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In this study, a novel polymerizable ionic liquid monomer (ILM) based on a bisimidazolium salt was first synthesized in order to substitute bisphenol A diglycidyl ether (DGEBA) as a starting material, avoiding the use of highly toxic Bis-imidazolium and carcinogenic bisphenol A and epichlorohydrin products. From ionic liquid such a new epoxy monomer, an epoxy network was prepared from the copolymerization between the bisimidazolium salt and isophorone diamine (IPD). Subsequently, the properties of this novel ionic liquid based polymer network have been investigated in terms of polyaddition reaction kinetics as well as the architecture-properties, i.e., thermal stability, surface properties, and the mechanical performances. In addition, for the first time, molecular dynamics simulations were combined with experimental measurements in order to confirm the experimental data as well to be able to predict the physical behaviors from their architecture, molecular scale structuration, and thermomechanical properties of the resulting network. Finally, the substitution of DGEBA by this ILM led to a thermosetting polymer with high thermal stability (up to 450 degrees C), hydrophobic behavior (21 mJ m(-2)), and promising mechanical performances (1.7 GPa) including a shape memory behavior.

Self-healing polymers based on dynamic crosslinkers have drawn rapidly increasing interest over the last decade. Here, a self-healable epoxy network with exchangeable disulfide bonds was synthesized by polymerizing two epoxies with an aromatic amine containing a disulfide bond. The bisphenol A diglycidyl ether (DGEBA) and poly(ethylene glycol) diglycidyl ether (DER736) were used as rigid and soft components, respectively. The crosslinking densities of studied polymers decreased with the increasing amount of DER736, resulting in the lower glassy temperature and weaker mechanical strength. The dynamic covalent network character of disulfide bond and its low active energy were also investigated through stress relaxation experiments at various temperatures. The self-healing performance of healable epoxy resins with varied flexibility was measured by tensile tests. The tensile strength of a full-cut sample was restored to 84% (13 MPa) of the initial values (16 MPa) at moderate temperature. Its healed fracture strain was up to 505%. Moreover, the effect of healing time and temperature on the self-healing properties was also studied. A model was proposed to investigate the self-repairing efficiency evolution with healing time, suggesting that hydrogen bonds mainly contributed to the initial sticking or interfacial adhesion while disulfide links and chain interdiffusion assisted time dependent reformation of networks to restore the original mechanical strength.

Producing the next generation of thermoset polymers from renewable sources is an important sustainability goal. Hydrogenolysis of pinewood lignin was scaled up for the first time from lab scale to a 50 L pilot-scale reactor, producing a range of depolymerized lignin oils under different conditions. These lignin hydrogenolysis oils were glycidylated, blended with bisphenol A diglycidyl ether, and cured to give epoxy thermoset polymers. The thermal and mechanical properties of the epoxy polymers were assessed by differential scanning calorimetry, thermogravimetric analysis, flexural testing, and dynamic mechanical thermal analysis. Replacing up to 67% of the bisphenol A epoxy with the lignin oil epoxies resulted in cured epoxy polymers with improvements of up to 25% in flexural stiffness and strength. Considerable scope exists in simplifying and scaling up the hydrogenolysis process to produce depolymerized lignins that can substitute established petrochemicals in the quest for renewable high-performance thermoset polymers.

The role of bisphenol-A diglycidyl ether (BADGE)—a weakly interacting, low molecular weight additive on crystallization kinetics, morphology and spherulite growth of semi-crystalline thermoplastic- poly(trimethylene terephthalate) (PTT) is quantitatively evaluated. Blends of PTT with different loadings of BADGE were prepared by melt blending. Weak secondary interactions between BADGE and PTT influenced the crystallization kinetics of PTT. This gives rise to concentration-dependent changes in spherulite morphology, crystallization kinetics and stereochemical conformation of PTT. BADGE behaved as a nucleating agent/plasticizer for PTT depending on its loading and changed the conformational distribution of PTT thereby facilitating chain mobility, along with diffusion and attachment of chain segments to crystal nuclei and growth faces. Crystallization kinetics and glass transition studies were carried out using differential scanning calorimetry, while spherulite growth rate was followed using polarized optical microscope equipped with hot stage, and the microphase structure evaluated using small-angle X-ray scattering studies.

Although polycarbonate (PC) materials are well known to have poor adhesion to other surfaces, few studies have been conducted on the improvement of their adhesive properties via surface chemical functionalization. Herein, we report the enhancement in the adhesion properties of PC by adapting two silane coupling agents, namely (3-glycidoxypropyl) methyldiethoxysilane (GPTMS) and (3-aminopropyl) trimethoxysilane (APTMS), on the surface. We tested the adhesion with an epoxy-based adhesive consisting of bisphenol A diglycidyl ether (BADGE) and trientine (trien). The chemical interaction between the amine groups of the hardener (trien) and the epoxy rings of an epoxy-functionalized PC (PC-GPTMS) sample surface was observed with X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. We found that the amine-functionalized PC (PC-APTMS) can also form crosslinked polymeric structures with the BADGE after curing. Compared to the bare PC, an increase in the shear strength of up to 168% and 163% was observed from the PC-GPTMS and PC-APTMS, respectively. In contrast, the ultraviolet-ozone (UVO) and O2 plasma-treated samples showed a negligible increase in adhesion strength. These results strongly suggest that the chemical functionalization of PC substrates with coupling agents significantly enhances the adhesion properties of PCs.

The objective of this research was to investigate the development of novel bio-based epoxides from microalgae Nannochloropsis gaditana lipids, which were extracted using hexane, petroleum ether and methanol:chloroform (2:1 v/v). In lipids epoxidation, conversions of 90.9%, 99.3% and 87.6% of epoxidized microalgae lipids (EML) were obtained for lipids extracted using these solvents. The mechanical properties of EML in blends with bisphenol A diglycidyl ether (DGEBA) show that the elongation at break increases and tensile strength decreases. Moreover, an increasing in the final maximum degradation temperature and a decrease in the glass transition temperature (Tg) were observed in the blends.

Isocyanate-capped chains of poly(teramethylene oxide) (PTMO) are synthesized by the reaction of hexamethylene diisocyanate and polytetramethylene glycol in 2 : 1 molar ratio. Then, the resulting telechelic macrochains are covalently grafted to silica nanoparticles via formation of urethane linkages. Amine-functionalized silica nanoparticles coated by soft and flexible shell of poly(teramethylene oxide) are obtained after hydrolysis of the remaining isocyanate end groups. These organo-silica nanoparticles are homogeneously loaded into diglycidyl ether of bisphenol A epoxy resin in two different contents, i.e. 5 and 10 wt %. Alongside isophorone diamine as the main hardener of the resin, amine groups of the poly(teramethylene oxide)-grafted nanoparticles allow them to participate effectively in the hardening process. The resulting epoxy/silica nanocomposites are thoroughly characterized by field emission-scanning electron microscopy, fourier transform infrared spectroscopy, and X-ray diffraction. Dynamic mechanical thermal analysis showed that the filler considerably enhances storage moduli of the resulting nanocomposites. However, probing the thermal properties of the epoxy/silica nanocomposites by thermogravimetric analysis and differential thermal analysis showed that the filler has no significant effect on the heat stabilities and thermal phase transitions.

In this study, we report an integrated theoretical and experimental investigation of an epoxy polymer matrix containing Au nanoparticles. We performed molecular dynamics simulations to elucidate the atomic-level interactions between the nanoparticles and the epoxy polymer. Our simulation results reveal that the hardener molecules adopted extended conformations on the Au nanoparticle surface, while the epoxy monomer, bisphenol A diglycidyl ether, adopted more complex molecular configurations at the Au interface. The addition of Au nanoparticles into the epoxy polymer increased the glass transition temperature, likely due to the reduced chain flexibility of the polymer matrix. Our predicted and measured mechanical tests suggest that the nanoparticles had a negligible effect on the mechanical properties due to the low concentrations used. Our computational protocol provides a platform to reveal the molecular-level interactions of nanoparticles and thermoset polymers, enabling the future design of multi-functional nanocomposites with superior properties.

A persistent challenge in predictive molecular modeling of thermoset polymers is to capture the effects of chemical composition and degree of crosslinking (DC) on dynamical and mechanical properties with high computational efficiency. We established a new coarse-graining (CG) approach that combines the energy renormalization method with Gaussian process surrogate models of the molecular dynamics simulations. This allows a machine-learning informed functional calibration of DC-dependent CG force field parameters. Taking versatile epoxy resins consisting of Bisphenol A diglycidyl ether combined with curing agent of either 4,4-Diaminodicyclohexylmethane or polyoxypropylene diamines, we demonstrated excellent agreement between all-atom and CG predictions for density, Debye-Waller factor, Young's modulus and yield stress at any DC. We further introduce a surrogate model enabled simplification of the functional forms of 14 non-bonded calibration parameters by quantifying the uncertainty of a candidate set of high-dimensional and flexible calibration functions. The framework established provides an efficient methodology for chemistry-specific, large-scale investigations of the dynamics and mechanics of epoxy resins., new version: minor updates to the force field and general formatting after peer review

Polyamide (PA) thin-film composite (TFC) membranes are commonly applied in reversed osmosis (RO) and nanofiltration (NF) applications due to their thin, dense top-layer, and high selectivity. Recently, the conventional organic phase (i.e., hexane) during interfacial polymerization (IP) was replaced by less toxic ionic liquids (ILs) which led to excellent membrane performances. As the high price of most ILs limits their up-scaling, the potential use of inexpensive Aliquat was investigated in this study. The thin-film composite (TFC) membranes were optimized to remove flavor compounds, i.e., ethyl acetate (EA) and isoamyl acetate (IA), from a fermentation broth. A multi-parameter optimization was set-up involving type of support, reaction time for IP, water content of Aliquat, and concentration of both monomers m-phenylenediamine (MPD) and trimesoylchloride (TMC). The membranes prepared using Aliquat showed similar fluxes as those prepared from a reference IL 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([C4mpyr][Tf2N]) but with better EA and IA retentions, even better than for a commercial RO membrane (GEA type AF). Finally, the recently introduced epoxide-curing of Bisphenol A diglycidyl ether (BADGE) with 1,6-hexanediamine (HDA) was investigated using Aliquat as organic phase. It is the first time this type of IP was performed in combination with an IL as organic phase. The resulting membrane was used in the filtration of a 35 µM Rose Bengal (RB) in 20 wt% dimethylformamide/ water (DMF/H2O) feed mixture. A well-crosslinked poly(β-alkanolamine) film was obtained with a &gt, 97% retention.

The depletion of limited petroleum resources used for the fabrication of epoxy resins calls for the development of biomass-based epoxides as promising alternatives to petroleum-derived epoxides. However, it is challenging to obtain an epoxy resin with both high lignin content and excellent mechanical performance. Herein, a 4-dimethylaminopyridine (DMAP)-lignin epoxide with a certain epoxy value and a small molecular weight is obtained by the catalysis of DMAP for the macromolecular lignin. It was discovered that compared to the prepared composite resin of benzyltriethylammonium chloride (BTEAC)-lignin epoxide, there is a better low-temperature storage modulus for the DMAP-lignin epoxide resin and its composite resins with high-biomass contents, and higher tensile strength for its composite resins. In particular, the DMAP-lignin epoxide/ bisphenol A diglycidyl ether (BADGE) (DB) composite resin with DMAP-lignin epoxide replacement of 80 wt% BADGE, containing up to 58.0 wt% the lignin epoxide, exhibits the tensile strength of 76.3 ± 3.2 MPa. Its tensile strength is 110.2% of BTEAC-lignin epoxide/BADGE (BB) composite resins and is comparable to that of petroleum-based epoxy resins. There are good application prospects for the DB composite resin in the engineering plastics, functional composite, grouting, and other fields.

Epoxy resins containing multi-wall carbon nanotubes (MWCNTs) have proven to be suitable for manufacturing promising self-sensing materials to be applied in the automotive and aeronautic sectors. Different parameters concerning morphological and mechanical properties of the hosting matrices have been analyzed to choose the most suitable system for targeted applications. Two different epoxy precursors, the tetrafunctional tetraglycidyl methylene dianiline (TGMDA) and the bifunctional bisphenol A diglycidyl ether (DGEBA) have been considered. Both precursors have been hardened using the same hardener in stoichiometric conditions. The different functionality of the precursor strongly affects the crosslinking density and, as a direct consequence, the electrical and mechanical behavior. The properties exhibited by the two different formulations can be taken into account in order to make the most appropriate choice with respect to the sensing performance. For practical applications, the choice of one formulation rather than another can be performed on the basis of costs, sensitivity, processing conditions, and most of all, mechanical requirements and in-service conditions of the final product. The performed characterization shows that the nanocomposite based on the TGMDA precursor manifests better performance in applications where high values in the glass transition temperature and storage modulus are required.

Polymers commonly have low thermal conductivity in the range of 0.1–0.2 W·m−1·K−1, which is a limiting factor for their usage in the course of continuously increasing miniaturization and heat generation in electronic applications. Two strategies can be applied to increase the transport of phonons in polymers: (i) the embedment of thermally conductive inorganic materials and (ii) the involvement of aromatic units enabling anisotropy by π–π stacking. In this study, the thermal conductivity of resins based on bisphenol A diglycidyl ether BADGE and 1,2,7,8-diepoxyoctane DEO was compared. DEO can be derived from pseudo-pelletierine, which is contained in the bark of the pomegranate tree. The epoxy compounds were cured with isophorone diamine IPDA, o-dianisidine DAN, or mixtures of the both diamines. Notably, isophorone diamine is derived from isophorone of which the latter naturally occurs in cranberries. The formulations were produced without filler or with 5 wt.-% of SiO2 nanoparticles. Significantly enhanced thermal conductivity in the range of 0.4 W·m−1·K−1 occurs only in DEO-based polymer networks that were cured with DAN (and do not contain SiO2 fillers). This observation is argued to originate from π–π stacking of the aromatic units of DAN enabled by the higher flexibility of the aliphatic carbon chain of DEO compared to that of BADGE. This assumption is further supported by the facts that significantly improved thermal conductivity occurs only above the glass-transition temperature and that nanoparticles appear to disrupt the π–π stacking of the aromatic groups. In summary, it can be argued that the bisphenol-free epoxy/amine resin with an epoxy compound derivable from natural resources shows favorably higher thermal conductivity in comparison to the petrol-based epoxy/amine resins.

Novel optical, electronic, and chemical properties emerge when few metal atoms held together by metal-metal bonds, these ultra-small pieces of metals are also called quantum clusters (QCs).Silver quantum clusters (AgQCs) protected by thiolates, the diameter of one QC is around 1 nm, termed as one of the ultra-small sized materials belongs to the size category of fullerenes. In the present research, we presented the effectiveness of these ultra-small silver clusters for enhancing the fracture toughness (KIC) property of bisphenol A diglycidyl ether (DGEBA) epoxy composite. Enhancing the fracture toughness play an important role in composite material’s designs. The little amount of QCs (0.06 wt%) addition to epoxy polymer substantially enhanced the KIC of DGEBA epoxy composite by 22%. Strong reinforcing influences of these ultra-small nanofillers on the microstructure of epoxy nanocomposites is clearly evident by the X-ray diffraction (XRD) and scanning electron microscopy (SEM) examinations.

An NP-GLIDE coating contained in matrix nanometer-sized pools of a grafted lubricating ingredient for dewetting enablement and lubricant poly(dimethyl siloxane) (PDMS) was used in this study. Furthermore, a silicone-infused NP-GLIDE (SINP-GLIDE) coating contained in its matrix nanopools of a silicone oil mixture that was stabilized by the grafted PDMS chains. Also, the coating was a pre-SLIPS (slippery liquid-infused porous surface) when the diameter of the PDMS-stabilized silicone oil pools became comparable with the wavelength of visible light. In this study, NP-GLIDE, SINP-GLIDE, and pre-SLIPS coatings were prepared from curing bisphenol A diglycidyl ether (DGEBA) and poly(glycidyl methacrylate)-graft-poly(dimethyl siloxane) (PGMA-g-PDMS) using Jeffamine in the absence or presence of a silicone oil mixture. The SLIPS coatings were obtained after additionally dosing the surfaces of the pre-SLIPS films with silicone oil. A pre-SLIPS formulation was also cast onto a rough substrate to yield a superhydrophobic coating. Besides the preparation of the various coatings, herein, we report the optical and de-wetting properties of the different coatings and phase diagrams describing the relationship between the coating types with PDMS and their silicone oil mass fractions. The results of this comparative study facilitate the choice of coating for targeted applications.

To reduce crude oil consumption and the corresponding environmental impact, the use of sustainable resources has recently attracted much attention. Herein, a low-viscosity and efficient tannin-based epoxy resin (MTEBPE) was prepared using liquefaction of renewable tannin (MTEBP) and epichlorohydrin feedstocks, and then used as modifier to enhance the toughness and strength of fossil fuel-based bisphenol A diglycidyl ether (DGEBA). The results show that the mechanical properties of the thermosets could be significantly improved after blending with MTEBPE; in particular, the tensile, flexural, and impact strengths, as well as the elongation at break of 5 wt% MTEBPE/DGEBA increased by 35.8%, 45.4%, 243.8%, and 81.6%, respectively, compared with those of neat DGEBA. The enhanced toughness and strength of the epoxy thermosets can be attributed to the combined effect of the crosslinking density, intramolecular cavities, and branched structure of MTEBPE. More importantly, the temperatures corresponding to 5% and 50% weight loss (T5% and T50%, respectively) and the char yield at 600 °C of the 5 wt% MTEBPE/DGEBA thermosets were basically the same as those of neat DGEBA. In addition, the thermosets exhibited excellent chemical resistance, also to alkali and organic solvents. In brief, MTEBPE, a multifunctional bio-based epoxy derived from waste bark, shows great application advantages in coatings, adhesives, and functional materials.

Objective: The objective of the study was to assess surface roughness, microhardness, colorstability, water sorption and water solubility of polymethyl methacrylate (PMMA) denture base resinreinforced with inorganic {silanized ZrO2}, organic {Bisphenol A diglycidyl ether dimethacrylate(Bis-GMA)+Triethylene glycol dimethacrylate (TEGDMA)+Polyethylene glycol dimethacrylate(PEGDMA)} and hybrid {silanized ZrO2+Bis-GMA+ TEGDMA} Nanofibers.Materials and Methods: The study was divided into four groups according to the addednanofibers (6wt%) to heat curing PMMA denture base material; Control group: PMMA denturebasematerial without reinforcing nanofibers, Inorganic group: PMMA denture-base material withsilanized ZrO2 nanofibers, Organic nanofibers group: PMMA denture-base material with Bis-GMA/TEGDMA/PEGDMA nanofibers and, Hybrid nanofibers group: PMMA denture-base material withsilanized ZrO2/Bis-GMA/TEGDMA nanofibers. For each group, 10 specimens were prepared andtested for surface roughness, microhardness, water sorption and water solubility. For each group11 specimens were prepared and tested for color stability. Surface roughness was measured byoptical method. Digital Microhardness tester was used to measure Vickers microhardness. Colorstability was evaluated according to ISO/FDIS 20795-1 and ISO 7491, using a Portable ReflectiveSpectrophotometer. Water sorption (WSP) and water solubility (WSL) were performed accordingto ISO/FDIS 20795-1. One-way ANOVA was used for comparison between groups and Post-Hoctest (Tukey’s tests) was used for multiple comparisons. P-value different.Results: One-way ANOVA revealed insignificant differences between the studied groups insurface roughness (p=0.168) and color stability (p=0.806). Significant differences were found in microhardness (p=0.000), WSP (p=0.000) and WSL (p=0.000). Post-Hoc (Tukey’s test) revealedthat: 1) microhardness means of nanofibers-reinforced groups were markedly significantly higherthan control group (p=0.000). 2) WSP of organic nanofibers reinforced group was significantlylower than that of control (p=0.008), hybrid (p=0.001) and inorganic (p=0.000) groups that werenot significantly different from each other (p≥0.243). 3) WSL of ZrO2 nanofibers reinforced groupwas significantly higher than control, organic, and hybrid groups (p=0.000). However, the controlgroup was not significantly different from organic (p=0.992) and hybrid (P=0.018) groups. Organicgroup was significantly lower than hybrid group(p=0.009).Conclusions: Addition of 6% nanofibers prepared by electrospinning technique to PMMAdenture resin significantly enhanced microhardness. Surface roughness and color stability were notaffected. Water sorption was significantly reduced with organic nanofibers, but was not affected withZrO2 and hybrid nanofibers. The highest water solubility for nanofibers reinforced groups recordedin this study was (0.46±0.04μg/mm3) which is nearly one third of the ISO limit (1.6μg/mm3).

The breakdown of the polymeric component of contemporary composite dental restorative materials compromises their longevity, while leachable compounds from these materials have cellular consequences. Thus, a new generation of composite materials needed to be designed to have a longer service life and ensure that any leachable compounds are not harmful to appropriate cell lines. To accomplish this, we have developed concurrent thiol-ene-based polymerization and allyl sulfide–based addition-fragmentation chain transfer chemistries to afford cross-linked polymeric resins that demonstrate low shrinkage and low shrinkage stress. In the past, the filler used in dental composites mainly consisted of glass, which is biologically inert. In several of our prototype composites, we introduced fluorapatite (FA) crystals, which resemble enamel crystals and are bioactive. These novel prototype composites were benchmarked against similarly filled methacrylate-based bisphenol A diglycidyl ether dimethacrylate / triethylene glycol dimethacrylate (bisGMA/TEGDMA) composite for their cytotoxicity, mechanical properties, biofilm formation, and fluoride release. The leachables at pH 7 from all the composites were nontoxic to dental pulp stem cells. There was a trend toward an increase in total toughness of the glass-only-filled prototype composites as compared with the similarly filled bisGMA/TEGDMA composite. Other mechanical properties of the glass-only-filled prototype composites were comparable to the similarly filled bisGMA/TEGDMA composite. Incorporation of the FA reduced the mechanical properties of the prototype and bisGMA/TEGDMA composite. Biofilm mass and colony-forming units per milliliter were reduced on the glass-only-filled prototype composites as compared with the glass-only-filled bisGMA/TEGDMA composite and were significantly reduced by the addition of FA to all composites. Fluoride release at pH 7 was greatest after 24 h for the bisGMA/TEGDMA glass + FA composite as compared with the similarly filled prototypes, but overall the F- release was marginal and not at a concentration to affect bacterial metabolism.

An uncomplicated mode of preparing the fire retardant-hardener labeled DETA-CuSO4 (DETA – diethylenetriamine) with its subsequent incorporation into framework of epoxy resin to obtain self-extinguishing epoxy-amine composites possessing the balanced physical-mechanical properties and fire retardancy has been elaborated. The influence of the DETA-CuSO4 complex formation onto the epoxy resin curing processes has been studied by means of data of the rheological, IR spectroscopic and quantum-chemical analyses of the DGEBA–DETA–CuSO4 system (DGEBA – bisphenol A diglycidyl ether). The flammability of the epoxy-amine composites with different content of the fire retardant (0, 5, 16, and 80 mass parts) has been studied. The rate of burning of the epoxy-amine composites (DGEBA/DETA-CuSO4) containing 16 and 80 mass parts of the fire retardant is intensely depressed (their samples do not propagate flame generally), while rburn. values for samples of DGEBA/DETA and DGEBA/DETA-CuSO4(5) are equal 25.2 and 24.0 mm·min− 1, respectively. The flammability was evaluated by means of UL94 test method and according to all-Union State Standard 12.1.044-89. The smoke-formation is maximal suppressed by fire retardant (CuSO4) in the largest quantities. Physical-mechanical properties were studied by means of the measurements of surface hardness, tensile strength, water absorption, and chemical resistance.

The use of the mercaptan-functionalized bisphenol A diglycidyl ether epoxy (base material) encapsulated on glass core as matrices for metal catalysts was investigated. Here, the acquiring knowledge of recyclable palladium catalysts for organic reaction which can be mechanically separated from the reaction media and next use as a heterogeneous catalyst in large-scale industries was the most important goal. Homogeneous Pd precursor [PdCl2(PhCN)2] has been heterogenized by attaching to prepared glass-polymeric supports via ligand exchange process. Collected research results indicate that mercaptans used to cure epoxy resin can greatly affect the catalytic properties of the epoxy resin with supported palladium catalyst. The epoxy system modified with mercaptans has a few possible catalytic coordination centers especially oxygen and sulfur to which the palladium ion can be bound. It should be noted that although various concentrations of palladium complex were used, the amount of metal attached to epoxide supports remained the same, that is below the sorption capacity of the polymers. Presented new type of glass-polymer supports comparing to other used corresponding organic carriers offers several practical advantages such as morphological and chemical structure of the matrix, which affect the properties of the heterogenized catalyst in the selected organic reactions: Heck reaction and hydrogenation reaction were investigated. The catalytic activity of all formulated systems was similar to homogeneous palladium precursor PdCl2(PhCN)2. The resulting glass-polymeric matrices and heterogenized palladium catalysts were characterized by varied research techniques such as surface analysis technique (ToF–SIMS) and scanning electron microscopy with energy-dispersive X-ray analyzer (SEM-EDX). We used likewise the atomic absorption spectroscopy (AAS) method to quantify the amount of palladium loaded in the recyclable support and also the BET method to determine specific pore size distribution parameters. Furthermore, XPS spectroscopy showed information about surface structure and chemical states in the palladium-supported catalysts.

Surface modifier-free hybridization of ZrO2 nanoparticles (NPs) with epoxy-based polymers is demonstrated for the first time to afford highly transparent and refractive bulk materials. This is achieved by a unique and versatile hybridization via the one-pot direct phase transfer of ZrO2 NPs from water to epoxy monomers without any aggregation followed by curing with anhydride. Three types of representative epoxy monomers, bisphenol A diglycidyl ether (BADGE), 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexane carboxylate (CEL), and 1,3,5-tris(3-(oxiran-2-yl)propyl)-1,3,5-triazinane-2,4,6-trione (TEPIC), are used to produce transparent viscous dispersions. The resulting ZrO2 NPs are thoroughly characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and solid-state 13C CP/MAS NMR measurements. The results from DLS and TEM analyses indicate nanodispersion of ZrO2 into epoxy monomers as a continuous medium. A surface modification mechanism and the binding fashion during phase transfer are proposed based on the FT-IR and solid-state 13C CP/MAS NMR measurements. Epoxy-based hybrid materials with high transparency and refractive index are successfully fabricated by heat curing or polymerizing a mixture of monomers containing epoxy-functionalized ZrO2 NPs and methylhexahydrophthalic anhydride in the presence of a phosphoric catalyst. The TEM and small-angle X-ray scattering measurements of the hybrids show a nanodispersion of ZrO2 in the epoxy networks. The refractive index at 594 nm ( n594) increases up to 1.765 for BADGE-based hybrids, 1.667 for CEL-based hybrids, and 1.693 for TEPIC-based hybrids. Their refractive indices and Abbe's numbers are quantitatively described by the Lorentz-Lorenz effective medium expansion theory. Their transmissivity is also reasonably explained using Fresnel refraction, Rayleigh scattering, and the Lambert-Beer theories. This surface modifier-free hybridization provides a versatile, fascinating, and promising method for synthesizing a variety of epoxy-based hybrid materials.

While the hydrophobicity for a self-cleaning surface is feasibly obtained via rational designs of nanostructured materials,1-2 the longevity of coatings due to the rapid function loss and weak interface bonding and the scalability due to the limited size are not on a solid footing.3 In this article, we report the synthesis of flexible self-cleaning coating with improved mechanical and chemical stability on the basis of a new hierarchical architecture, which comprises functionalized epoxy (EP) resins and industrially available activated carbons. In parallel, a self-cleaning coating with high transparency can be obtained by replacing with oxide particles, which further expands the application fields. The strong bonding force from alkene CH3–C–CH3 and phenyl groups in bisphenol A diglycidyl ether contributes to high rigidity, high toughness, and high-temperature tolerance while the ether linkages lead to high chemical resistance.4 A greatly enhanced adhesion to substrates originates from the preferable inter...

Biobased materials are the choice of the era and hence bioepoxies are gaining potential interest as excellent substitutes for commercial Bisphenol A diglycidyl ether (DGEBA) based epoxy resins. Recent research suggests that the properties of biobased epoxies are in no way inferior to those of commercial resins and hence it may be anticipated that the bio epoxies will soon replace their commercial counterparts in almost every application. Nevertheless, the limitations of bio based resins such as low flame retardancy often diminish their utility in transportation, aerospace and electronics applications. The present review attempts to address these perceived issues of bioepoxy resins by consolidating the reports that focus on the flammability as well as thermal and fire retardancy of biobased epoxy monomers and resins, along with those of blends and composites. The review also identifies the various precursors used for the synthesis of bio epoxy resins with their characterization techniques. The classification of the various flame retardants that may be incorporated into bioepoxies has been attempted.

Coal tar epoxy (CTE) coatings promote effective protection of steel structures under critical conditions of atmosphere and immersion. However, according to the international guideline, coal tar has been reported as a mutagenic and carcinogenic compound and has been prohibited for use in countries such as the USA and Japan. Aiming to replace the use of CTE coatings, this paper proposes the use of Kraft lignin, a bio-polyphenol considered safe and obtained as waste from the pulp and paper industry, to develop a coal tar free epoxy coating. In order to promote better compatibilization with bisphenol A diglycidyl ether (DGEBA), lignin was subjected to the acetylation process. The epoxy-lignin resin was obtained by incorporating acetylated lignin into DGEBA. Three types of epoxy-lignin resin were prepared, namely: DGEBA/7.5% lignin, DGEBA/15% lignin and DGEBA/30% lignin. The chemical structure of the resin was evaluated by Fourier transform infrared spectroscopy (FTIR). For the coating preparation, the resin was cured using isophorone diamine (IPDA). The resultant thermosetting were analyzed regarding their chemical, thermal, anticorrosive and UV-blocking properties using the DGEBA and CTE coatings as reference. The anticorrosive properties of the coatings were evaluated by electrochemical impedance spectroscopy (EIS). The adhesion of the coatings was evaluated by the pull-off method (ASTM D4541). A complete absorption of UV light in the UV-A and UV-B regions was observed in the coatings add with acetylated lignin, a property very valuable in order to prevent the UV damage and the durability reduction of epoxy coatings. EIS results showed that the epoxy-lignin coatings (with 7.5 and 15% lignin content) presented modulus of impedance values comparable to the commercial coating and superior to the CTE coating, indicating the potential use of this coating as a corrosion protector.

Traditional materials are being constantly replaced by synthetic polymers, most of which are highly flammable. Epoxy resins are versatile and among the most important class of polymers, due to their multiple crosslinking capacity endowed by the oxirane ring, their applications ranging from adhesives to aeronautics. This study investigates the comparative effect of three hardeners (aromatic, cycloaliphatic, aliphatic) and the addition of an oligophosphonate on the thermal behavior and fire performance of bisphenol A diglycidyl ether semi–interpenetrating polymer networks. Networks with epoxy resin and 2% phosphorus loading were prepared. Evolved gases analyses, thermal and fire experiments were used to propose the action mode of the hardeners and oligophosphonate in the fire performance enhancement of the epoxy resin. Non–isothermal decomposition kinetics studies were conducted. The oligophosphonate in the epoxy resins promoted a significant reduction in the peak of heat release rate values (33 to 55%) in microscale combustion calorimeter experiments. A UL 94–V0 classification was achieved for the network with oligophosphonate and aromatic curing agent. The obtained results recommend the semi–interpenetrating network cured with aromatic hardener as a potential matrix for flame retardant composites or coatings.

Epoxy resin materials are spread all over the daily life with their excellent physical, mechanical, and insulating properties. However, the biologically toxic bisphenol A used in epoxy resins formulations has brought a long lasing environmental problem. It is therefore urgent to design and develop more biodegradable alternatives to mitigate the plastic menace. Lignin is an abundant biopolymer with great potential to replace petroleum-based chemicals; however, its valorization is commonly limited because of the heterogeneity. In this regard, a green and simple strategy to fabricate renewable and flexible lignin-based thermosetting epoxies with enhanced mechanical strength has been developed. Specifically, industrial biorefinery lignins are firstly fractioned through a green and simple gradient precipitation and then modified with introduced epoxy groups into the lignin macromolecule under a mild reaction condition. The cross-linking treatment facilities improved interfacial bonding forces between modified lignin fractionations and bisphenol A diglycidyl ether (BADGE) with varied contents (5–15 wt%). The fabricated cured epoxy thermosetting plastic exhibits an enhanced tensile strength (29.7%) and elongation (26.8%) as compared to those of the pure commercial BADGE polymer. We envision that the present strategy provides a new possibility for lignin valorization and design of high-performance flexible thermosetting epoxies for remarkable multifunctionality.

In this study, phenol-formaldehyde (PhF) resins, bisphenol A diglycidyl ether and 4-vinylpyridine were used for the preparation of two organic aerogels (AGs). The data showed that the organic AGs exhibited porous and functionalized structures resulting in efficient Cu(II) and Mn(II) ion removal from water sources. The AGs showed also fairly good sorption properties towards organic solvents and dyes. Combined complex permittivity and ac electrical conductivity measurements sense structural changes, indicating that AGs can also be promising sensors for the interaction of fluids interpenetrating their porous system.

Bisphenol A diglycidyl ether (DGEBA) was blended with polyetherimide (PEI) as a thermoplastic toughener for thermal stability and mechanical properties as a function of PEI contents. The thermal stability and mechanical properties were investigated using a thermogravimetric analyzer (TGA) and a universal test machine, respectively. The TGA results indicate that PEI addition enhanced the thermal stability of the epoxy resins in terms of the integral procedural decomposition temperature (IPDT) and pyrolysis activation energy (Et). The IPDT and Et values of the DGEBA/PEI blends containing 2 wt% of PEI increased by 2% and 22%, respectively, compared to those of neat DGEBA. Moreover, the critical stress intensity factor and critical strain energy release rate for the DGEBA/PEI blends containing 2 wt% of PEI increased by 83% and 194%, respectively, compared to those of neat DGEBA. These results demonstrate that PEI plays a key role in enhancing the flexural strength and fracture toughness of epoxy blends. This can be attributed to the newly formed semi-interpenetrating polymer networks (semi-IPNs) composed of the epoxy network and linear PEI.

A bio-based epoxy resin, triglycidyl ether of resveratrol (TGER), was synthesized based on the renewable resveratrol deriving from tannins. The structure and properties of TGER have been characterized by 1H NMR, 13C NMR, FTIR, GPC and viscosity measurement. Besides, systematical investigation was carried out on the curing reaction of TGER and diaminodiphenylmethane (DDM), assisted by the characterization of mechanical properties and thermal properties of cured TGER/DDM by means of differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis (DMA), flexural and impact measurement. Non-isothermal and isothermal curing analysis showed that TGER/DDM system, deriving from autocatalytic curing reaction, possessed 40 °C lower curing temperature (84 °C) than bisphenol A diglycidyl ether (DGEBA) (124 °C) and much lower activation energy than DGEBA/DDM system calculated by Kissinger equation. DMA revealed that TGER possessed high glass transition temperature (T g = 148 °C) and glassy storage modulus (2.391 GPa@23 °C). Meanwhile, TGER/DDM thermosets also exhibited good mechanical properties and heat resistance, illustrating that multi-phenol group and stilbene group of resveratrol endowed polymer with high cross-linking density and rigidness. Therefore, TGER could be a promising alternative to petroleum-based epoxy resin.

Hydroxyl-terminated liquid natural rubbers (HTNRs), prepared by the Photo-Fenton reaction, were used to modify bisphenol-A diglycidyl ether-based epoxy (DGEBA). A chemical link between HTNRs and the epoxy resin was promoted employing toluene diisocyanate. The reactions between elastomers and epoxy resin were followed by FTIR. The mechanical properties of the composites were evaluated and the microstructure was investigated using scanning electronic microscopy. The results showed that the impact resistance of HTNR-modified DGEBA was superior to that of the pure epoxy resin. For the composites with HTNR, the impact resistance increased with elastomer concentration up to 2.5 parts per hundred parts of resin. Higher concentration of HTNR resulted in larger particles which gave lower impact values.

Acetylene-terminated benzoxazines (A-BOZs) were copolymerized with bisphenol A diglycidyl ether (DGEBA) epoxy resin to improve their processibility and adhesive properties without sacrificing much thermal performance. The three possible polymerization reactions for A-BOZs/DGEBA blends were monitored by differential scanning calorimetry (DSC) analysis and Fourier transform infrared (FTIR) spectroscopy. The rheological characterization showed that a much wider processing window could be obtained for A-BOZs/DGEBA because of the dilution effect of the epoxy. The lap shear strength of A-BOZs improved significantly with the incorporation of DGEBA. Furthermore, the cured blends also showed good heat and water resistance properties and high glass transition temperature (Tg).

Different crown ethers (4-aminobenzo-15-crown-5 (4-aminobenzo-15-C5), 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (diaza-18-crown-6), tetraazacyclododecane-1,4,7,10-tetraacetic acid (H4DOTA) and tetraazacyclododecane-1,4,7,10-tetraacetamide (H2ODDA)) were used as curing agent for bisphenol A diglycidyl ether (BADGE, n = 0). The maximum enthalpy change for all systems except that formed by the epoxy resin with H4DOTA corresponds to a stoichiometric ratio, since from this value the reaction enthalpies decrease when the proportion of epoxy increases. Heteropolymerization reaction occurs in all the crown ethers. Etherification reactions occur at temperatures much lower (30 °C less) than for the porphyrin systems studied in which a second signal appears at 300 °C. The etherification is evidenced by a slight shoulder in the thermograms for H4DOTA and H2ODDA. The systems BADGE (n = 0)/4-aminobenzo-15-C5 and BADGE (n = 0)/diaza-18-crown-6 improve the thermal stability of the epoxy resin by 30 °C approximately while the improvement for BADGE (n = 0)/H4DOTA and BADGE (n = 0)/H2ODDA is about 60 °C. © 2017 Society of Chemical Industry.

Although thermal and mechanical effects of organo-silanized SiO2 nanofillers (NFs) incorporated into epoxy resins have been actively studied by many researchers, their chemical properties have rarely been reported. In this work, we investigated the chemical effects of organo-silanized SiO2 NFs on epoxy adhesives with (3-glycidoxypropyl) methyldiethoxysilane (GPTMS) and (3-aminopropyl) trimethoxysilane (APTMS)-functionalized SiO2 NFs. After curing epoxy-functionalized NF (EPOXY-NF) with triethylenetetramine (TETA) hardener, we were able to verify chemical crosslinking of the TETA hardener on EPOXY-NF with X-ray photoelectron spectroscopy, vacuum Fourier-transform infrared spectroscopy, and zeta potential analysis. Similarly, we found that after curing amine-functionalized NF (NH2-NF) with bisphenol A diglycidyl ether (DGEBA) epoxy resin, the resin was chemically crosslinked on NH2-NF as well. Finally, when we evaluated adhesion properties of adhesives composed of DGEBA resin/NH2-NF and TETA hardener/EPOXY-NF on the basis of ASTM D3163, we observed improvements in the shear strength of 79 and 49%, respectively, in comparison with bare SiO2 NF. This suggests that the chemical effects of organo-silanized SiO2 NFs indeed contribute to the adhesion properties of adhesives.

We investigated the adhesion behavior and electronic properties of an epoxy adhesive on an α-Fe 2 O 3 (0001) surface using density functional theory (DFT). We found the significant attractive interactions including cation–π interactions between the aromatic rings and the Fe 2 O 3 surface, and the electrostatic interactions between the O atom of the hydroxyl group and the Fe atoms of the Fe 2 O 3 surface. Upon adsorption of the epoxy adhesive, local density of states (LDOS) analysis reveals an overall broadening of peaks as well as band gap narrowing, indicating that changes to the electronic properties of the surface occur along with charge transfer.

A new bio-based epoxy resin (DGEDVCP) was synthesized by the glycidylation of 2,5-bis(4-hydroxy-3-methoxybenzylidene)cyclopentanone (DVCP) prepared by the crossed-aldol condensation of vanillin and cyclopentanone. The thermal and mechanical properties of DGEDVCP resins cured with renewable quercetin (QC) and guaiacol novolac (GCN) in addition to a petroleum-based phenol novolac (PN) were compared with those of bisphenol A diglycidyl ether (DGEBA) resins cured with QC, GCN and PN. Regarding the hardeners used for curing, the higher order of loss modulus (E″) peak temperature of cured products was QC > PN > GCN. The E″ peak temperatures of DGEDVCP/GCN and DGEDVCP/PN cured products were higher than and comparable to those of DGEBA/GCN and DGEBA/PN cured products, respectively. Thermal degradation temperatures of DGEDVCP-based products were slightly lower than those of DGEBA-based products. Char yields at 500 °C for DGEDVCP-based products were much higher than those of DGEBA-based products. The flexural strengths and moduli of the DGEDVCP/QC and DGEDVCP/GCN cured products were comparable to those of DGEBA/QC and DGEBA/GCN cured products, respectively.

We report on the preparation of luminescent collectors based on epoxy resins containing Coumarin 6 as fluorescent dye. Fluorescent epoxy slabs were obtained by carefully mixing from 60 to 150 ppm of the fluorophore with bisphenol A diglycidyl ether and 4,4′-methylenebis(2-methylcyclohexylamine) as curing agent. Spectroscopic (FT-IR, solid-state NMR, Raman) investigations and calorimetric analysis evidence the success of the preparation procedure in terms of slab homogeneity, fluorophore dispersibility and its role in promoting the crosslinking extent. The concentrating ability and the derived optical efficiencies of the epoxy-based collectors are determined with a properly designed set-up and result greater (∼10%) than that of poly(methyl methacrylate) concentrators with the same fluorophore and geometry. Optical efficiencies as high as 7.4% are obtained and enable the potential use of epoxy resins as bulk thermosetting materials for solar collectors.

International audience; Thermal oxidation of three epoxy resins differing by the nature of prepolymer (bisphenol A diglycidyl ether and 1,4-butanediol diglycidyl ether) and hardener (isophorone diamine and 4,7,10-Trioxa-1,13-tridecanediamine) was studied by monitoring changes in glass transition temperature using DSC. Results were discussed using the DiMarzio's approach in which parameters are estimated from an additive group contribution. This theory allowed a fair assessment of Tg values for unaged networks. During oxidation, epoxy networks were shown to undergo chain scissions occurring in great part in hydroxypropyl ether and isophorone groups. However, the exploitation of Tg changes showed the coexistence and even the predominance of crosslinking in materials having linear aliphatic segments. The DiMarzio's approach was used to discuss the possibility of intramolecular cyclization or intermolecular crosslinks which were shown to predominate. Crosslinks were tentatively justified from a mechanistic point of view and quantified depending on experimental conditions.

Face-to-face interviews with manufacturers of food cans and producers of canned foods in Thailand were performed to collect information in real practice regarding the use of coating resins with respect to packed food types. For export markets, epoxy-coated cans accounted for 58%, polyvinyl chloride organosol 35% and uncoated 7%. Meanwhile, the respective fractions for domestic markets were 83, 2 and 15%. The identification of coating polymers was confirmed using Fourier transmission infrared technique. It was found that acetonitrile extraction could be used to predetermine the compliance of coated cans before use, provided that the detected amounts are below the limits. Interestingly, the highest levels of bisphenol A diglycidyl ether (BADGE) and its hydrolysed products detected in simulants and 45 canned food samples were factors of 10 to 21 below its SML of 9 mg/kg, and the percentage of samples containing ‘non-detectable’ levels of BADGE ranging from 10 to 70; of chlorohydroxy BADGE – factors of 3 to 13 below 1 mg/kg, and the percentage of ‘non-detectable’ ranging from 57 to 85; and of bisphenol A – factors of 32 to 140 below 0.60 mg/kg, and the percentages of ‘non-detectable’ ranging from 0 to 95. The determination of BADGE and its derivatives was performed on a high-performance liquid chromatograph with a fluorescence detector, while bisphenol A using a gas chromatography–mass spectrometry technique. All cans and canned food samples extensively complied with European Union regulations and Japanese voluntary standards. Copyright © 2017 John Wiley & Sons, Ltd.

A sustainable novolac-type resin – phenol–hydroxymethylfurfural (PHMF) resin was prepared by reacting phenol with HMF, in-situ derived from glucose, at 120 °C by acid catalysis. Bisphenol A type epoxy resin, i.e. bisphenol A diglycidyl ether (DGEBA), was used as a formaldehyde-free curing agent by substituting conventional formaldehyde-based hexamethylene tetraamine (HMTA) to crosslink the PHMF resin. Curing mechanism was probed and the curing proceeded likely with the ring opening reaction between the DGEBA and reactive hydroxyl groups. DGEBA not only made this system truly formaldehyde-free but also helped form a void-free matrix which is an important merit for composites. The kinetic parameters of the curing reaction were evaluated with model-free and model-fitting methods using exothermal peak data from the curing process. The thermo-mechanical characterization of the cured resin and fiber reinforced bio-composites showed good heat resistance and mechanical performance, suggesting its potential for producing void- and formaldehyde-free composite materials.

Silica-epoxy nanocomposites were prepared via an “in-situ” sol-gel synthesis process and a phosphorus (P) flame-retardant i.e. 6H-dibenz[c,e][1,2]oxaphosphorin,6-[(1-oxido-2,6,7-trioxa-1-phosphabicyclo[2.2.2]oct-4-yl)methoxy]-, 6-oxide (DP) and melamine (Mel) were further added to the matrix to improve its fire performance. The main components of epoxy resin were bisphenol A diglycidyl ether (DGEBA) and isophorone diamine (IPDA) hardener. The addition of DP as well as silica alone into the epoxy system stopped the melt dripping phenomena in the vertical fire test (UL 94), however, the addition of melamine was crucial for achieving the highest fire classification (UL 94-V0 rating). The presence of DP and Mel in the silica-epoxy nanocomposite promoted a large reduction (ranging from 53% up to 80%) in the heat release rate (HRR) and a delay (up to 31%) in the ignition time in the cone calorimetry experiments. Improved fire performance of the epoxy system was attributed to i) a condensed phase activity of silica, DP and melamine to form a protective thermal barrier during combustion and ii) a minor gas phase flame inhibition activity of DOPO component of DP. The mechanical characterization of the epoxy nanocomposites through tensile tests showed that the addition of DP increases the stiffness of the epoxy resin, resulting in a strong increase of Young modulus (up to 32%) and in a slight decrease of fracture strength, elongation at break and toughness. An increased glass transition temperature (up to 8%) of the epoxy system possibly due to hydrogen bonds and polar interactions of DP with the matrix was also observed.

The effects of atomic oxygen on three commercial composite materials, based on two space-qualified epoxy resins (tetraglycidyl-4,4′-diaminodiphenylmethane (TGDDM) cured with a blend of 4,4′-methylenebis(2,6-diethylaniline) and 4,4′-methylenebis(2-isopropyl-6-methylaniline); and a blend of TGDDM, bisphenol A diglycidyl ether (DGEBA), and epoxidised novolak resin initiated by N’-(3,4-dichlorophenyl)-N,N-dimethylurea) are studied. Samples were exposed to a total fluence of (3.82 × 10 20 atom/cm 2 ), equating to a period of 43 days in low Earth orbit. The flexural rigidity and modulus of all laminates displayed a reduction of 5–10% after the first exposure (equivalent to 20 days in orbit). Fourier transform infrared (FTIR) spectra, obtained during prolonged exposure to atomic oxygen, were interpreted using multivariate analysis to explore the degradation mechanisms.

The present research focused on a coating formulation for aluminum surface 2024-T3 to protect it from corrosion. The formulation consisted of a polymeric epoxy resin-coated bisphenol A diglycidyl ether (DGEBA) cured with a polymeric polyaminoamide. The coated aluminum 2024-T3 was tested in a harsh environment of electrolyte solution (3 wt% NaCl solution) to simulate the harsh marine environment. The coated sample was evaluated by Electrochemical Impedance Spectroscopy (EIS). Under these conditions, a very high impedance (Z) value was obtained; even after exposure for a period longer than 4392 h, the performance was still acceptable. Surface morphological study of metallic specimens before and after exposures to the simulated marine environment (3 wt% NaCl) was carried out using scanning electron microscopy (SEM). The results indicate that the DGEBA-polyaminoamide (DGEBAAA) performed as an excellent barrier for Al surface. The results were combined by several modeling approaches involving molecular dynamics simulation (MD), Monte Carlo methods (MC), and the electronic density functional theory (DFT) computations to explore the adhesion forces between the DGEBAAA and the aluminum surface. The computational MD, MC, and DFT studies were executed in aqueous media. Computational results further evidenced the stronger DGEBA-aminoamide adhesion onto the aluminum 2024-T3 even in a wet environment.

Pb(II)-imprinted pectin-carboxymethyl chitosan-BADGE or Pb(II)-CPB was synthesized by mixed pectin (Pec) and carboxymethyl chitosan (CC) and then crosslinked with a crosslinking agent bisphenol A diglycidyl ether (BADGE) to form a stable adsorbent and resistant to acidic media. As a first step, the synthesis was performed by reacting the –OH group among Pec and CC with BADGE to form CPB. The Pb(II) ion was then imprinted with the Pec–CC gel and formed Pb(II)-CPB. Furthermore, the release of Pb(II) ions from the adsorbent was performed using the chelating agent, $$\hbox {Na}_{{2}}$$EDTA. The kinetic and thermodynamic equilibrium of the batch sorption of Pb(II) onto Pb(II)-CPB were investigated. The results of this study showed that the adsorption process of the Pb(II)-CPB adsorbent could be well described by the pseudo-second order model. The thermodynamic biosorbent in adsorption of the Pb(II) ion follows Freundlich isotherm. The adsorption energy of the adsorbent was 15.59 kJ $$\hbox {mol}^{-1}$$. This proves that the mechanism process of the adsorbent to Pb(II) ions occurs by physical adsorption. The Pb(II)-CPB adsorbent shows a significantly higher capacity compared to Pec and chitosan. Adsorption capacity of Pb(II)-CPB was $$664.44 \times 10^{-3}$$. The Pb(II)-CPB adsorbent has higher selectivity on $$\hbox {Pb}^{2+}$$ ions compared to Pec and CC with the adsorption selectivity order Pb(II)/Zn(II)$$ \, < \, $$Pb(II)/Cu(II).

In this study, combinations of bisphenol A diglycidyl ether (BPADGE) and polyethylenimine (PEI) were investigated as effective crosslinking agents for soy protein isolate (SPI) at room temperature. Three-ply plywood panels were prepared with the SPI-BPADGE-PEI adhesives via a cold press process and were evaluated for their water resistance and shear strengths in accordance with the requirements of the American National Standard for Hardwood and Decorative Plywood for exterior applications. The effects of BPADGE/(SPI + PEI) weight ratio, SPI/PEI weight ratio, solids content of the adhesive, the rate of adhesive usage, and the press time at room temperature on the water resistance and the shear strengths of plywood panels were investigated. The pot-life of the adhesive was also measured. Plywood panels bonded with the SPI-BPADGE-PEI adhesives met the industrial requirements for exterior applications.

Aromatic disulfide based vitrimers show elasticity driven shape-memory and plastic reprocessability via associative rearrangement of dynamic covalent crosslinks. Those processess represent the two sides of a coin: the storage and relaxation of the strain energy caused by a deformation load. The key temperatures that trigger the underlying mechanisms, i.e. phase transition and disulfide exchange reaction, are extremely sensitive to the molecular structure of the polymer and under certain condition overlap. To gain insight on the relationship between the structure, dynamic and shape-changing properties, five aromatic disulfide-based epoxy networks with a range of Tg values (32–142 °C), molecular structure and crosslink densities (2252–462 mol m−3) were synthesized. The epoxy matrices were formulated combining different ratios of rigid bisphenol A diglycidyl ether (DGEBA) and flexible poly(propylene glycol) diglycidic ether (DGEPPG) epoxy monomers crosslinked by 4-aminophenyldisulfide hardener.

This paper investigates the effects of increased reaction mixture viscosity on the kinetics of linear polymer creation in a bulk polyaddition process of diphenyl carbonate and bisphenol A diglycidyl ether. The paper presents a method for solving a system of bulk polyaddition of diphenyl carbonate and bisphenol A diglycidyl ether process balance equations, allowing the determinatiof the process kinetic parameters. Determination of polymerisation reaction kinetic parameters was also made possible by the use of the so-called partial reaction rate constant. Such an approach enabled a significant simplification of the mathematical expressions describing the heteropolyaddition process and provided an opportunity to associate kinetic parameters with the average molar mass of the mixture and, thus, with the viscosity. The method presented herein facilitates an analysis of the linear polymers heteropolyaddition process.

The flame retardancy, thermal, and mechanical properties of the cured epoxy resins are difficult to be simultaneously improved. In the present work, a novel DPPA-based curing agent, 10-[(4-hydroxyphenyl)(4-hydroxyphenylimino)methyl]-5,10-dihydrophenophosphazine 10-oxide (H-DPPA), is successfully synthesized to serve as a co-curing agent of 4, 4′-diaminodiphenylmethane (DDM) for bisphenol A diglycidyl ether (DGEBA) epoxy resin. With the aid of 3.0 wt % of H-DPPA, the cured epoxy resin, in which the phosphorus content is as low as 0.22%, passes V-0 rating of UL-94 test with limiting oxygen index (LOI) of 31.8%. The high flame retardancy of epoxy resin modified by H-DPPA originated mainly from the formation of intumescent char layer during combustion. This new type of flame retardant containing both phosphine oxide structure and nitrogen moieties provides epoxy resins with excellent integrated performances.

In this work, a coarse-grained model is developed for highly cross-linked bisphenol A diglycidyl ether epoxy resin with diaminobutane hardener. In this model, all conformationally relevant coarse-grained degrees of freedom are accounted for by sampling over the free-energy surfaces of the atomic structures using quantum mechanical simulations. The interaction potentials between nonbonded coarse-grained particles are optimized to accurately predict the experimentally measured density and glass-transition temperature of the system. In addition, a new curing algorithm is also developed to model the creation of highly cross-linked epoxy networks. In this algorithm, to create a highly cross-linked network, the reactants are redistributed from regions with an excessive number of reactive molecules to regions with a lower number of reactants to increase the chances of cross-linking. This new algorithm also dynamically controls the rate of cross-linking at each local region to ensure uniformity of the resulting network. The curing simulation conducted using this algorithm is able to develop polymeric networks having a higher average degree of cross-linking, which is more uniform throughout the simulation cell as compared to that in the networks cured using other curing algorithms. The predicted gel point from the current curing algorithm is in the acceptable theoretical and experimental range of measured values. Also, the resulting cross-linked microstructure shows a volume shrinkage of 5%, which is close to the experimentally measured volume shrinkage of the cured epoxy. Finally, the thermal expansion coefficients of materials in the glassy and rubbery states show good agreement with the experimental values.