Mechanical Properties Of Resin Research Articles

Novel kraft-lignin-based adhesives for the production of particleboards

Lignin is produced worldwide in pulp mills and is currently mainly used for energy recovery. Because of its chemical properties, one possible utilisation is the production of lignin-based materials. Currently, developed lignin-based adhesives are based mainly on lignosulfonate instead of kraft lignin since lignosulfonate is more reactive than kraft lignin. However, worldwide substantially more kraft lignin is produced. The presented research deals with the development of resin chemically modified with kraft lignin up to 40% (w/w) content of kraft lignin. The synthesis of adhesives is described, and developed adhesives are characterised. Namely, viscosity, mechanical properties of resins and results of differential scanning calorimetry are presented. Furthermore, the developed kraft-lignin-based adhesives were used for the production of particleboards. Pre-pressing in a cold press followed by hot pressing in a laboratory press was used for the production of particleboards. The physical (thickness swelling, moisture uptake, vertical density profile), as well as mechanical (internal bonding, modulus of rupture, modulus of elasticity in three-point bending) properties of particleboards, were evaluated. The results clearly show that kraft lignin can be used for the production of lignin-based adhesives for the production of particleboards.

Epoxy resin mechanical properties in composition with copper (I) oxide particles, encapsulated by polylactide with variable thickness

The required functional and mechanical properties are necessary for design the polymer compositions with dispersed fillers. The mechanical properties of such polymer composition can be changed by encapsulated filler particles shell thickness varying. The paper shows that the presence of polylactide polymer shell and its thickness on the surfaces of copper (I) oxide particles significantly affect the strength of polymer composite material based on ED-20 epoxy resin. That is due to the interaction between encapsulated particles and the matrix polymer, in contrast to noncapsulated particles. In addition, a change in particle size due to increasing shell thickness also affects the strength properties of the composition. It is shown that the elastic modulus of the filled epoxy composite does not depend on the shell thickness on the particle surfaces.

Restorative Dental Resin Functionalized with Calcium Methacrylate with a Hydroxyapatite Remineralization Capacity.

The ability of dental materials to induce the mineralization of enamel like hydroxyapatite (HA) is of great importance. In this article, a novel kind of dental restorative material characterized by a mineralization ability was fabricated by photopolymerization. Calcium methacrylate (CMA) was introduced into the classical bisphenol A-glycidyl methacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) dental resin formulation. This functional dental resin (BTCM) was calcium-rich and can be prepared simply by one-step photopolymerization. The influence of CMA on the photopolymerization kinetics, the dental resin's mechanical properties, and its capacity to induce dynamic in situ HA mineralization were examined. Real-time FTIR, compression modulus, scanning electron microscopy, X-ray spectroscopy, MTT assay, and cell attachment test were carried out. The obtained data were analyzed for statistical significance using analysis of variance (ANOVA). Double bond conversion could be completed in less than 300 s, while the compression modulus of BTCM decreased with the increase in CMA content (30 wt%, 40 wt%, and 50 wt%). After being soaked in Ca(NO3)2 and Na2HPO4 solutions alternatively, dense HA crystals were found on the surface of the dental resin which contained CMA. The amount of HA increased with the increase in CMA content. The MTT results indicated that BTCM possesses good biocompatibility, while the cell adhesion and proliferation investigation demonstrated that L929 cells can adhere and proliferate well on the surface of BTM. Thus, our approach provides a straightforward, cost-effective, and environmentally friendly solution that has the potential for immediate clinical use.

Performance optimization of epoxy resin(EP) modified by phenolic and effect on the tribological properties and corrosion ofMoS2 + Sb2O3/EPcomposite coating for ultra‐long wear life and good corrosion resistance

AbstractResin as a continuous and base phase plays a key role in the organic bonded solid lubricating (OBSL) coating. However, the influence mechanism of resin mechanical properties on tribological properties and corrosion resistance of coatings remains elusive. Here, the effect of crosslink density of epoxy resin modified by phenolic resin (Abbr. EP/PH) on the tribological performance /corrosion protection of MoS2 + Sb2O3/EP composite coating has been elucidated. The tribology and corrosion properties of the coatings with different crosslink densities were analyzed by SEM/EDS, XRD, XPS, and EIS. The result indicates that when the crosslink density of resin in the coating is moderate of 460 mol/m3and the elastic modulus reaches the highest value of 2217 MPa, the MoS2 + Sb2O3/EP composite coating shows low friction coefficient about 0.01, long anti‐wear life (≥480 min), and good corrosion resistance with the higher value of |Z|0.01Hz(1.92 × 1010 Ω cm2) after 72 h of immersion than other coatings. In addition, the too high or too low crosslink density of EP/PH resin is not beneficial to improve the performance of coating. It is because the mechanical strength and toughness of resin with appropriate crosslink density are enhanced greatly, which ensures a tight bond between the filler as a dispersed phase and resin as a continuous phase to form the compact micro‐structure of coating, which improve the strength and shielding capacity of coating, so the MoS2 + Sb2O3/EP composite coating shows good tribological properties and anti‐corrosion.HighlightsThe effect of resin crosslink density on property of coating has been studied.The strength of resin with suitable crosslink density are enhanced greatly.The coating shows good tribological properties and shielding capacity.The crosslink structure of resin has a great influence on coating properties.

The effect of chicken eggshell (Gallus gallus domesticus) particle size as filler to polyester composite as motorcycle’s exhaust pipe cover material

This research was done to know the effect of chicken eggshell (Gallus gallus domesticus) powder particle size on unsaturated polyester resin mechanical properties. The eggshell was mashed and sifted to get the 50 mesh, 70 mesh, 90 mesh, 110 mesh, 130 mesh, 150 mesh, and 170 mesh particle size by using a ball mill. Then, the eggshell was mixed with an unsaturated polyester resin matrix with the ratio of 70:30 and methyl ethyl ketone peroxide (MEKP) catalyst as much as 1 % of the matrix mass. After that, it was pressed by using compression molding. The composite formed was characterized by Scanning Electron Microscopy Energy Dispersive X-ray (SEM EDX), Fourier Transform Infra-Red (FTIR), and X-Ray Diffraction (XRD). The physical properties of the composite were analyzed and the mechanical properties were tested. The SEM EDX result showed that the eggshell and composite were made up of Ca, C, and O, and the polyester was made up of C, O, and Si. The composite highest tensile strength and impact strength were at 150 mesh particle size of chicken eggshell powder which is 45.153 MPa and 9. 04 J/m2.

Improving water resistance and mechanical properties of waterborne acrylic resin modified by 3,3′,5,5′-tetramethyl-4,4′-biphenyl diglycidyl ether

3,3′,5,5′-tetramethyl-4,4′-biphenyl diglycidyl ether (TMBPDGE) modified waterborne acrylic resin with excellent water resistance and mechanical properties was synthesized by a homogeneous solution polymerization. Infrared analysis revealed that TMBPDGE could successfully participate in the synthesis. On this basis, the experimental conditions such as polymerization method, solid content, monomer addition method and curing temperature are optimized by using the results of immersion test, contact angle, tensile strength, elongation at break and hardness determination. The optimal amount of TMBPDGE is investigated and the resin is further characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The experimental results show that when the amount of TMBPDGE is 10 wt%, the water resistance and mechanical properties of the resin are greatly enhanced, and the cured resin film modified by TMBPDGE can withstand the soaking in water for more than 35 days, while that of film without modification is only one day. The tensile strength can reach 9.12 MPa, which is 2.2 times than that of the film without modification. Based on the enhanced properties, the modified resin provides a great potential in the fields of wood coatings, which require good water resistance and mechanical properties.

Impact of winding on nanoimprinted surfaces in roll‐to‐roll nanoimprint lithography

AbstractRoll‐to‐Roll manufacturing aims at scaling ultraviolet‐ and thermally cured nanoimprint lithography (UV‐NIL, T‐NIL) to commercial production speeds and volumes. Winding is the only convenient way of storing large quantities of nanoimprinted webs as they await unwinding in sequential R2R processes with distinct transport speeds. At production speeds, the imprinted resin is still chemically evolving when the imprinted web enters the winder, through a phenomenon called dark curing. The viscoelastic resin at various curing stages deforms under the contact pressure due to winding. This study is concerned with the impact of the contact pressure on the imprinted peak heights and potentially the functionality of the nanoimprinted surface. We develop a multiscale numerical model of the winding of the imprinted web. First the evolving properties of the resin through time are characterized, combining the effect of dark curing and viscoelasticity on the time‐dependent properties. Second, a finite element model of the imprinted web uses the resin mechanical properties to determine the effective properties of the imprinted web. Finally, the winding model determines the pressure and resulting strain of the imprints in the wound roll. The surface creep is quantified. This prediction will establish how and how long the imprinted materials should be wound.

Effect of thermo-oxidative ageing on the thermo-mechanical responses of 3D braided carbon fiber/epoxy composites during high-speed impact

By developing a thermo-mechanical coupled model, we quantitatively analyzed the effect of thermo-oxidative ageing on the temperature, thermal strain and thermal stress histories of braided composites during high-speed impact. We also considered temperature dependence of elastic modulus during impact in this model. The proposed model was first applied to the unaged composites, then the results were compared to the impact responses captured by the split Hopkinson bar and the high-speed camera. The comparisons of the experimental and numerical results show that the proposed model could capture the adiabatic temperature rise, stress-strain responses and failure process of braided composites during high-speed impact. The validated model was subsequently employed to thermo-oxidative aged composites. Results show that the temperature rise, thermal strain and thermal stress all depend on the mechanical properties of resin, and they decreased with the increase of ageing temperature since the performance of resin is compromised by thermo-oxidation ageing. The change of resin performance after ageing leads to the change in the temperature rise during impact, so the stiffness of composites will decrease in varying degrees after ageing.

Exploring New Resin Systems for Nb3Sn Accelerator Magnets

Epoxy resins have long been a focus of magnet design. They provide strength and stability to the superconductor, to allow coil fabrication and consistent magnet performance. They are often cited as a main contributor to magnet performance, often as a limiting factor, from epoxy cracking and energy release. New resin systems are being designed to improve magnet quench and training performance through several means. Baseline candidate resin systems are evaluated for neat resin mechanical properties as well as behavior in Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn subscale composites. This data feeds additional resin system tuning to meet the goals stated above.

Comparison of CAD/CAM and Conventional Denture Base Resins: A Systematic Review

At present, complete dentures (CDs) remain the only treatment available for the majority of edentulous patients. CDs are primarily fabricated using a conventional method using polymethylmethacrylate (PMMA) resin. The steps involved in PMMA polymerisation directly affect the quality of the resin prosthetic base and any error reduces retention and occlusal accuracy of CDs. Furthermore, when using the conventional technique, the residual monomer alters the resin mechanical properties and may cause mucosal reactions. Recently, computer aided design and computer aided manufacture (CAD/CAM) techniques were increasingly used to fabricate CDs by machining resin discs that have been manufactured under high pressure and temperature. This systematic review compares CAD/CAM and conventional CDs according to their mechanical, physical and chemical characteristics, as well as the clinical impact of any differences between them. A review was conducted according to the preferred reporting items for systematic reviews and meta-analyses checklist on 392 publications from both PubMed and backward research. Fifteen studies have been included. Results showed that CAD/CAM resins had globally better physical and mechanical properties than conventional resins. The use of machined resin could improve the clinical performance, maintenance and longevity of CDs. Further studies in clinical use would be required to complement these results.

Bis(4-methyl phenyl)iodonium as an alternative component to diphenyliodonium in camphorquinone-based ternary initiating systems

ObjectiveTo evaluate the influence of different co-initiators (diphenyliodonium hexafluorophosphate - DPI - and bis(4-methyl phenyl)iodonium hexafluorophosphate – BPI) on chemical and mechanical properties of resins. MethodsNine experimental resins (50% Bis-GMA and 50% TEGDMA, w/w) with 60 wt% filler particles were formulated. The initiating system used was camphorquinone (CQ-1 mol%) and ethyl dimethylaminobenzoate (EDAB-2 mol%). Experimental groups were established according to DPI and BPI quantities (0.25, 0.5, 0.75, and 1 mol%). The control group was a resin containing only CQ-EDAB. Light transmission through the resin during polymerisation was analysed with a UV–vis spectrophotometer. Real-time polymerisation of the systems was evaluated using an FTIR spectrometer. Real-time polymerisation shrinkage strain was evaluated, and the flexural strength and modulus of materials were obtained by 3-point bending. Experimental groups were statistically analysed by Analysis of Variance and Tukey’s test (α = 0.05). Dunnett’s test was applied to compare experimental groups with control. ResultsLight transmission rapidly increased initially for resins containing DPI or BPI. After 30 s cure, the irradiance on the lower surface of resin specimens was similar for all groups. After 10 s of light irradiation, groups containing DPI and BPI had higher conversion than the control. However, conversion after 120 s post-irradiation was similar for all groups. The rate of polymerisation, shrinkage strain, and the maximum strain rate were higher for groups containing DPI/BPI. The use of iodonium salts increased the flexural strength and flexural moduli of resins. SignificanceDPI and BPI increased resin reactivity similarly. Increased rate of polymerization influenced light transmission through the resin in the first seconds of polymerisation and increased resin shrinkage and rate of shrinkage, as well as flexural strength and moduli.

Analytical predictive model for the long-term bond performance of CFRP tendons in concrete

The bond between Carbon Fiber Reinforced Polymer (CFRP) tendons and concrete depends on the resin mechanical properties that can degrade under environmental conditions. An analytical model to predict the combined effects of temperature and humidity fluctuations on the bond behaviour of CFRP tendons embedded in concrete is presented. The interaction between a CFRP tendon and concrete is studied by considering different competing mechanisms such as tendon swelling and plasticisation effects due to the concrete internal humidity, differential thermal expansion, concrete autogeneous shrinkage, Poisson’s ratio effects and radial bond stresses generated during the pulling out of a tendon from concrete. The analytical bond failure predictions correlate reasonably well with experimentally observed radial-cracking failure modes of CFRP tendons in high strength concrete. Matrix plasticisation appears to influence the long-term bond strength of FRP rods in normal or high strength concrete. Swelling and shrinkage effects become significant in uncoated tendons due to their impact on the frictional bond component. Deviations between measured and predicted bond strength values are attributed to a possible overestimate of the moisture-induced swelling expansion of CFRP tendons. The research findings suggest the introduction of environmental bond factors to consider durability effects in the design of FRP prestressed concrete structures.

Prediction of mechanical properties on 3D braided composites with void defects

Void defects have appeared inevitably during the manufacturing process of braided composites, which directly affect the mechanical properties and strength of braided composites. First, the influence of internal void and porosity on the mechanical properties of resin was predicted. Second, the evolution in the mechanical properties of three dimensional (3D) braided composites was obtained using the Mori-Tanaka method. Finally, the strength prediction, failure mode, stress and strain field of 3D braided composites with void defects were investigated by means of finite element simulation based on the progressive damage theory in ABAQUS, which will compare the simulation results with the theoretical results and other scholar's experiments. The innovation of this work is to establish the constitutive model and finite element model of 3D braided composite material with voids and predict the evolution of the mechanical properties of 3D braided composite material with defects. The results will provide the theoretical and design basis for evaluating the influence of void defects on the mechanical properties of 3D braided composites.

Effect of residual solvent on performance of acrylamide-containing dental materials

ObjectiveMethacrylamide-based monomers are being pursued as novel, hydrolytically stable materials for use in dental adhesives. The impact of residual solvents, due to the chemical synthesis procedures or the need for solvated adhesives systems, on the kinetics of polymerization and mechanical properties was the aim of the present investigation. MethodsTwo base monomers (70wt% BisGMA or HEMAM-BDI — newly synthesized secondary methacrylamide) were combined with 30wt% N,N-dimethylacrylamide. Eethyl acetate (EtOAc), or 75vol% ethanol/25vol% water (EtOH/H2O) were added as solvents in concentrations of 2, 5, 15 and 20wt%. The resins were made polymerizable by the addition of 0.2wt% 2,2-dimethoxy-2-phenyl acetophenone (DMPA) and 0.4wt% diphenyliodonium hexafluorophosphate (DPI-PF6). Specimens (n=3) were photoactivated with a mercury arc lamp (Acticure 4000, 320–500nm, 250mW/cm2) for 5min. Degree of conversion (DC, %) was tracked in near-IR spectroscopy in real time and yield strength and modulus of elasticity were measured in three-point bending after dry and wet storage (n=6). The data was subject to one-way ANOVA/Tukey’s Test (p≤0.05), or Student’s t-test (p≤0.001). ResultsIn all groups for both BisGMA and HEMAM-BDI-based materials, DC and DC at Rpmax increased and maximum rate of polymerization decreased as solvent concentration increased. Despite the increased DC, BisGMA mixtures showed a decrease in FS starting at 5wt% EtOAc or 15wt% EtOH/H2O. Yield strength for the HEMAM-BDI groups was overall lower than that of the BisGMA groups, but the modulus of elasticity was significantly higher. SignificanceThe presence of residual solvent, from manufacturing or from practitioner’s handling, affects polymerization kinetics and mechanical properties of resins. Methacrylates appear to be more strongly influenced than methacrylamides.

Influence of Commercial Biochar Fillers on Brittleness/Ductility of Epoxy Resin Composites

Production of versatile composites is a very attractive field. Carbon containing epoxy resins are one of the most relevant reinforced plastics used for a wide number of applications. In this research, we studied the influence of five different commercial biochar samples for the selective enhancement of brittleness and ductility of an epoxy based composite. We proved the relationship between biochar morphology and composites mechanical properties with the aid of FT-IR and FE-SEM analysis. We were able to improve the neat resin mechanical properties by doubling its Young’s modulus and ultimate tensile strength using a wheat straw derived material, and to increase its elongation by 40%, we used a Miscanthus derived biochar.

Effect of the cutting speed on the cutting mechanism in machining CFRP

Cutting mechanism of CFRP is different from that of a homogeneous metal. For metal, high speed cutting can improve machining quality and efficiency. However, there is no agreed conclusion on the effect of cutting speed on the cutting mechanism of CFRP. This paper studies the effect of cutting speed on cutting mechanism of CFRP and damage formation by using finite element and experiment methods. A three-dimensional finite element model of orthogonal cutting CFRP is established considering the strain-rate-dependent mechanical properties of resin and the anisotropy of fiber. By this model, cutting processes at micro level are simulated. Fracture evolution processes of fiber and resin are characterized. Furthermore, experimental data of cutting forces are obtained, and the machined surface microstructure are observed based on orthogonal cutting experiments. Subsurface morphology and degree of resin cracking extension in simulation and experiment are consistent with each other. Results show that with the increase of cutting speed, the fiber deformation and the affected area before fiber fracture obviously deceases. Accordingly, the resin cracking and extension degree caused by the excessive deformation of fiber also be greatly reduced. In addition, there is a trend that the specific energy gap for different chip formation modes becomes smaller and smaller.

Ocena porównawcza właściwości mechanicznych cementów żywicznych, samoadhezyjnych i samotrawiących

Ocena porównawcza właściwości mechanicznych cementów żywicznych, samoadhezyjnych i samotrawiących

Evaluation of Epoxy Resin Thermal Degradation and its Effect on Preventing Sustained Casing Pressure in Oil and Gas Wells

Epoxy resin applications in oil and gas wells have significantly increased for remediation and sustained casing pressure mitigation because of its solids-free nature and excellent thermomechanical/bonding properties when used either as a single component or as a resin/cement-enhanced composite. Therefore, it is imperative to assess the formation and degradation of structures in cured epoxy resin at downhole temperatures, particularly because hydrocarbon production requires long-term wellbore integrity. Differential scanning calorimetry was used to determine the glass transition temperature ( $$T_{\mathrm{g}}$$ ) of the proposed resin system, and thermogravimetric analysis (TGA) was used to characterize the thermal degradation response by monitoring the resin specimens’ mass loss over time under controlled temperature ranging from 300 to $$680\,{^{\circ }}\hbox {F}$$ at atmospheric pressure. The thermal kinetic response based on TGA was then modeled using the Arrhenius equation to predict the resin lifetime under expected wellbore conditions. This work also presents a case study in which an epoxy resin–cement composite is used as an annular barricade to help prevent and reduce sustained casing pressure. The resin–cement composite was placed in the annular section between the 18 5/8- and 13 3/8-in. casing sections as a chemical packer tailored to improve bonding to steel pipe, along with optimizing its mechanical response to cyclic downhole loads, which resulted in no up-to-date sustained casing pressure. For a resin system subjected to downhole temperatures of $$263\,{^{\circ }}\hbox {F}$$ , the model predicts that reaching 10% mass loss by thermal degradation can take more than 160 years, which is beyond the operational life of the wells where the system is evaluated. This indicates that the investigated resin system provides long-term dependability that ultimately results in reduction of intervention/remediation costs, along with production maximization. Additionally, the resin mechanical properties were evaluated at different temperatures to assess their response to expected thermal loading, which resulted in competent barriers that can withstand the cyclic loads generated by continuous wellbore operations. Furthermore, cement bond log results further support the optimum annular integrity attained when utilizing a cement–resin composite as chemical packer for enhanced isolation and annular pressure buildup mitigation.

Synergistic effects of thermoplastic and nanoclay on the performance properties and morphology of epoxy resin

The present work investigates the properties and morphology of nanobent/poly(methyl methacrylate) (PMMA)/epoxy resin hybrid nanocomposites which were successfully prepared by solvent and ultrasonication methods. Nanobent ZS1 were added in amount of 1, 2, 3, and 4 wt% and 5, 10, and 15 wt% for PMMA. The fracture toughness (impact strength and critical stress intensity factor) and flexural properties were evaluated for epoxy composites. Obtained results showed improvement of the epoxy resin mechanical properties due to the addition of PMMA and nanobent. Composites containing 5 wt% of polymeric modifier or 1 wt% nanobent exhibited maximally improved properties. In the case of hybrid composites, synergistic effect was obtained with flexural strain at break and flexural energy to break of hybrid nanocomposite based on 1 wt% nanobent and 5 wt% PMMA. However, epoxy nanocomposites based on 2 wt% nanobent and 5 wt% PMMA showed synergism with IS and brittle fracture energy toward the composites with one modifier. Fourier transform infrared (FTIR) spectra analysis confirmed interactions between incorporated modifiers and reactive groups of the epoxy matrix. Moreover, scanning electron microscope (SEM) micrographs of hybrid epoxy nanocomposites exhibited a morphology with large plastic yielding associated with significant roughness of the fracture surface with embedment of nanobent in the polymer system. This study clearly demonstrates that the improvement of mechanical properties of the epoxy resin could be attributed to the synergistic toughening effect of PMMA and nanobent without deterioration of thermal stability. POLYM. COMPOS., 39:E2540–E2551, 2018. © 2018 Society of Plastics Engineers

Effect of change in mechanical properties of resin on strength characteristic in resin/ metal dissimilar materials joint

Effect of change in mechanical properties of resin on strength characteristic in resin/ metal dissimilar materials joint