Development of New Lignin-Based Coatings with Ultraviolet Resistance for Biobased Composite Materials.

Nowadays, there is a challenge in searching for more sustainable alternatives to decrease the environmental impact of composite materials. In this work, we fabricate new composites based on a biobased-content epoxy system, lignin, and flax fiber; considering these materials could be promising due to their high renewable content of around 40%. In addition, another key requirement for composites, besides being sustainable, is that they present improved properties such as UV resistance.

Sustainable Epoxy Composites with UV Resistance Based on New Kraft Lignin Coatings.

Currently, the composite industry is focusing on more environmentally friendly resources in order to generate a new range of biobased materials. In this manuscript, we present a new work using lignocellulosic wastes from the paper industry to incorporate into biobased epoxy systems. The manufactured materials were composed of kraft lignin, glass fiber, and a sustainable epoxy system, obtaining a 40% biobased content.

Development of New Hybrid Composites for High-Temperature Applications.

Nowadays, in the automation and aircraft industries, there is a challenge in minimizing the weight of components of vehicles without losing the original properties. In this study, we fabricate hybrid composites based on fiber metal laminates; these materials could be promising composites for high-performance applications. This work is focused on analyzing the effect of high temperature (175 °C) on the mechanical properties of these kind of materials, by introducing NaOH and silane adhesion treatments between metal and prepreg layers and by using vacuum molding processes.

Sustainable Alternatives for the Development of Thermoset Composites with Low Environmental Impact.

The current concerns of both society and the materials industries about the environmental impact of thermoset composites, as well as new legislation, have led the scientific sector to search for more sustainable alternatives to reduce the environmental impact of thermoset composites. Until now, to a large extent, sustainable reinforcements have been used to manufacture more sustainable composites and thus contribute to the reduction of pollutants. However, in recent years, new alternatives have been developed, such as thermosetting resins with bio-based content and/or systems such as recyclable amines and vitrimers that enable recycling/reuse.

Fiber-Reinforced Polyester Composites with Photoluminescence Sensing Capabilities for UV Degradation Monitoring.

The wide application of fiber-reinforced polymer composite (FRPC) materials has given rise to the problem of their durability and performance over time. These problems are largely associated with their environmental conditions and service procedures, including ultraviolet (UV) irradiation. Here, we propose the production of polyester-based composites with different contents of synthesized YAlO:Ce,Ga (YAG:Ce,Ga) particles to provide sensing abilities towards material degradation.

A novel strategy to polyurethanes with improved mechanical properties by photoactivation of amidocoumarin moieties.

An attractive strategy involving photodimerization of a novel amidocoumarin moiety is presented to prepare polyurethane coatings with excellent mechanical properties. Two families of polyurethanes containing these chromophore units into soft or hard segments were easily synthesized by inserting a small fraction of amidocoumarin-diol (5 wt% or 10 wt%). A systematic study has been carried out comparing hard segment, chromophore content and the influence of this amidocoumarin unit within the hard or soft segment.

Structural Characterization of Mono and Dihydroxylated Umbelliferone Derivatives.

Coumarin derivatives are a class of compounds with a pronounced wide range of applications, especially in biological activities, in the medicine, pharmacology, cosmetics, coatings and food industry. Their potential applications are highly dependent on the nature of the substituents attached to their nucleus. These substituents modulate their photochemical and photophysical properties, as well as their interactions in their crystalline form, which largely determines the final field of application.

Coumarins into Polyurethanes for Smart and Functional Materials.

Polyurethanes are of undoubted interest for the scientific community and the industry. Their outstanding versatility from tailor-made structures turns them into major polymers for use in a wide range of different applications. As with other polymers, new, emerging molecules and monomers with specific attributes can provide new functions and capabilities to polyurethanes.