIR) and by scanning electron microscopy (SEM).