Resin Particle Size Research Articles

Dispersion and stability of SiC ceramic slurry for stereolithography

Stereolithography based additive manufacturing provides an effective method to fabricate complex-shaped SiC ceramic components. The dispersion and stability of the ceramic slurry are very important for stereolithography. In this study, the dispersion and stability of SiC ceramic slurries were investigated systematically. The effects of resin monomers, dispersants, particle size, solid loading and ball milling time on the dispersion, rheological behavior and stability of SiC ceramic slurries were studied in detail. Finally, an optimal SiC ceramic slurry for stereolithography based additive manufacturing was obtained, and complex-shaped SiC ceramic architectures were fabricated.

Compatibility of cured phase-inversion waterborne epoxy resin emulsified asphalt

Since the waterborne epoxy resin emulsified asphalt (WEREA) showed many advantages over the epoxy asphalt binder (EAB), it had been studied recently, but the compatibility of cured WEREA had not been paid attention to, which was studied by this paper. Through the analysis of solubility parameter difference, the storage stability and the Fourier transform infrared spectrum (FT-IR), WEREA was firstly turned out to be chemically incompatible. After that, based on fluorescent morphologies of WEREA, by the analysis of parameters of the gray-level co-occurrence matrix, it was found that smaller particle size of the waterborne epoxy resin (WER) in WEREA contributed to better technical compatibility of WEREA. Accordingly, the optimized phase-inversion condition of WER was proposed. Then, from fluorescent morphologies of cured WEREA and scanning electric microscopic (SEM) morphologies of the left skeleton of cured WEREA after the “dissolving-evaporating” process, the “sea island” structure and the “IPN-liked” structure were observed, respectively, and the transformation of the “sea island” structure to the “IPN-liked” structure was also observed when the content of WER in WEREA increased from 20% to 30%. Meanwhile, through the analysis of the angular second moment, the entropy and the entropy-energy ratio of gray-level images of fluorescent morphologies of cured WEREA, it was found that the technical compatibility of cured WEREA becomes better with the increase of WER content in WEREA when the WER content is less than 30%. Finally, through tests of interlayer properties of cured WEREA and pavement performance of WEREA mixture with different WER contents, it was turned out that better compatibility of cured WEREA contributed to better interlayer properties of cured WEREA and the molded strength and high temperature stability of WEREA mixture, and the content of WER where the “IPN-liked” structure forms was verified as between 20% and 25%.

Separation of monoclonal antibody charge variants using cation exchange chromatography: Resins and separation conditions optimization

The separation of charge variants is a challenge for the production of monoclonal antibodies (mAbs). Cation exchange chromatography (CEX) is normally used to accomplish this task. In this study, with IgG1-type mAb as the model protein, charge variants separation was investigated under various conditions including resins, elution mode, gradient slope and flow rate. The trade-off between main peak purity and recovery was focused to evaluate the separation performance. The results indicated that the diameter of resin particles was the critical factor. For SP Sepharose Fast Flow (90 μm diameter resin), the overlap between main peak and charge variants was too serious to meet the separation requirements. For Monomix MC30 SP (30 μm diameter resin), the purity of main peak was improved to 93.4% under 0.05 pH/CV and 100 cm/h. For Nano SP-15L (15 μm diameter resin), near 100% purity of main peak could be obtained with a recovery of 56.5% under 0.05 pH/CV and 100 cm/h. Two types of elution gradient, salt gradient and pH gradient, were compared and it was found that there was no obvious difference after the optimization and both showed some improvements with a shallower gradient. In addition, slower flow rate could improve the separation of main peak. In general, smaller resin particle size, shallower gradient slope and slower flow rate could improve the separation performance of main peak and charge variants under both salt gradient and pH gradient elution, which should be selected according to the actual requirements.

Effects of the resin content and particle size on the properties of particleboard made of Neolamarckia and Leucaena particles

A shortage in the rubberwood supply is becoming a reality in Malaysia. To find alternative raw materials for Malaysian wood-based industries, fast-growing species have been identified and need to be analyzed in particleboard manufacturing. This study evaluated the properties of particleboard made with a 50:50 ratio of Neolamarckia cadamba and Leucaena leucocephala with melamine urea formaldehyde as the resin at different contents (10%, 12%, and 14%) and particle sizes (1.0 mm, 2.0 mm, and unscreened particles). The particleboards were tested according to EN 312 (2003). The results showed that the particleboard mechanical properties were significantly improved with increase of the resin content and particle size. The thickness swelling value dropped as resin content was increased, showing better stability of the board.

La eliminación de metales tóxicos presentes en efluentes líquidos mediante resinas de cambio iónico. Parte IX: Plomo(II))/H+/Amberlite IR-120

El plomo está considerado como un metal altamente peligroso para los seres humano, por lo que su eliminación, de cualquier medio que lo contenga, suele ser de la máxima importancia. Comúnmente y a valores de pH inferiores a 5-6, este elemento esta presente en los medios acuosos como catión Pb2+. En el presente trabajo se investiga la eliminación de este catión de disoluciones acuosas empleando la tecnología de cambio iónico con la resina Amberlite IR-120. Se consideran una serie de variables que pueden afectar al proceso de carga del metal en la resina: velocidad de agitación del sistema, temperatura, dosificación de la resina y tamaño de partícula de la misma y pH del medio acuoso. La carga del metal responde a la isoterma de Freundlich, siendo el proceso endotérmico y no espontáneo, el mecanismo de carga no depende del tamaño de partícula de la resina y responde a un mecanismo por difusión en el medio acuoso. La eliminación del plomo(II) de disoluciones acuosas mediante la resina compite de forma favorable con respecto a los resultados obtenidos cuando se emplean nanotubos de carbono de pared múltiple como adsorbentes del Pb2+. En ensayos llevado a cabo con disoluciones binarias, la carga del Pb2+ en la resina también compite favorablemente con respecto a la de otros metales base en forma catiónica. La elución del plomo(II) se puede llevar a cabo de forma casi cuantitativa con disoluciones de HCl y distintas condiciones experimentales.

Influence of Resin Content and Particle Size on Particleboard from Leucaena Leucocephala

Influence of Resin Content and Particle Size on Particleboard from Leucaena Leucocephala

Recycled wind turbine blades as a feedstock for second generation composites

With an increase in renewable wind energy via turbines, an underlying problem of the turbine blade disposal is looming in many areas of the world. These wind turbine blades are predominately a mixture of glass fiber composites (GFCs) and wood and currently have not found an economically viable recycling pathway. This work investigates a series of second generation composites fabricated using recycled wind turbine material and a polyurethane adhesive. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resinated and compressed to a final thickness. The refined particle size, moisture content and resin content were assessed for their influence on the properties of recycled composites. Static bending, internal bond and water sorption properties were obtained for all composites panels. Overall improvement of mechanical properties correlated with increase in resin content, moisture content, and particle size. The current investigation demonstrates that it is feasible and promising to recycle the wind turbine blade to fabricate value-added high-performance composite.

Effect of separation material particle size on pressure drop and process efficiency in continuous chromatographic separation of glucose and fructose

Abstract Effect of the particle size (250–320 µm) of gel type strong cation exchange resins in Ca2+ form on the pressure drop across the resin bed and on the efficiency of chromatographic glucose–fructose separation was investigated experimentally. Pressure drop caused by the resin bed was found to depend strongly on the particle size. Strong dependency of the pressure drop on the solution viscosity was also observed. No elastic deformation of the resin particles was observed as in each case the dependence of the pressure drop on flow rate was linear. Both material (water consumption) and energy aspects were addressed in the investigation of the effect of particle size on the efficiency of continuous glucose–fructose separation. An eight-column four-zone simulated moving bed (SMB) process was used. The water consumption was found to decrease by 53% by change of particle size from 320 µm to 250 µm. This could be achieved without compromising specific productivities or product yields and purities by proper adjustment of the operating parameters. Lower water consumption results in more concentrated product fractions which decreases the energy consumption of the product concentration step (evaporation). Change in resin particle size from 320 µm to 250 µm decreased the energy consumption in evaporation by 18%, but resulted in 50% increase in the energy consumption of the pumps due to higher pressure drop. However, the total (pumps and evaporation) energy consumption decreased as the product concentration step is significantly more energy intensive unit operation.

Thermally Conductive General-Purpose Polystyrene (GPPS)/Graphite Composite with a Segregated Structure: Effect of Size of Resin and Graphite Flakes

ABSTRACTGeneral-purpose polystyrene (GPPS)/graphite flake composites with a segregated structure were fabricated by newly developed binder mixing method, aiming at highly thermally conductive polymer composites. The coefficient of thermal conductivity of the GPPS/graphite composites can be easily improved to be 3.5 W m−1 k−1 at a graphite flakes loading of 24.7 vol%, showing an improvement of more than 2,000% compared with pure GPPS. The thermal conductivity of the composites increased with the increasing particle size of graphite flakes, while the mechanical properties of composites are decreased with the increasing particle size of GPPS resin particles.

Fundamental Investigation of E-Coat Systems for Next Generation Corrosion Control

Electrodeposition of coatings is widely used in the auto industry to protect against corrosion. Increased fundamental understanding is needed to enhance the effectiveness of coatings while decreasing the environmental risks associated with surface treatments and coatings, as well as the processes used to form them. In addition, the incorporation of fundamental understanding into modeling tools will help to improve the quality of predictions and ensure that the desired level of corrosion protection is achieved. Fundamentally based models can also provide insight to guide the development and use of new types of environmentally friendly surface pretreatments. Key parameters of interest to the present study include the coulombic efficiency (mass deposited per charge), the coating resistivity, bath conductivity, the degree of neutralization and the extent of amine substitution. The influence of operating conditions such as temperature and flow on these parameters is also critical. In this study, experiments are performed to investigate the influence of factors such as the degree of neutralization and the extent of amine substitution on the size of resin particles in solution and on the processes that render the resin insoluble, leading to deposition. Models are used to describe and quantify critical mechanisms. The impact of key parameters on the local deposition rate and on the coulombic efficiency is demonstrated. The ability to determine the local deposition rate is critical to the performance of large-scale systems and to our ability to predict that performance for a variety of bath compositions, operating conditions, and surface pretreatments.

Thin particleboard quality: effect of particle size on the properties of the panel

Particle size and press time are always two effective factors in the manufacturing of particleboard. In this work we have investigated the effect of these factors on thin particleboard. Experimental 3 mm panels were made while particle size, press time and type of resin have been changed in 4, 3 and 3 levels respectively. Modulus of rupture, internal bond strength, modulus of elasticity, water absorption (2 and 24 h) and thickness swelling (2 and 24 h) of the panels made with a target density of 0.65 g/cm3 were investigated. Based on the results of this work, the particleboards made from phenol formaldehyde resin with mixed size particles in 180 s press time, showed the maximum flexural strength (18/46 MPa). The highest MOE (2027/55 MPa) was found for particleboards that made from melamine formaldehyde resin with particle in size −12 + 18 mesh and 120 s press time. Internal bonding of the panels made with melamine formaldehyde resin, particle size −12 + 18 mesh and 180 s press time exhibited the best results (1/75 MPa). Besides, the best panels in term of thickness swelling were made from phenol formaldehyde with particle size −8 + 12 mesh and 180 s press time. The lowest amount of water absorption for panels manufactured from phenol formaldehyde resin with mixed particles and −18 + 20 mesh and 180 s press time happened.

Synthesis of reusable macroporous St/BMA copolymer resin and its absorbency to organic solvent and oil

In this paper, a reusable macroporous high oil absorption resin for oil spills was synthesized successfully by suspension copolymerization with styrene and butyl methacrylate as monomers. In the process of suspension copolymerization, a porogenic agent was introduced into the reaction system. Structure and surface morphology of the macroporous resin were characterized by Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, and scanning electron microscopy. In addition, effects of different reaction factors on density and particle size of macroporous resins and effects of various factors on the oil absorbency of macroporous resins were discussed. Furthermore, oil absorption kinetics and repeatability of resin and the absorbency of the macroporous resin in various oils were also studied. Compared with the resin without macroporous structure, the maximum oil absorbency of the macroporous resin to the carbon tetrachloride (CCl4) was 28.28 g/g, which increased by 61.42%. Meanwhile, the saturated oil absorption time of resin also decreased significantly from 7.5 to 2 hr. The macroporous high oil absorption resin presents predominant performance of reuse and regeneration. Moreover, the macroporous resin had certain absorbency (8.7 g/g) to crude oil, which makes it useful for marine oil spill. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of Water Absorption and Resin Particle on Interfacial Shear Strength of CF/MAPP

In this study, effects of water absorption and adding resin particles around fiber on interfacial shear strength of carbon fiber (CF)/maleic anhydride grafted polypropylene (MAPP) were investigated. In water absorption test, CF/MAPP specimen was immersed in distilled water at room temperature for four weeks. Micro debonding test of water absorbed CF/MAPP was conducted. Micro debonding test of Resin particle added Carbon Fiber (RCF)/MAPP was also conducted. The resin particle size was less than 5μm. Fracture surface of RCF/MAPP was observed by using Scanning Electron Microscope (SEM). As a result, following conclusions are obtained. In case of water absorbed CF/MAPP, the interfacial shear strength decreased 34% compared with that of virgin. The reason is thought that the interface between fiber/matrix was weakened by absorbing water. In case of resin particle, interfacial shear strength of RCF/MAPP increased 34% compared with that of CF/MAPP. From fracture morphology of RCF/MAPP, resin particles on CF surface were found. Therefore, interfacial shear strength of CF/MAPP was increased by the friction on the surface of carbon fibers.

Preparation of thiacalix[4]arenetetrasulfonate-modified D201 resin and its adsorption of heavy metal ions

A thiacalix[4]arenetetrasulfonate-modified resin has been prepared by loading thiacalix[4]arenetetrasulfonate onto resins for the adsorption of heavy metal ions. Various factors affecting the adsorption capacities such as different resins, resin size, pH, contact time, and temperature were investigated by batch adsorption experiments, and the adsorption isotherms, thermodynamics, kinetics, selectivity, and regeneration were also studied. It was found that the loading capacity of the D201 resin (macroporous strong basic anion exchange resin) for thiacalix[4]arenetetrasulfonate was substantially higher than those of the D301 (macroreticular weak basic styrene anion exchange resin) and the 717 (strong base styrene anion exchange resin) resins and increased with decreasing particle size of the D201 resin. The adsorption kinetics followed the pseudo-second-order rate law for heavy metal ions, indicating that chemical sorption is the rate-limiting step of the adsorption mechanism. The adsorption of heavy metal ions onto the thiacalix[4]arenetetrasulfonate-modified resin was analyzed and was found to fit better to the Langmuir isotherm than to the Freundlich isotherm, and the maximum adsorption capacities were 78.1, 65.8, 54.3, and 49.8 mg/g for Cu2+, Zn2+, Cd2+, and Pb2+ ions, respectively. The prepared modified resin has high adsorption selectivity for heavy metal ions under the co-occurrence of alkali metal and alkaline earth metal ions. The regeneration efficiencies still exceed 90% after five cycles, indicating that the thiacalix[4]arenetetrasulfonate-modified resin could be favorably recycled.

Boron removal from water with fractionized Amberlite IRA743 resin

In this paper, the process of boron removal from water with fractions of Amberlite IRA743 resin of different particle sizes of 1–45, 150–180 and 500–700μm was studied over a boron concentration range of 1.5–15.0mg/L. The effect of the resin dosage, particle size, contact time between the resin and feed, solution pH and temperature, presence of side NaCl, Na2SO4 and MgCl2 salts on boron removal was studied. It was shown that the efficiency of boron removal increased with increasing pH, temperature, contact time and resin dosage while it decreased with increasing feed boron concentration and resin particle size. The side ions even at their high content in water did not affect the efficiency of boron removal. It was found that the pseudo-second order model describes well the kinetic data on boron removal from water with fine particles of Amberlite IRA743 resin indicating that boron sorption with the resin is limited by a rate of the solute complexation with N-methyl-d-glucamine functional groups. It was shown that the resin particles saturated with boron can be efficiently regenerated and reused after treatment with HCl or H2SO4 solutions followed by NaOH reconditioning.

Modified Empty Bed Residence Time Model for Copper Removal

The removal of copper ions from wastewater has been studied using ion exchange with an iminodiacetate resin. The effects of agitation time, pH value of the solution, and initial concentration of the copper solution have been evaluated. It has been found that the equilibrium is obtained after 72 h. Also, the capacity of the resin for the copper ions has been determined to be 2.2 mmol/g by measuring the equilibrium isotherm at a pH value of 5.0. When the pH value of the solution is lower than 3.2, the adsorption capacity of the resin is reduced drastically. It has been verified that the Langmuir-based isotherm models are the best-fit models for the equilibrium isotherm system. A series of fixed bed column runs have been performed to remove copper from solution and study the effects of solution flow rate, initial copper concentration, and resin particle size. The empty bed residence time model, EBRT, has been used to correlate the fixed bed pilot plant experimental results. The original form of the EBRT model was modified using a time dependent bed depth adsorption capacity to determine the bed exhaustion rate in order to improve the original model which utilized the equilibrium adsorption capacity. The modified model demonstrates that the EBRT can be used to more accurately model copper removal using the chelating ion exchange resin.

DRUG LOADING AND RELEASE PROPERTIES OF IONEXCHANGE RESIN COMPLEXES WHICH PREPARED BY BATCH PROCESS

Complexes of ion-exchange resins and Tramadol hydrochloride (TmH), a model drug, were prepared using a batch method with different functional groups, ion-exchange capacity, degree of cross linking, and resin particle size. Drug loading efficiency, release profiles, and scanning electron micrographs were also investigated. Most of the functional groups of resins were loaded with TmH after the completion of a double batch method and it was recommended for drug loading into the ion exchange resin. Using a batch method, drug loading could be monitored by simply measuring changes in the pH of the reaction medium since as complex formation reached completion, the pH returned to the initial pH of the eluent due to the limited amount of functional groups available for the exchange. TmH could be loaded up to the ratio of 1 (drug): 1 (resin), depending on the physicochemical properties of the resin. As the cross linking ratio and particle size increased, the drug loading and release rate decreased due to the reduced effective diffusion coefficient and surface area.

Separation of 1,3-Propanediol from Aqueous Solutions by Ion Exchange Chromatography

Abstract 1,3-propanediol is a promising monomer with many applications and can be produced by bioconversion of renewable resources. The separation of this product from fermentation broth is a difficult task. In this work, the application of cation exchange resin for the separation of 1,3-propanediol from model aqueous solution was examined. The best effect of separation of 1,3-propanediol from glycerol using sorption method was obtained for H+ resin form, although the observed partition coefficient of 1,3-propanediol was low. On the basis of the results of the sorption of 1,3-propanediol, the ionic forms of the resin were selected and used in the next experiments (H+, Ca2+, Ag+, Na+, Pb2+, Zn2+). The best results in ion exchange chromatography were obtained for cation exchange resin in H+ and Ca2+ form. The use of smaller particle size of resin and a longer length of the column allows to obtain better separation of mixtures.

Influence of glass particle size of resin cements on bonding to glass ceramic: SEM and bond strength evaluation

This study investigated the effect of the filler particle size (micron or submicron) of experimental resin cements on the microtensile bond strength to a glass-ceramic pretreated with hydrofluoric acid (HFA) etching or alumina airborne-particle abrasion (AA). Cements were obtained from a Bis-GMA/TEGDMA mixture filled with 60 mass% micron-sized (1 ± 0.2 µm) or submicron-sized (180 ± 30 µm) Ba-Si-Al glass particles. Ceramic blocks (PM9; VITA) were treated with 10% HFA for 60 s or AA for 15 s. Silane and adhesive were applied. Ceramic blocks were bonded to resin composite blocks (Z250; 3M ESPE) using one of the cements. Bonded specimens were sectioned into beams (n = 20/group) and subjected to microtensile bond strength tests. Data were analyzed using ANOVA and Student-Newman-Keuls' tests (5%). Failure modes were classified under magnification. Morphologies of the treated ceramic surfaces and bonded interfaces were evaluated by scanning electron microscopy. The HFA-submicron group had lower bond strengths than the other groups. All AA-submicron specimens debonded prematurely. Mixed failures were predominant for HFA groups, whereas interfacial failures predominated for AA groups. SEM revealed a honeycomb-like aspect in the HFA-treated ceramic, whereas the AA-treated groups showed an irregular retentive pattern. Continuity of cement infiltration along the bonded interface was more uniform for HFA-treated compared to AA-treated specimens. Cracks toward the bulk of the ceramic were observed in AA-treated specimens. Particle size significantly influenced the ceramic bond strength, whereas surface treatment had a minor effect.

Separation of tungsten and molybdenum using macroporous resin: Competitive adsorption kinetics in binary system

The method using macroporous resin has great potential in separating mixed solution containing a high concentration of both W and Mo. The competitive adsorption kinetics of W and Mo onto the macroporous weak base resin D301 was studied in the present work. Accordingly, the effect of several factors such as concentration, particle size and temperature was assessed on the adsorption kinetics and separation of these two metals. Back-scattering SEM and EDS line scan were performed to study the competitive adsorption behavior of W and Mo, particularly. The macroporous resin D301 exhibits a better selectivity towards W than Mo in the near-neutral solution. The decrease of resin particle size and the increase of temperature are found to increase the adsorption rate and reduce the time required for obtaining the optimum separation results. Furthermore, the adsorption kinetics of W can be expressed by the pseudo-second order model. Such model was successfully modified to describe the Mo adsorption kinetics which is significantly affected by W polyions. Diffusion process was identified as the mechanism controlling the rate of W and Mo adsorption.