Lignin-Based Polyols with Controlled Microstructure by Cationic Ring Opening Polymerization

Lignin-based polyols (LBPs) with controlled microstructure were obtained by cationic ring opening polymerization (CROP) of oxiranes in an organosolv lignin (OL) tetrahydrofuran (THF) solution. The control on the microstructure and consequently on the properties of the LBPs such as hydroxyl number, average molecular weight, melting, crystallization and decomposition temperatures, are crucial to determine the performance and application of the derived-products. The influence of key parameters, for example, molar ratio between the oxirane and the hydroxyl groups content in OLO, initial OL concentration in THF, temperature, specific flow rate and oxirane nature has been investigated. LBPs with hydroxyl numbers from 35 to 217 mg KOH/g, apparent average Mw between 5517 and 52,900 g/mol and melting temperatures from −8.4 to 18.4 °C were obtained. The CROP procedure allows obtaining of tailor-made LBPs for specific applications in a very simple way, opening the way to introduce LBPs as a solid alternative to substitute currently used fossil-based polyols.Basque Government (grant KK-2019/00097

The future of isosorbide as a fundamental constituent for polycarbonates and polyurethanes

Isosorbide is a biobased compound which could become in the near future an advantageous competitor of petroleum-derived components in the synthesis of polymers of different nature. When the reactivity of isosorbide is not enough, it can be successfully transformed into secondary building blocks, such as isosorbide bis(methyl carbonate), which provides extra functionalities for polymerization reactions with diols or diamines. The present review summarizes the possibilities for isosorbide as a green raw material to be used in the synthesis of polycarbonates and polyurethanes to obtain products of similar or enhanced properties to the commercial equivalents.This paper is a part of the research carried out within the VIPRISCAR project which has received funding from the Bio-Based Industries Joint Undertaking (JU) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 790440. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and the Bio-Based Industries Consortium

Cyclic carbonates from CO2 and vegetable oils as bio-precursors for non-isocyanate polyurethanes development: A journey from monomer synthesis to industrial application.

199 p.Desde que en la década de 1930 Otto Bayer y sus colaboradores desarrollaron la reacción entre alcoholes e isocianatos, la expansión de los poliuretanos (PUs) ha llegado a tal punto que es incomprensible entender la vida moderna sin estos materiales. De hecho, la versatilidad de esta familia de polímeros ha permitido el uso de los PUs en numerosos campos y aplicaciones. Sin embargo, el uso de materias primas finitas y no renovables de origen fósil, junto con la creciente preocupación por el medio ambiente y la seguridad han impulsado la investigación de nuevas alternativas sintéticas a los PUs tradicionales. Por este motivo, el proceso para desarrollar PUs alternativos debe tener en cuenta estos factores: economía circular, reciclabilidad, seguridad, bajas emisiones y viabilidad industrial. El diseño de una nueva clase de polímeros para sustituir a los actuales PUs es uno de los mayores retos en la química de polímeros. El creciente interés por el desarrollo de procesos afines a los principios de la Química Verde ha impulsado a el uso de la biomasa como materia prima para la síntesis de PUs. En este contexto, la disponibilidad, no toxicidad, sostenibilidad, inherente biodegradabilidad, fácil manejo, bajo coste y estructura química bien definida, convierte a los aceites vegetales en una de las materias primas con mayor potencial para el desarrollo de distintos productos. La estructura de los aceites vegetales proporciona diferentes sitios activos, que pueden ser modificados para la obtención de polioles e isocianatos, como intermedios de PUs. No obstante, la síntesis de un PUs completamente basado en la biomasa no aborda el principal inconveniente de los PUs: La toxicidad de los isocianatos y sus precursores.Por esta razón en este trabajo se han desarrollado poliuretanos libres de isocianatos a partir de aceites vegetales, con el objetivo de facilitar la implementación industrial.ikerbasque. Tecnali

Recent advances in processes and catalysts for glycerol carbonate production via direct and indirect use of CO2

Glycerol can be utilised as a renewable feedstock in several chemical reactions, including carbonation, carbonylation, transesterification, and oxidation. Among the several conversions, the production of glycerol carbonate is environmentally most attractive, as it also utilises CO2 as the carbon source, as C1 feedstock, a key to accelerate the pursuit of decarbonization and the net-zero goals. The glycerol carbonate production can be divided into two main pathways i.e., direct and indirect route based on the utilisation of CO2. There has been much interest in the direct conversion of glycerol with molecular CO2, due to its potential for sustainability and ecological advantages. Moreover, this process could be directly minimising CO2 levels in atmosphere. The indirect pathways involve the utilisation of CO2 as a source for the synthesis of reactants, for instance organic carbonates and urea. These reactants are employed as raw materials in the process of glycerol carbonate production. It is important to note that each reaction route has its own set of advantages and drawbacks. However, the important factor for all processes lies in the high catalytic performance of the suitable catalyst and the optimal reaction conditions to enhance the yield of glycerol carbonate. This review aims to evaluate the recent progress made on the catalyst design and process conditions to produce glycerol carbonate via both the direct and indirect reaction pathways. In each route, the catalytic systems based on the heterogenous catalysts, the reaction condition and catalytic performance are considered. Finally, suggested perspectives for the future direction in glycerol carbonate production focusing on the utilisation of molecular CO2 are presented

Recent advances in catalyst design for carboxylation using CO₂ as the C1 feedstock

Carbon dioxide is ideal for carboxylation reactions as a renewable and sustainable C1 feedstock and has significant recognition owing to its low cost, non-toxicity, and high abundance. To depreciate the environmental concentration of CO2, which causes the greenhouse gas effect, developing new catalytic protocols for organic synthesis in CO2 utilization is of great importance. This review focuses on carboxylation reactions using CO2 as a C1 feedstock to synthesize value-added functionalized carboxylic acids and their corresponding derivatives via catalytically generated allyl metal intermediates, photoredox catalysis, and electrocatalysis with a focus on recent developments and opportunities in catalyst design for carboxylation reactions. In this article, we describe recent developments in the carboxylation of C–H bonds, alkenes, and alkynes using CO2 as the C1 source for various reactions under different conditions, as well as the potential direction for the further development of CO2 utilization in organic synthesis

Novel Ionic Liquid Synthesis of Bimetallic Fe–Ru Catalysts for the Direct Hydrogenation of CO₂to Short Chain Hydrocarbons

The selective hydrogenation of CO2 for the production of net-zero fuels and essential chemical building blocks is a promising approach to combat climate change. Key to this endeavor is the development of catalysts with high activity and selectivity for desired hydrocarbon products in the C2–C5 range. The process involves a two-step reaction, starting with the reverse water–gas shift (RWGS) reaction and proceeding to the Fischer–Tropsch reactions under high pressure. Understanding the catalyst features that control the selectivity of these pathways is crucial for product formation, as well as identifying morphological changes in the catalysts during the reaction to optimize their performance. In this study, an innovative method for synthesizing iron–ruthenium bimetallic catalysts is introduced, capitalizing on the synergistic effects of these metals as active phases. This method leverages ionic liquids as solvents, allowing for the precise and uniform distribution of active metal phases. Advanced characterizations and extensive catalytic tests have demonstrated that the use of ionic liquids outperformed traditional colloid-based techniques, resulting in superior selectivity for target hydrocarbons. The success of this inventive approach not only advances the field of CO2 hydrogenation catalysis, but also represents a significant stride towards sustainable e-fuel production

Sustainable lignin‐based polyols as promising thermal energy storage materials

Six lignin-based polyols (LBPs) have been prepared by cationic ring opening polymerization of an oxirane in the presence of an organosolv lignin in tetrahydrofuran (THF) as reaction media and co-monomer. The prepared LBPs have been characterized and tested for the first time as phase change materials (PCMs) for thermal energy storage (TES) at low temperature. It was found a strong influence of the LBPs composition on their performance to storage thermal energy. Thus, LBPs with higher THF wt% content and lower oxirane/THF mass ratio exhibit the highest latent heats. Furthermore, a clear inversely proportional trend between the oxirane/THF mass ratio and the melting temperatures of the prepared LBPs was noticed. Among the prepared LBPs, the highest obtained latent heat was 53.7 J/g demonstrating the potential application of lignin as feedstock for PCMs preparation. To the best of our knowledge, this is the first time that a biomass derived PCM based on lignin has been studied and considered for TES applications at low temperature. LBPs show energetic solid–liquid transitions that point out their promising potential as bio-PCMs. This work paves the way to introduce new bio-based PCMs from lignin in TES systems, for example, in a more sustainable construction sector