Deciphering the Self-Catalytic Mechanisms of Polymerization and Transesterification in Polybenzoxazine Vitrimers.

The use of internal catalysts has emerged as a pivotal design principle to facilitate dynamic exchanges within covalent adaptable networks (CANs). Polybenzoxazines, specifically, have shown considerable potential in generating vitrimers through thermally induced transesterification reactions catalyzed internally by tertiary amines. This study aims to investigate the chemical complexities of transesterification reactions within benzoxazine vitrimers.

Bio-Based Bisbenzoxazines with Flame Retardant Linker.

This work explores the strategy of incorporating a highly substituted reactive flame retardant into a benzoxazine moiety. For this purpose, a DOPO-based flame retardant received a chain extension via reaction with ethylene carbonate. It was then reacted with phloretic acid to obtain a diphenol end-capped molecule, and further reacted with furfurylamine and paraformaldehyde to obtain a benzoxazine monomer via a Mannich-like ring closure reaction.

Multipurpose Processing Additives for Silica/Rubber Composites: Synthesis, Characterization, and Application.

Processing additives are a special group of chemicals included in rubber formulations to facilitate the flowability of the resultant compounds. Their addition generally affects the cured properties of the subsequent rubber composites, and fine-tuning of the compound formulation is therefore required. In this work, an attempt has been made to address this issue through the preparation of new bio-based processing additives capable of promoting the mixing of the rubber compound while at the same time enhancing mechanical properties following curing.

Unique Carbonate-Based Single Ion Conducting Block Copolymers Enabling High-Voltage, All-Solid-State Lithium Metal Batteries.

Safety and high-voltage operation are key metrics for advanced, solid-state energy storage devices to power low- or zero-emission HEV or EV vehicles. In this study, we propose the modification of single-ion conducting polyelectrolytes by designing novel block copolymers, which combine one block responsible for high ionic conductivity and the second block for improved mechanical properties and outstanding electrochemical stability. To synthesize such block copolymers, the ring opening polymerization (ROP) of trimethylene carbonate (TMC) monomer by the RAFT-agent having a terminal hydroxyl group is used.

Semiquantitative Solid-State NMR Study of the Adsorption of Soybean Oils on Silica and Its Significance for Rubber Processing.

Soybean oil (SBO) is a renewable material used as an alternative to conventional petroleum-derived oils in the processing of rubber composites. Upon chemical modifications, such as epoxidation, its performance in the processing of rubber can be significantly improved, as indicated by a considerable reduction of the mixing energy. Although it has been hypothesized that hydrogen bonding between functional groups (e.

An Investigation on the Thermally Induced Compatibilization of SBR and α-Methylstyrene/Styrene Resin.

The miscibility between two polymers such as rubbers and performance resins is crucial to achieve given targeted properties in terms of tire performances. To this aim, α-methylstyrene/styrene resin (poly(αMSt--St)) are used to modify the viscoelastic behavior of rubbers and to fulfill the requirements of the final applications. The initial aim of this work was to understand the influence of poly(αMSt--St) resins blended at different concentrations in a commercial styrene-butadiene rubber (SBR).

Synthesis of Novel Benzoxazines Containing Sulfur and Their Application in Rubber Compounds.

This work reports the synthesis and successful use of novel benzoxazines as reinforcing resins in polyisoprene rubber compounds. For this purpose, three new dibenzoxazines containing one (4DTP-fa) or two heteroatoms of sulfur (3DPDS-fa and 4DPDS-fa) were synthesized following a Mannich condensation reaction. The structural features of each benzoxazine precursor were characterized by H and C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and Raman.

Sustainable Esterification of a Soda Lignin with Phloretic Acid.

In this work, a sustainable chemical process was developed through the Fischer esterification of Protobind lignin, a wheat straw soda lignin, and phloretic acid, a naturally occurring phenolic acid. It aimed at increasing the reactivity of lignin by enhancing the number of unsubstituted phenolic groups via a green and solvent-free chemical pathway. The structural features of the technical and esterified lignins were characterized by complementary spectroscopic techniques, including H, C, P, and two-dimensional analysis.

Development of plasticized edible films from Opuntia ficus-indica mucilage: A comparative study of various polyol plasticizers.

Mucilage polysaccharide was extracted from Opuntia ficus-indica cladodes (Cactaceae) and its composition was determined by sugar analysis using HPLC-RID and its structural features were elucidated by FTIR and H and C NMR. Films from the extracted mucilage were loaded at 40% (w/w) with glycerol, sorbitol, PEG 200 or PEG 400. The physical, thermal, mechanical and barrier properties of the obtained films were investigated.

Exploration of cardanol-based phenolated and epoxidized resins by size exclusion chromatography and MALDI mass spectrometry.

Cardanol and cardanol derivatives are among the most important biobased materials currently investigated in green chemistry, as renewable and promising building blocks in lieu of traditional raw materials from non renewable resources, in particular owing to the olefinic linkages on the C15 alkyl side-chain. Despite the increasing interest they arouse, analytical chemistry dedicated to cardanol and associated resins has been rarely reported in the literature, found even poorer when dealing with chromatography and mass spectrometry. In this work, a thorough molecular characterization was conducted using matrix assisted laser desorption ionization (MALDI) mass spectrometry, size exclusion chromatography (SEC), and SEC-MALDI coupling to gain insights into the composition of phenolated, epoxidized, and epoxidized phenolated cardanol.

Synthesis of clicked imidazolium-containing biosourced copolymers and application in carbon nanotube dispersion.

New polyesters incorporating a variable quantity of imidazolium rings along the backbone are synthesized by Huisgen 1,3-dipolar cycloaddition ("click" reaction). Subsequently, the imidazolium-grafted copolymers reveal an efficient dispersing ability toward the carbon nanotubes (CNTs) through supramolecular interactions in organic media. Interestingly, these compounds offer a simple and reliable strategy to control the quantity of dispersed CNTs as a function of imidazolium content.

Poly(ethylene oxide)-b-poly(L-lactide) diblock copolymer/carbon nanotube-based nanocomposites: LiCl as supramolecular structure-directing agent.

This work relies on the CNT dispersion in either solution or a polymer matrix through the formation of a three-component supramolecular system composed of PEO-b-PLLA diblock copolymer, carbon nanotubes (CNTs), and lithium chloride. According to a one-pot procedure in solution, the "self-assembly" concept has demonstrated its efficiency using suspension tests of CNTs. Characterizations of the supramolecular system by photon correlation spectroscopy, Raman spectroscopy, and molecular dynamics simulations highlight the charge transfer interaction from the CNTs toward the PEO-b-PLLA/LiCl complex.

Design of cross-linked semicrystalline poly(ε-caprolactone)-based networks with one-way and two-way shape-memory properties through Diels-Alder reactions.

Cross-linked poly(ε-caprolactone) (PCL)-based polyesterurethane (PUR) systems have been synthesized through Diels-Alder reactions by reactive extrusion. The Diels-Alder and retro-Diels-Alder reactions proved to be useful for enhancing the molecular motion of PCL-based systems, and therefore their crystallization ability, in the design of cross-linked semicrystalline polymers with one-way and two-way shape-memory properties. Successive reactions between α,ω-diol PCL (PCL(2) ), furfuryl alcohol, and methylene diphenyl 4,4'-diisocyanate straightforwardly afforded the α,ω-furfuryl PCL-based PUR systems, and subsequent Diels-Alder reactions with N,N-phenylenedimaleimide afforded the thermoreversible cycloadducts.

Reversible positioning at submicrometre scale of carbon nanotubes mediated by pH-sensitive poly(amino-methacrylate) patterns.

The selective adsorption of carbon nanotubes (CNTs) on a pH-reversible PDMAEMA patterned gold surface is presented. In acidic conditions, a selective CNTs adsorption onto the polymer brushes is obtained due to ammonium-π interactions. The reversible behavior was shown by successive treatments in both alkaline and acidic solutions with CNTs.