Resorcinol Diglycidyl Ether Research Articles

Exploring strategies for valorizing wood processing waste: advancing sustainable, fully lignocellulosic biocomposites

This study presents the design and synthesis of bio-composites exhibiting high properties, wherein both the matrix and filler originate from wood biomass. Notably, no additional hardener compounds or treatments/modifications of the lignocellulosic filler were employed. Thermosetting materials were developed by homopolymerizing a bio-based aromatic epoxy monomer, the resorcinol diglycidyl ether (RDGE), with different percentages, from 1 wt% to 30 wt% of natural wood processing side-product, such as spruce bark powder (SB), which was used as such without additional treatments and modifications. The DSC analyses revealed enhanced reactivities with the bio-filler content, resulting in a reduced reaction temperature range and maximum reaction temperature. These findings provide evidence of the chemical interaction between the functional groups from spruce bark and the epoxides groups. The obtained fully based lignocellulosic materials show high E' values from 2.4 GPa to 2.5–3.5 GPa (glassy state) and from 64 MPa to 99–156 MPa in the rubbery region. The damping factor of the bio-composites with 1–10 wt% SB have shown an increase of the α transition temperature from 92 °C to 94–97 °C. The excellent filler/matrix interface and optimal adhesion between them were confirmed by SEM analysis.

Dendritic bifunctional nanotraps inside SBA‐15 for highly efficient removal of selected nonsteroidal anti‐inflammatory drugs from wastewater

AbstractLarge‐pore mesoporous SBA‐15 materials were functionalized with dendritic bifunctional ligands to achieve efficient adsorption of nonsteroidal anti‐inflammatory drugs (NSAIDs) in aqueous solution mainly through a combination of anion‐exchange ability of quaternary ammonium cations and π‐π interaction capability of oxygen activated phenyls. The synthesis of such a dendritic ligand starts from propylamine on SBA‐15 followed by consecutive amine‐epoxy reactions with resorcinol diglycidyl ether (RDGE) and methylamine, and then amination of terminal epoxy with trimethylamine. The results from Fourier‐transform infrared spectroscopy, nitrogen adsorption–desorption measurements and elemental analysis reveal that the bifunctional dendritic nanotraps have been created successfully inside the mesochannels of SBA‐15 (DNT@SBA‐15). Adsorption kinetics for NSAIDs was very rapid following a pseudo‐second‐order kinetic model, and adsorption isotherms were fitted well by the Langmuir isotherm model. Notably, DNT@SBA‐15 demonstrated remarkably high adsorption capacities for NSAIDs, with maximum values of 1037.3 mg g−1 for ibuprofen, 821.3 mg g−1 for naproxen and 781.3 mg g−1 for diclofenac at pH 7.0. The adsorption was presumed to be governed by a dual‐interaction mechanism including electrostatic and van der Waal's interactions. This study demonstrates that the developed dendritic anion‐exchanger can be a promising material for removing NSAIDs adsorption from environmental water.

Chitosan as a Polyfunctional Crosslinker for a Renewable-Based Resorcinol Diglycidyl Ether

Chitosan is an abundant renewable biopolymer, insufficiently valorized, which is suitable for the development of sustainable and fully biobased materials. In this study, we combined it with the resorcinol diglycidyl ether, a biobased monoaromatic diepoxide. Formulations with a high chitosan content of up to 44 wt % were investigated and showed high reactivity and appropriate intervals of polymerization, ranging from 75 to 125 or 155 °C. The in situ Fourier transform infrared (FTIR) spectroscopy analysis confirmed that the two compounds reacted via an anionic polymerization mechanism combined with polyaddition reactions, proving that the chitosan acts as a polyfunctional crosslinker. The obtained thermoset resins have tan δ values ranging between 79 and 73 °C and storage moduli increasing with chitosan content (E′ ∼3.5–4.2 GPa), together with high crosslinking densities (15.65–27 mmol·cm–3).

Hot-lithography 3D printing of biobased epoxy resins

The introduction of Hot Lithography has opened new perspective in the field of additive manufacturing especially with regard to high viscous formulations. The access to elevated temperature in the 3D printing process not only reduce the viscosity of resin but it allows to achieve higher curing kinetics and degree of conversion. Therefore, it is possible to process new type of monomers which are not reactive enough at room temperature towards UV-curing expanding the formulation design and selection to the 3D-printing of a broader range of epoxy-based formulations. With regard to climate change and the limitation of fossil resources, new needs arise for the origin of the materials. In this view, we investigated the use of two bio-based epoxy monomers (furandimethanol diglycidyl ether (FDE) and resorcinol diglycidyl ether (RDE)) in Hot Lithography 3D printing. Moreover, we compared the performance of the bio-based resins with a commercial fossil-based one, the 1,4-cyclohexanedimethanol diglycidyl ether (CDE). The photocuring process was fully characterized by means of real-time NIR/photorheology and photo-DSC analysis. The thermo-mechanical properties of the final thermosets were investigated by DMTA and tensile test. Finally, the 3D printing of complex shapes was carried out to demonstrate the possibility to obtain arbitrary self-standing shapes. • Hot-lithography 3D-printing of bio-based epoxy resin. • Photocuring of Furan-dimethanol diglycidyl ether epoxy resin. • Photocuring of 1,4-cyclohexanedimethanol diglycidyl ether.

Self- blowing non-isocyanate polyurethane foam: Synthesis, characterization and properties

Polyurethane (PU) foams are inevitable for many applications from comfort materials or energy saving to aerospace. Today, greener routes for their production have gained thoughtful attention among the scientific community by avoiding mainly the use of toxic isocyanates. An easily scalable process for the realization of self-blown isocyanate-free PU (poly (hydroxy urethane)-PHU) foams by exploiting suitable amines and cyclic carbonates is demonstrated in this work. The foaming is attributed to the release of CO2, from the reaction of cyclic carbonate of resorcinol diglycidyl ether (RDGCC) with amine terminated oligomeric phenyl hydroxy amine (AOPHA), where a parallel reaction of the hydroxyl groups and amino groups with the cyclic carbonate groups are competing during polymerization and culminate in poly (hydroxy urethane) foam. The released gas was confirmed as CO2 from GC–MS and temperature dependent FTIR. The realized flexible PHU foam is thermally stable (>250 ℃) with adhesive strength between Al-Al as 1.5 to 2.0 MPa, and with a closed cell structure possessing a density of 480 kg/m3.

Lipase-Catalyzed Epoxy-Acid Addition and Transesterification: from Model Molecule Studies to Network Build-Up.

Commercially available lipase from Pseudomonas stutzeri (lipase TL) is investigated as a biocatalyst for the formation of an acid-epoxy chemical network. Molecular model reactions are performed by reacting 2-phenyl glycidyl ether and hexanoic acid in bulk, varying two parameters: temperature and water content. Characterizations of the formed products by 1H NMR spectroscopy and gas chromatography-mass spectrometry combined with enzymatic assays confirm that lipase TL is able to simultaneously promote acid-epoxy addition and transesterification reactions below 100 °C and solely the acid-epoxy addition after denaturation at T > 100 °C. A prototype bio-based chemical network with β-hydroxyester links was obtained using resorcinol diglycidyl ether and sebacic acid as monomers with lipase TL as catalyst. Differential scanning calorimetry, attenuated total reflection, and swelling analysis confirm gelation of the network.

Durable anti-oil-fouling superhydrophilic membranes for oil-in-water emulsion separation

Abstract Marine mussel-inspired polydopamine (PDA) coatings show excellent hydrophilicity and substrate-independent adhesion ability, but low stability, especially in a harsh environment such as strong acid or strong base, significantly restricts their applications. In this work, we prepare a novel superhydrophilic and underwater superoleophobic coating based on a modified PDA. Diglycidyl resorcinol ether (DGRE) polyethyleneimine (PEI) and iron ions were incorporated into PDA to strengthen the cross-linking and coating durability. By using three chemically inert hydrophobic membranes, polytetrafluoroethylene (PTFE), poly(vinylidene fluoride), and polypropylene, as substrates, we showed that PDA/PEI/DGRE-coated membranes had a water contact angle (CA) of 0° and underwater oil CA above 157°, and their underwater oil SAs were <7°. The coating is durable against both physical and chemical damages including ultrasound and heat treatments, as well as acid/alkaline etching. After ultrasound treatment in water for 60 min, and heating treatment for 3 h, or acid/alkaline etching for 3 h, the coated PTFE membrane still showed water CAs of ∼0° in air and underwater oil CAs of ∼150°. The coated membranes can efficiently separate oil-in-water emulsions, even in strong acid and base environments. The water flux was above 1500 L m−2 h−1, and the oil rejection was above 99%.

Design of macroporous photo-cationically cured resorcinol-based epoxy resins coupled to a solid template technique

This paper presents for the first time an eco-friendly combination of cationic photopolymerization and the solid template technique to obtain macroporous epoxy resins from resorcinol diglycidyl ether (RDGE) with defined cell size and distribution. The polymerization was performed by cationic polymerization under UV irradiation in the presence of NaCl particles template sintered through the spark plasma sintering process (SPS). After removal of NaCl by water, a porous material with interconnected pores was obtained. The influence of processing parameters, i.e., reactant contents, UV irradiation time, and post-curing conditions on the reticulation achievement and the thermomechanical behavior have been pointed out. Mechanical, physical, acoustic and morphological properties were deeply investigated. For instance, the specific compressive modulus is of 50.9 MPa cm3.g−1 for a density of 0.224 g.cm−3 and the glass transition is around 137 °C, which makes this system an interesting alternative for sustainable building materials.

Hydrothermal Carbon as Reactive Fillers to Produce Sustainable Biocomposites with Aromatic Bio-Based Epoxy Resins.

Thiswork is focused on the development of sustainable biocomposites based on epoxy bioresin reinforced with a natural porous material (hydrochar, HC) that is the product of spruce bark wastes subjected to hydrothermal decomposition. To identify the influence of hydrochar as a reinforcing material on the designed composites, seven formulations were prepared and tested. An aromatic epoxy monomer derived from wood biomass was used to generate the polymeric matrix, and the formulations were prepared varying the filler concentration from 0 to 30 wt %. The reactivity of these formulations, together with the structural, thermal, and mechanical properties of bio-based resin and biocomposites, are investigated. Surprisingly, the reactivity study performed by differential scanning calorimetry (DSC) revealed that HC has a strong impact on polymerization, leading to an important increase in reaction enthalpy and to a decrease of temperature range. The Fourier Transform Infrared Spectroscopy (FT-IR) investigations confirmed the chemical bonding between the resin and the HC, while the dynamic mechanical analysis (DMA) showed increased values of crosslink density and of storage moduli in the biocomposites products compared to the neat bioresin. Thermogravimetric analysis (TGA) points out that the addition of hydrochar led to an improvement of the thermal stability of the biocomposites compared with the neat resorcinol diglycidyl ether (RDGE)-based resin (T5% = 337 °C) by ≈2–7 °C. Significantly, the biocomposites with 15–20 wt % hydrochar showed a higher stiffness value compared to neat epoxy resin, 92SD vs. 82SD, respectively.

Multiscale Network Structure Analysis by Time Domain 1H DQ NMR and DMA of Resorcinol Diglycidyl Ether‐Jeffamine Matrices

AbstractEpoxy‐amine networks have found their way in everyday and technical applications for the past several years. Special attention on biosourced monomers has increased for sustainable development applications. This work investigates the influence of the chemical structure on the thermomechanical behavior of biosourced epoxy‐based matrices through a multiscale approach. Resorcinol Diglycidyl Ether (RE) was hardened with Jeffamines (molecular weights MW≈230, 500, 800, and 2000 g mol−1). Bisphenol A Diglycidyl Ether (DGEBA) was also studied for comparison. By combining Dynamic Mechanical Analysis (DMA) and Time Domain Nuclear Magnetic Resonance (NMR), it was proven that the difference in the chemical structure of Jeffamines yielded matrices with distinct network morphologies, influencing the behavior of the matrices. A linear relationship between the crosslink densities probed by DMA and Time NMR was observed, demonstrating a direct influence of the network structure at the molecular level with the obtained macroscopic properties. It was demonstrated that physical entanglements in these matrices act as mechanical reinforcements. This work shows a novel and robust multiscale experimental approach allowing to understand key structure‐property relationships for epoxy‐amine thermosets.

Study of the Compatibilization Effect of Different Reactive Agents in PHB/Natural Fiber-Based Composites

Fiber–matrix interfacial adhesion is one of the key factors governing the final properties of natural fiber-based polymer composites. In this work, four extrusion reactive agents were tested as potential compatibilizers in polyhydroxylbutyrate (PHB)/cellulose composites: dicumyl peroxide (DCP), hexamethylene diisocyanate (HMDI), resorcinol diglycidyl ether (RDGE), and triglycidyl isocyanurate (TGIC). The influence of the fibers and the different reactive agents on the mechanical properties, physical aging, and crystallization behavior were assessed. To evaluate the compatibilization effectiveness of each reactive agent, highly purified commercial cellulose fibers (TC90) were used as reference filler. Then, the influence of fiber purity on the compatibilization effect of the reactive agent HMDI was evaluated using untreated (U_RH) and chemically purified (T_RH) rice husk fibers, comparing the results with the ones using TC90 fibers. The results show that reactive agents interact with the polymer matrix at different levels, but all compositions showed a drastic embrittlement due to the aging of PHB. No clear compatibilization effect was found using DCP, RDGE, or TGIC reactive agents. On the other hand, the fiber–polymer interfacial adhesion was enhanced with HMDI. The purity of the fiber played an important role in the effectiveness of HMDI as a compatibilizer, since composites with highly purified fibers showed the greatest improvements in tensile strength and the most favorable morphology. None of the reactive agents negatively affected the compostability of PHB. Finally, thermoformed trays with good mold reproducibility were successfully obtained for PHB/T_RH/HMDI composition.

Synthesis of non-isocyanate poly(hydroxyurethane)s (NI-PHUs) using diglycidyl ethers

In this study, we synthesized non-isocyanate poly(hydroxyurethane)s (NI-PHUs) via the polyaddition of bis(cyclic carbonate)s and diamines. Bis(cyclic carbonate)s were prepared by reacting resorcinol diglycidyl ether and neopentyl glycol diglycidyl ether with CO2. NI-PHUs were obtained through the reaction of the bis(cyclic carbonate)s with either an aliphatic or a cycloaliphatic diamine. The identities of the synthesized products were confirmed via 1H NMR and FT-IR spectroscopy. The glass transition temperatures (Tgs) of the NI-PHUs were higher when resorcinol diglycidyl ether was used to synthesize the bis(cyclic carbonate) instead of neopentyl glycol diglycidyl ether. The NI-PHUs prepared with isophorone diamine had significantly higher Tgs than those prepared with 1,4-diaminobutane.

Resorcinol-Based Epoxy Resins Hardened with Limonene and Eugenol Derivatives: From the Synthesis of Renewable Diamines to the Mechanical Properties of Biobased Thermosets

Synthesis of fully eco-friendly thermosets based on renewable resorcinol diglycidyl ether (RE) hardenered with different biobased diamines having aliphatic, cyclic, or aromatic backbones were prepa...

Polyhydroxybutyrate Bioresins with High Thermal Stability by Cross-linking with Resorcinol Diglycidyl Ether.

The development of sustainable materials by employing natural and nontoxic resources has been attracting much attention over the previous years. In this work, we discuss for the first time the chemical combination between resorcinol diglycidyl ether (RDGE), an aromatic biobased thermosetting monomer, and polyhydroxybutyrate (PHB), a bioderived and biodegradable thermoplastic polyester. By this combination, we aimed to associate the high thermal stability of RDGE with a toughening effect by the aliphatic chains of PHB. The investigations on the mechanism of the cross-linking reaction and on the structural connectivity between the two components were realized by Fourier transform infrared (FTIR) and NMR spectroscopies. We found that the epoxide polymerization catalyzed by tertiary amines triggers the formation of crotonyl species by polyhydroxybutyrate cleavage. Two-dimensional NMR experiments show that polyhydroxybutyrate fragments covalently bind as side chains to the rigid aromatic network of the epoxide frame. The cross-linking between the two systems entails the formation of new ester and ether bonds. The obtained structures show a network homogeneity confirmed by a single Tg, from 85 to 47 °C, as a function of the formulation, and tan δ values from 87 to 53 °C. The combination of the two comonomers showed a positive effect. The PHB increased the toughness of RDGE-based thermosets, improving the material elasticity by increasing the chain length between the cross-links. An important result of this study is the high thermal stability of RDGE/PHB bioresins, with the T5% varying between 330 and 310 °C as a function of the PHB ratio.

An Eco-Effective Soybean Meal-Based Adhesive Enhanced with Diglycidyl Resorcinol Ether.

Soybean meal-based adhesive is a good wood adhesive mainly due to its renewable, degradable, and environmentally friendly features. To improve the enhancement efficiency for adhesives, diglycidyl resorcinol ether (DRE) containing a benzene ring and flexible chain structure was used as an efficient cross-linker to enhance the adhesive in the study. The physicochemical properties of adhesives, the dry shear strength, and wet shear strength of plywood were measured. Results suggested that DRE reacted with the functional groups of soybean meal adhesive and formed a cross-linking network during hot press process in a ring-opening reaction through a covalent bond. As expected, compared to adhesive control, the soybean meal adhesive with 4 wt% DRE incorporation showed a significant increment in wet shear strength by 227.8% and in dry shear strength by 82.7%. In short, soybean meal adhesive enhanced with DRE showed considerable potential as a wood adhesive for industrial applications.

Photocurable bulk epoxy resins based on resorcinol derivative through cationic polymerization

AbstractBio‐sourced epoxy resins from resorcinol diglycidyl ether (RDGE) have been obtained by using cationic photopolymerization under UV‐light exposure. The photoinduced bulk resin samples were characterized by three‐point bending tests, dynamic mechanical analysis, as well as differential scanning calorimetry analysis, and thermogravimetric analysis. The influence of processing parameters, that is, reactant contents, UV irradiation time, and postcuring conditions on the thermomechanical behavior has been pointed out. For instance, the flexural modulus of the most performing materials reaches 4.1 GPa with the flexural strength and the glass‐transition temperature of around 105 MPa and 99°C, respectively. Interestingly, our optimized protocol has led to the synthesis of new bio‐based materials with more valuable thermal and mechanical properties than those of thermocured materials obtained from petroleum‐based commercial epoxy resins. Focus has been given on processing parameters to optimize the final properties of the material and to open an interesting alternative for sustainable building materials.

Synthesis and application of a novel 5-hydroxymethyl resorcinol diglycidyl ether-terminated polyurethane

Epoxy resin containing active hydroxymethyl group, 5-hydroxymethyl resorcinol diglycidyl ether, was synthesized to produce 5-hydroxymethyl resorcinol diglycidyl ether-terminated polyurethane (ETPU1000). The synthesized epoxy resin is a small monomer molecule, and no polymer is produced during the synthesis process. A monomer contains one hydroxyl group, and more flexible polyurethane segments can be introduced into the main chain when synthesizing the epoxy-terminated polyurethane. The synthesis process of ETPU1000 was investigated by FT-IR spectroscopy. The disappearance of NCO peak in the FT-IR spectrum showed that diisocyanate has completely reacted to form ETPU1000. Then, a series of epoxy cured systems were prepared by changing the mass ratio of ETPU1000 and the diglycidyl ether of bisphenol A (DGEBA), and cured with 4,4'-diaminodiphenyl methane (DDM). The effect of the content of ETPU1000 on the thermal properties, mechanical properties and fracture morphology of epoxy cured systems were investigated. The results showed that when the DGEBA/ETPU1000 blends with 75 wt% ETPU1000, impact strength of the cured systems reached 29.6 kJ·m−2, which significantly increased by 176.6% compared to that of neat epoxy. Scanning electron microscopy (SEM) was used to observe the fracture surfaces of cured DGEBA/ETPU1000 blends, which showed obvious ductile fracture characteristics.

Co-catalyst and Metal-free CO2 Fixation into Cyclic Carbonates: COPs to the Rescue

The non-redox fixation of CO2 in cyclic and polymeric carbonates is regarded as one of the most promising technologies for small-scale CO2 utilization. Yet, most heterogeneous catalysts reported to date require the use of co-catalysts, harsh reaction conditions, and non-base metals. In this issue of Chem, Yavuz and coworkers report the one-step synthesis of a new covalent organic polymer that circumvents these issues.

Hyperbranched mixed-mode anion-exchange polymeric sorbent for highly selective extraction of nine acidic non-steroidal anti-inflammatory drugs from human urine

This paper describes the poly(divinylbenzene) (PDVB) supported synthesis of quaternized hyperbranched macromolecules (QHMs) and its use as a highly selective, high-capacity mixed-mode anion-exchange (MAX) sorbent. In detail, the aminated PDVB support was firstly synthesized by copolymerization of divinylbenzene and 2-(diethylamino)ethyl methacrylate via Pickering emulsion polymerization. The QHMs were then grafted on PDVB by a divergent synthesis involving consecutive reactions of resorcinol diglycidyl ether with methylamine (N, N-dimethylethanolamine for terminal epoxides), which brought in a high density of quaternary ammonium functionalities. The changes of specific surface area (SBET), pore volume and ion exchange capacity (IEC) with generation number reveal that the QHMs have been grown successfully within the large meso-channels of the porous aminated PDVB. The best compromise between the SBET, pore volume and IEC was obtained at the 4th generation (G4). Due to the highest IEC (0.47 meq/g), the G4-QHMs was successfully applied for mixed-mode solid phase extraction (SPE) of acidic non-steroidal anti-inflammatory drugs (NSAIDs). An efficient approach based on the mixed-mode SPE coupled with HPLC-UV was developed for highly selective extraction and cleanup of nine NSAIDs (tolmetin, TLM; ketoprofen, KEP; naproxen, NAP; flurbiprofen, FLB; diclofenac, DIC; indomethacin, INM; ibuprofen, IBP; mefenamic acid, MFA; tolfenamic acid, TFA) in human urine samples. Under the optimized conditions, the method exhibited satisfactory recoveries ranging from 81.9% to 104.0% with relative standard deviation (RSD) values below 8.5%, good sensitivity (0.004–0.009 μg mL−1 limit of detection) and good linearity (coefficient of determination, R2 > 0.997, 0.01–0.2 μg mL−1 for NAP, 0.05–1.0 μg mL−1 for FLB, DIC, INM, MFA, TFA, 0.1–2.0 μg mL−1 for TLM, KEP, IBP). The hyperbranched MAX sorbent is superior to Oasis HLB and comparable to Oasis MAX in obtaining clean chromatographic profiles. Our results demonstrate the potential application of the hyperbranched MAX for complex sample analysis.

Antibacterial and antioxidant photoinitiated epoxy co-networks of resorcinol and eugenol derivatives

In this study, we used photo-induced cationic reactions to design bio-based crosslinked co-networks from resorcinol diglycidyl ether (R) and an eugenol derivative (epoxy eugenol EE) synthesized by nucleophilic substitution. The aim of this work is to prepare new UV-cured co-networks thanks to the cationic polymerization of the epoxides with a covalent immobilization of the eugenol derivative (EE) as antioxidant and antibacterial agent to investigate the impact of the proportion of this one on biological activities. Moreover, the antibacterial and antioxidant properties of the networks were studied in vitro against two pathogenic bacteria strains: Escherichia coli and Staphylococcus aureus and the DPPH method respectively. The results had shownon the one hand a promising anti-adherence forthe both strains without any diffusion of the eugenol derivative which will allow potential applications of these networks for anti-bacterial adhesion and, on the other hand an anti-oxidant activity.