Non-adiabatic Ring Polymer Molecular Dynamics in the Phase Space of the SU(N) Lie Group

We derive the non-adiabatic ring polymer molecular dynamics (RPMD) approach in the phase space of the SU(N) Lie Group. This method, which we refer to as the spin mapping non-adiabatic RPMD (SM-NRPMD), is based on the spin-mapping formalism for the electronic degrees of freedom (DOFs) and ring polymer path-integral description for the nuclear DOFs. Using the Stratonovich-Weyl transform for the electronic DOFs, and the Wigner transform for the nuclear DOFs, we derived an exact expression of the Kubo-transformed time-correlation function (TCF). We further derive the spin mapping non-adiabatic Matsubara dynamics using the Matsubara approximation that removes the high frequency nuclear normal modes in the TCF and derive the SM-NRPMD approach from the non-adiabatic Matsubara dynamics by discarding the imaginary part of the Liouvillian. The SM-NRPMD method has numerical advantages compared to the original NRPMD method based on the MMST mapping formalism, due to a more natural mapping using the SU(N) Lie Group that preserves the symmetry of the original system. We numerically compute the Kubo-transformed position auto-correlation function and electronic population correlation function for three-state model systems. The numerical results demonstrate the accuracy of the SM-NRPMD method, which outperforms the original MMST-based NRPMD. We envision that the SM-NRPMD method will be a powerful approach to simulate electronic non-adiabatic dynamics and nuclear quantum effects accurately

Room temperature synthesis of non-isocyanate polyurethanes (NIPUs) using highly reactive N-substituted 8-membered cyclic carbonates

There is a growing interest to develop green synthetic pathways towards industrially relevant polymers such as polyurethanes without the use of toxic and dangerous isocyanate monomers. The most promising route towards non-isocyanate polyurethanes (NIPUs) is the aminolysis of dicyclic carbonates derived from renewable resources. Although, cyclic carbonates of 5- and 6-members have been successfully proposed, aminolysis of these compounds requires the use of high temperatures to obtain high conversions and subsequently high molecular weight NIPUs. Indeed, these cyclic carbonates do not allow the achievement of high molecular weight NIPUs using low reactive diamines analogous to two of the most industrially relevant aliphatic diisocyanates. Herein, we report a (bis) N-substituted 8-membered cyclic carbonate that could be prepared from naturally abundant epoxides, diamines and dimethyl carbonate using sustainable chemical routes. This N-substituted 8 membered cyclic carbonate appeared to be much more reactive than the smaller 5- and 6-membered cyclic carbonates. Due to this increased reactivity, we obtained high molecular weight NIPUs using a variety of diamines, including industrially relevant hindered aliphatic diamines, such as 5-amino-1,3,3-trimethylcyclohexanemethylamine (IPDA) and 4,4’-methylenebis(cyclohexylamine). The synthesis of NIPUs was demonstrated at room temperature without the need for any additional catalyst. Altogether, this paper shows that (bis) N-substituted 8-membered cyclic carbonates are ideal starting materials for the synthesis of sustainable non-isocyanate polyurethanes (NIPUs).he authors would like to thank the European Commission for its financial support through the projects Renaissance-ITN 289347, OrgBIO-ITN 607896 and SUSPOL-EJD 642671. Haritz Sardon gratefully acknowledges financial support from MINECO through project SUSPOL and FDI 16507. Yi Yan Yang gratefully acknowledges financial support from Institute of Bioengineering and Nanotechnology (Biomedical Research Council, Agency for Science, Technology and Research, Singapore). We are also thankful for the technical and human support provided by IZO-SGI SGIker of UPV-EHU and European funding (ERDF and ESF)

Poly(hydroxy acids) derived from the self-condensation of hydroxy acids: from polymerization to end-of-life options

[EN] Poly(hydroxy acids) have been gaining increasing attention in the search for novel sustainable materials to replace petrochemical polymers in packaging applications. Poly(hydroxy acids) are polyesters that are obtained using hydroxy acids as the starting materials, which are derived from renewable resources and biowaste. These biopolymers have attracted a lot of attention since some of them will be in the near future competitive in price to polyolefins, show excellent mechanical and barrier properties, and can be potentially recycled by physical and chemical routes. Most of the current poly(hydroxy acids) are mainly prepared by ring-opening polymerization (ROP) of cyclic monomers derived from hydroxy acids. However, their direct polymerization has received much less attention, while one of the advantages of hydroxy acids resides in the presence of an electrophile and a nucleophile in a single molecule that makes them ideal A-B type monomers for self-condensation. This review focuses on the preparation of poly(hydroxy acids) by the self-condensation polymerization of hydroxy acids. Moreover, their end-of-life options are also evaluated considering not only their biodegradability but also their potential to be chemically recycledThe authors thank the European Commission (EC) for financial support through the project SUSPOL-EJDH2020-ITN-2014-642671 and the Spanish Ministry of Science and Innovation (MICI) through the projects RTI2018-097249-B-C21, MAT2017-83373-R, and MAT-2016-78527-P. S. Torres-Giner also acknowledges MICI for his Juan de la Cierva-Incorporacion contract (IJCI-2016-29675) and the financial support received during his stay at the Institute for Polymer Materials (POLYMAT)Gabirondo, E.; Sangroniz, A.; Etxeberria, A.; Torres-Giner, S.; Sardon, H. (2020). Poly(hydroxy acids) derived from the self-condensation of hydroxy acids: from polymerization to end-of-life options. Polymer Chemistry. 11(30):4861-4874. https://doi.org/10.1039/D0PY00088DS48614874113

EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

New challenges in the synthesis of non-isocyanate polyurethanes

212 p.Entre todos los materiales plásticos, los poliuretanos (PU) representan el sexto polímero más utilizado en el mundo; se sintetizan industrialmente mediante la reacción entre un diol y un diisocianato, en presencia de un catalizador metálico y un disolvente orgánico. Sin embargo, esta síntesis presenta importantes problemas ambientales y de salud. Con el fin de reemplazar estos compuestos tóxicos, los avances en este campo han dado lugar a una serie de procesos libres de isocianato. Sin embargo, estos procesos tienen que enfrentar muchos desafíos (propiedades físicas, masas molares, reacciones secundarias, etc.) para competir con los poliuretanos convencionales. Por lo tanto, parte de este manuscrito está dedicado al estudio de la influencia de los organocatalizadores, como TBD o P4, no solo sobre la cinética de polimerización de la aminólisis de carbonatos bisciclicos, sino también sobre la estructura y propiedades de las UP resultantes. . Posteriormente, y con el fin de limitar el uso de compuestos orgánicos volátiles, se obtuvieron dispersiones acuosas de PU libres de isocianato llevando a cabo: 1) el proceso de acetona a la aminólisis de carbonatos bisciclicos y 2) la polimerización interfacial a la policondensación de lineal dicarbonatos con diaminas.Polymat LCPO :Laboratoire de Chimie des Polymères Organiques SUSPO

New challenges in the synthesis of non-isocyanate polyurethanes

212 p.Entre todos los materiales plásticos, los poliuretanos (PU) representan el sexto polímero más utilizado en el mundo; se sintetizan industrialmente mediante la reacción entre un diol y un diisocianato, en presencia de un catalizador metálico y un disolvente orgánico. Sin embargo, esta síntesis presenta importantes problemas ambientales y de salud. Con el fin de reemplazar estos compuestos tóxicos, los avances en este campo han dado lugar a una serie de procesos libres de isocianato. Sin embargo, estos procesos tienen que enfrentar muchos desafíos (propiedades físicas, masas molares, reacciones secundarias, etc.) para competir con los poliuretanos convencionales. Por lo tanto, parte de este manuscrito está dedicado al estudio de la influencia de los organocatalizadores, como TBD o P4, no solo sobre la cinética de polimerización de la aminólisis de carbonatos bisciclicos, sino también sobre la estructura y propiedades de las UP resultantes. . Posteriormente, y con el fin de limitar el uso de compuestos orgánicos volátiles, se obtuvieron dispersiones acuosas de PU libres de isocianato llevando a cabo: 1) el proceso de acetona a la aminólisis de carbonatos bisciclicos y 2) la polimerización interfacial a la policondensación de lineal dicarbonatos con diaminas.Polymat LCPO :Laboratoire de Chimie des Polymères Organiques SUSPO

Nouveaux défis dans la synthèse de polyuréthanes sans isocyanates

Parmi tous les plastiques, les polyuréthanes (PUs) représentent la sixième classe de polymères la plus utilisée au monde. Ils sont synthétisés industriellement par réaction entre un diol et un diisocyanate, en présence d'un catalyseur métallique et d’un solvant organique.Néanmoins, cette synthèse présente d’importants problèmes environnementaux et de santé.Afin de s’affranchir de ces composés toxiques, les progrès dans ce domaine ont conduit à un certain nombre de procédés sans isocyanates. Néanmoins, ces procédés doivent faire face à de nombreux défis (propriétés physiques, masses molaires, réactions secondaires, etc.), afin de concurrencer les polyuréthanes classiques. Par conséquent, une partie de ce manuscrit est dédiée à une étude rationnelle de l'influence de catalyseurs organiques, tels que le TBDou P4, non seulement sur la cinétique de polymérisation de l’aminolyse de carbonates biscycliques,mais aussi sur la structure et les propriétés des PUs résultants. Par la suite, et afin de limiter l’utilisation de composés organiques volatiles, des dispersions aqueuses de polyuréthanes sans isocyanates ont été obtenues en adaptant : 1) le procédé acétone à l’aminolysis de carbonates bis-cycliques et 2) la polymérisation interfaciale à la polycondensation de dicarbonates linéaires avec des diamines.Among all plastic materials, polyurethanes (PUs) represent the 6th most popularly usedpolymers in the World. They are industrially synthesized by the reaction between a diol and adiisocyanate, in the presence of a metal catalyst and an organic solvent. Nevertheless, thissynthesis presents important environmental and health problems. In order to replace thesetoxic compounds, advances in this field have led to a number of isocyanate-free processes.However, these processes have to face many challenges (physical properties, molarmasses, side reactions, etc.), in order to compete with conventional polyurethanes.Therefore, part of this manuscript is dedicated to a rational study of the influence oforganocatalysts, such as TBD or P4, not only on the polymerization kinetics of the aminolysisof bis-cyclic carbonates, but also on the structure and properties of the resulting PUs.Subsequently, and in order to limit the use of volatile organic compounds, aqueousdispersions of non-isocyanate PUs were obtained by adapting: 1) the acetone process to theaminolysis of bis-cyclic carbonates and 2) the interfacial polymerization to thepolycondensation of linear dicarbonates with diamines

Theories and simulations of molecular reactive collisions for primordial chemistry

Dans cette thèse, nous présentons l'analyse de la dynamique réactionnelle de systèmes triatomiques d'intérêt pour la chimie primordiale. Les simulations ont principalement été réalisées en utilisant le formalisme des trajectoires quasi-classiques (approche QCT) pour lesquelles un code a été développé. Celui-ci présente l'avantage de pouvoir déterminer des constantes de vitesse d'état-à-état avec un coût numérique raisonnable et pour une grande gamme de températures. Nous avons montré que les résultats QCT sont très appropriés notamment dans la gamme des énergies de collision élevées en réalisant un nombre limité de calculs quantiques dépendants du temps (méthode MCTDH). Un très grand nombre de constantes de vitesses (~ 300000) a été déterminé pour les systèmes H3, H2D caractéristiques de processus directs. Notre étude a par ailleurs révélé l'importance du processus de dissociation pour le régime des hautes températures (T > 10^3 K). Les nouvelles données cinétiques permettront de contraindre les abondances moléculaires de H2 et HD et ainsi de fournir des fonctions de refroidissement fiables pour l'étude de la dynamique d'effondrement des nuages moléculaires précurseurs des premières étoiles. Ces nouvelles données peuvent également être employées pour des régions du milieu interstellaire où les états moléculaires d'énergie interne élevée sont suffisamment peuplés (régions PDR ou chocs de type C). Nous présentons aussi la dynamique de réactions indirectes des systèmes H2D+ et HeH2+. Pour ces processus qui peuvent être caractérisés par un complexe intermédiaire à longue durée de vie, nous avons montré qu'une méthode quantique approchée (méthode RPMD), peut être très efficace pour déterminer la constante de vitesse thermalisée et représente ainsi une approche d'intérêt pour de nombreuses réactions en astrochimie.In this PhD we present the analysis of the reactive dynamics of triatomic systems of interest for the primordial chemistry. Simulations have been mainly done using the quasi-classical trajectory formalism (QCT approach) for which a code has been developed. iT has the advantage of being able to determine the state-to-state rate constants with a low numerical cost and a large temperature domain. We have shown that the QCT results are very reliable in the high collision energy domain by realizing a limited number of time dependent quantum method calculations (MCTDH method). A huge number of rate constants (~300000) has been determined for the systems H3, H2D, typical of direct processes. Our study also revealed the importance of dissociation for high temperature regime (T > 10^3 K). The new kinetic data will permit to constrain the molecular abundances of H2 and HD, hence giving reliable cooling functions for the dynamics study of collapse of the molecular clouds precursor of the first stars. Those data could be employed in interstellar medium in regions where high internal energy molecular states are relevantly populated (PDR or C-type shocks). We present the indirect reaction dynamics of the systems H2D+ and HeH2+. For those processes that can be characterized by a long lifetime intermediate complex, we have shown that a approximated quantu method (RPMD method) can be very efficient to determine thermalized rate constants and represents an interesting approach for many reactions in astrochemistry

Nouveaux défis dans la synthèse de polyuréthanes sans isocyanates

Among all plastic materials, polyurethanes (PUs) represent the 6th most popularly usedpolymers in the World. They are industrially synthesized by the reaction between a diol and adiisocyanate, in the presence of a metal catalyst and an organic solvent. Nevertheless, thissynthesis presents important environmental and health problems. In order to replace thesetoxic compounds, advances in this field have led to a number of isocyanate-free processes.However, these processes have to face many challenges (physical properties, molarmasses, side reactions, etc.), in order to compete with conventional polyurethanes.Therefore, part of this manuscript is dedicated to a rational study of the influence oforganocatalysts, such as TBD or P4, not only on the polymerization kinetics of the aminolysisof bis-cyclic carbonates, but also on the structure and properties of the resulting PUs.Subsequently, and in order to limit the use of volatile organic compounds, aqueousdispersions of non-isocyanate PUs were obtained by adapting: 1) the acetone process to theaminolysis of bis-cyclic carbonates and 2) the interfacial polymerization to thepolycondensation of linear dicarbonates with diamines.Parmi tous les plastiques, les polyuréthanes (PUs) représentent la sixième classe de polymères la plus utilisée au monde. Ils sont synthétisés industriellement par réaction entre un diol et un diisocyanate, en présence d'un catalyseur métallique et d’un solvant organique.Néanmoins, cette synthèse présente d’importants problèmes environnementaux et de santé.Afin de s’affranchir de ces composés toxiques, les progrès dans ce domaine ont conduit à un certain nombre de procédés sans isocyanates. Néanmoins, ces procédés doivent faire face à de nombreux défis (propriétés physiques, masses molaires, réactions secondaires, etc.), afin de concurrencer les polyuréthanes classiques. Par conséquent, une partie de ce manuscrit est dédiée à une étude rationnelle de l'influence de catalyseurs organiques, tels que le TBDou P4, non seulement sur la cinétique de polymérisation de l’aminolyse de carbonates biscycliques,mais aussi sur la structure et les propriétés des PUs résultants. Par la suite, et afin de limiter l’utilisation de composés organiques volatiles, des dispersions aqueuses de polyuréthanes sans isocyanates ont été obtenues en adaptant : 1) le procédé acétone à l’aminolysis de carbonates bis-cycliques et 2) la polymérisation interfaciale à la polycondensation de dicarbonates linéaires avec des diamines

New challenges in the synthesis of non-isocyanate polyurethanes

Parmi tous les plastiques, les polyuréthanes (PUs) représentent la sixième classe de polymères la plus utilisée au monde. Ils sont synthétisés industriellement par réaction entre un diol et un diisocyanate, en présence d'un catalyseur métallique et d’un solvant organique.Néanmoins, cette synthèse présente d’importants problèmes environnementaux et de santé.Afin de s’affranchir de ces composés toxiques, les progrès dans ce domaine ont conduit à un certain nombre de procédés sans isocyanates. Néanmoins, ces procédés doivent faire face à de nombreux défis (propriétés physiques, masses molaires, réactions secondaires, etc.), afin de concurrencer les polyuréthanes classiques. Par conséquent, une partie de ce manuscrit est dédiée à une étude rationnelle de l'influence de catalyseurs organiques, tels que le TBDou P4, non seulement sur la cinétique de polymérisation de l’aminolyse de carbonates biscycliques,mais aussi sur la structure et les propriétés des PUs résultants. Par la suite, et afin de limiter l’utilisation de composés organiques volatiles, des dispersions aqueuses de polyuréthanes sans isocyanates ont été obtenues en adaptant : 1) le procédé acétone à l’aminolysis de carbonates bis-cycliques et 2) la polymérisation interfaciale à la polycondensation de dicarbonates linéaires avec des diamines.Among all plastic materials, polyurethanes (PUs) represent the 6th most popularly usedpolymers in the World. They are industrially synthesized by the reaction between a diol and adiisocyanate, in the presence of a metal catalyst and an organic solvent. Nevertheless, thissynthesis presents important environmental and health problems. In order to replace thesetoxic compounds, advances in this field have led to a number of isocyanate-free processes.However, these processes have to face many challenges (physical properties, molarmasses, side reactions, etc.), in order to compete with conventional polyurethanes.Therefore, part of this manuscript is dedicated to a rational study of the influence oforganocatalysts, such as TBD or P4, not only on the polymerization kinetics of the aminolysisof bis-cyclic carbonates, but also on the structure and properties of the resulting PUs.Subsequently, and in order to limit the use of volatile organic compounds, aqueousdispersions of non-isocyanate PUs were obtained by adapting: 1) the acetone process to theaminolysis of bis-cyclic carbonates and 2) the interfacial polymerization to thepolycondensation of linear dicarbonates with diamines