Kinds Of Resins Research Articles

Analyzing the Design Parameters and Their Influence on the Tensile Strength of Composite Layers using Taguchi Technique

This study aims to establish the repercussions of distinct design parameters on the mechanical ability of composite laminates. For investigating the effects on mechanical characteristics of the composite layers, four design parameters were chosen: layering sequence, layering angle, resin kinds, and laminate thickness. A thorough analysis is done to determine the influence of a carbon layer in the layering sequence and the significance of different resins on the fastening tenacity of fibers, layering slant of fibers, and laminate thickness. The effect of the design, as mentioned above variable on tensile strength, has been investigated. Carbon and Glass fibers are noted for their high mechanical qualities and lightweight-to-strength ratio.The Taguchi approach was used to detect the vital design parameter for optimal mechanical abilities of the hybrid composite laminate. The L16 orthogonal array was created using the analytical software Minitab 17. Signal Noise (S/N) ratio charts were created in Minitab to study the impact of design elements on mechanical qualities. The numerical analysis was carried out with the help of the Analysis of Variance (ANOVA).The study’s originality is producing a Newly Discovered Resin named N.D.R.E. from the polyurea and polyethylene groups. In a comparative analysis, N.D.R.E. was compared to three standard resins (i.e., Epoxy, Polyester, and Vinyl Ester). The N.D.R.E. offers the fibers more fastening strength.For tensile strength, the single variable optimization yields the best sequence P1Q1R4S2 (i.e., layering Sequence CF/G.F./G.F./G.F., layering angle 00, resin type N.D.R.E., and thickness of laminate 3 mm). Resin and Layering angles are two crucial design parameters for the Tensile strength of composite laminates.

Experimental measurement of thermal conductivity of stereolithography photopolymer resins

The rise in the use of additive manufacturing highlights the importance of knowing the properties of the materials employed in this technology. Therefore, for the commercialization of thermal applications with this technology, heat management is essential. Here, computational modelling is often utilised to simulate heat transfer in various components, and knowing precisely the values of thermal conductivity is one of the key parameters. In this line of research, this paper includes the experimental study of three different types of resin used in additive manufacturing by stereolithography. Based on a test bench designed by researchers from the Public University of Navarre, which measures thermal contact resistances and thermal conductivities, the thermal conductivity analysis of three kinds of resin is carried out. This measuring machine employs the temperature difference between the faces and the heat flux that crosses the studied sample to determine the mentioned parameters. The thermal conductivity results are successful considering the constitution of the material studied and are consistent with the conductivity values for thermal insulating materials. The ELEGOO standard resin stands out among the others due to its low thermal conductivity of 0.366 W/m K.Article HighlightsCalculating thermal conductivity of three resins used in additive manufacturing by stereolithography.Contributing to a knowledge-based design of heat sink in thermal conductivity measurement bench.Improvement of the thermal conductivity measurement bench by reducing the uncertainty for its application in low thermal conductivity materials testing.Graphical abstract

Enhanced toughness and degradable ability of polybenzoxazines/polyhexahydrotriazines interpenetrating polymer networks by sequential cure method

Benzoxazine resins are widely used as matrix resins of composites in the aerospace industry. For example, auxiliary power units and center bodies of an aircraft are usually made by polybenzoxazine composites, and these parts should be replaced periodically for aviation safety. So, resins used in this field would better be strong and economically maintainable. However, traditional polybenzoxazines, which are formed by irreversible crosslinked networks, show brittle and undegradable. These two disadvantages may not only cause component malfunction but also huge maintenance costs. Considering these two points above, we developed a new kind of resin by employing an interpenetrating polymer network (IPN) structure into polybenzoxazine. A series of IPNs were prepared using 3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazine-6-carbaldehyde (HB) and poly-(hexahydrotriazine) (PHT), by thermal polymerization. Various proportions of these two monomers were studied and their mechanical, thermal, and degrade properties were characterized. Fourier transform infrared spectrometer (FTIR) proves that intermolecular H-bonds (OH⋯O) exist between PHB and PHT, which facilitate the formation of homogeneous phase in IPNs. Tension test results show that mechanical properties especially the toughness of these IPNs increase sharply. The minimums of tensile strength and breaking elongation we acquired are 94.29 MPa and 5.63%, respectively, which exhibit 180% and 250% higher than those of pure PHT. In addition, we find that when the molar ratio of PHB/PHT is 2.4, tensile strength of the polymer (PHB/PHT-2.4) exhibits a highest value of 122.75 Mpa, and breaking elongation reaches 9.60%. At the same time, it shows the highest glass transition temperature (Tg) of 211 °C by dynamic thermo-mechanical analysis (DMA), compared with PHT and IPNs of the other proportions. Additionally, PHB/PHT IPNs exhibit a good solution degradability, when immersed for 36 h in a mixed solution, which was prepared by hydrochloric acid/tetrahydrofuran (1:4) mixed solvent. IPNs prepared by PHB/PHT could be totally broken in the solution above, except for PHB/PHT-4.8.

MRNA Purification: Technology Aspects and Impurities TFF, Chromatography, UF/DF (Resins, Magnetic Beads, Monoliths)

m RNA VACCINE production like other biopharmaceutical need various purification stages in the manifacturing process. In this process are used techniques like: (TFF) tangential flow filtration followed by different chromatographic procedure (affinity and ion exchange separation) with various kinds of resin and then UF/DF technique (Ultrafiltration-diafiltration). So it is of interest to verify that the materials used for this kind of procedure is solid phases or for the membrane and if released impurity in the final product. For Silica-based Reversed-Phase packing’s, a carbon load percentage indicates the amount of functional bonded phase attached to the Silica-base material. Aim of this work is to investigate the role played by these characteristics in the separation process of mRNA. Because this parameter influence the retention time it is interesting to evaluate the use in separation technique of biopharmaceuticals and this also is for the carbon coated silica columns. Silica gel for chromatography can be produced by systemic process but also form Rice treated at high temperature. What kind of effect can be played using an high level of carbon coated silica material on the final purified product? The graphitic particle can be found as impurity during the manufacturing process of these resins? And what is the role played by carbon (graphene-quantum dots) membrane as reported in various research application?

Thermosetting resins from a tetra‐functional vinylbenzene compound possessing cyclic siloxane cores

AbstractCyclic siloxane is an attractive building block for incorporation of silicon‐containing units as well as their distinguished properties to polymer materials. This work reports the synthesis and characterization of a tetra‐functional vinylbenzene compound possessing cyclic siloxane cores (cD4‐4VB). Synthesis of cD4‐4VB is carried out using cD4‐4SiH as the reactive precursor and multiple‐step reactions, including hydrosilylation, deacetylation, and SN2 substitution. cD4‐4VB is an effective monomer for preparation of the corresponding cyclic silicon‐based thermosetting resins (CR‐cD4‐4VB). CR‐cD4‐4VB shows attractive film formability and good thermo‐mechanical properties, including a storage modulus of 2.0 GPa, a glass transition temperature of 282°C, a thermal stability above 400°C, a high char yield (at 800°C in nitrogen) of 55 wt%, and a dielectric constant of 3.12 at 10 GHz. This kind of resins have potential of application for halogen‐free flame retardants and high‐performance polymer films.

Thermoset Polymer Matrix Composites of Epoxy, Unsaturated Polyester, and Novolac Resin Embedding Construction and Demolition Wastes powder: A Comparative Study.

Composite materials that consisted of a polymer resin as matrix (PMCs), filled using construction and demolition (C&D) wastes powder of different grain sizing in micro-scale were manufactured and studied. Three different kinds of resins were used as the matrix for the purposes of this study. More specifically, composites made of epoxy and unsaturated polyester resins purchased from the market and phenolic resin (novolac) laboratory synthesized, were produced. The morphological and elemental analysis of these materials was performed through scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Additionally, mechanical performance and thermal insulating efficiency of these materials were examined through bending and shear strength tests according to the three-point method and via determination of the thermal conductivity coefficient λ. C&D wastes have undergone the appropriate processing in order to prepare filling products of the required granular size in pulverized form. In this research study, construction and demolition waste-based thermosetting polymer composites were produced with flexural strength in the range 20–60 MPa, shear strength in between 1–8 MPa, and thermal conductivity coefficients in the range of 0.27–1.20 W/mK. The developed materials embedded 30–50% w/w C&D wastes, depending on the resin used as the matrix.

Hapten-Branched Polyethylenimine as a New Antigen Affinity Ligand to Purify Antibodies with High Efficiency and Specificity

Purification of antibodies has become a critical factor in antibody production. A high-purity specific antibody against antigens, especially small molecules, seems to be difficult to obtain, even with the help of a protein A affinity column, which is a conventional and broadly used ligand for the separation of antibody and non-antibody proteins. Therefore, it is urgent to develop a cheap, simple, efficient, and stable method to separate the specific antibody from other antibodies. In this study, to improve the sensitivity and accuracy of immunoassay results, enrofloxacin (ENR) was grafted onto polyethylenimine (PEI) by the abundant amino groups and then the whole ligand (ENR-PEI) was conjugated to CNBr-Sepharose 4B to prepare the affinity column for the purification of the specific antibody against ENR from polyclonal antibodies. Scanning electron microscopy and Fourier transform infrared spectroscopy verification showed that Sepharose 4B was successfully modified by ENR-PEI with excellent uniformity. The capacity of the prepared column could reach to 6.15 mg of specific antibody with high purity per milliliter resin due to the high coupling ratio (49.3:1) of ENR on PEI, and the IC50 value of the antibody after purification was 47.58 ng/mL with a lowest limit of detection (IC10) of 1.099 ng/mL-18 times lower than those of the antibody purified through the protein A column. All the results showed that this new kind of resin could be used as the potential ligand in the purification of the trace-specific antibody against antigens in complex mixtures with high efficiency and specificity.

Carbon dots for epoxy curing: Anti-forgery patterns with long-term luminescent stability

Here, we demonstrate that pristine CDs, obtained from amine-containing precursors, were available for the curing of epoxy monomers. The optical properties and the surface chemical functionality of the CDs depended on the nature of the precursors. The CDs showed good compatibility with the epoxy monomer before and during the curing reaction, which led to their uniform dispersion in the epoxy matrix. In addition, it was found that the direct growth of the epoxy chains on the CD surface led to the effective passivation of the CDs. The CD/epoxy nanocomposites showed retentions of more than 80% in PL intensity even after 8 weeks of storage in ambient conditions. Together with those beneficial properties, the CD/precursors were readily patterned or printed on various substrates. The chemical components of the luminescent CDs are similar with the epoxy matrix and furthermore are common in various organic substrates, prohibiting reverse engineering. The combination of the CD/epoxy resin showed strong potential for stealth patterning and printing to enhance anti-forgery protection. Importantly, the use of CDs as curing agents can be further extended to other various kinds of resins.

Mechanical Properties Improvement in Highly and Aligned Dispersed Graphene Oxide/Bismaleimide Nanocomposites based on Graphene Oxide Sponge

Graphene oxide (GO) as an excellent nanofiller is widely used to improve the mechanical properties of the resin matrix. The dispersion and distribution of GO sheets in the resin matrix have a strong impact on the mechanical properties of composites. Based on the action principle of GO sponge, a simple method for solving the highly and aligned dispersion of GO in the bismaleimide (BMI) resin is investigated. The GO bulk prepared by vacuum infusion using a porous GO sponge as a frame is smashed in the resin by the large shear force generated through the high‐speed stirring method. It is found that GO sheets have a highly dispersion in the BMI resin. A sample and new method for preparing GO aligned dispersion in resin by large deformation is provided to further enhance the mechanical properties of the resin. As expected, the flexural strength and flexural modulus of GO/BMI nanocomposites are enhanced by 39.6% and 45.5% than BMI resin. This simple dispersion method is easier to generalize to solve the dispensability of GO in other kinds of resins. In the future, there will be a broader application prospect in engineering applications.

Deep-Discharge Performance of Lead Acid Battery Using Graphite Based Composite As Cathode Current Collector

Introduction Lead Acid Batteries (“LAB”) have been widely used for more than 100 years. LAB cannot be recharged after over-discharged, and its performance is greatly declined. Iwai et al. have found that the above deterioration is caused by the formation of α-PbO2 on the surface of cathode active material β-PbO2 due to the reduction by local cell reaction. They also have revealed that the formation of α-PbO2 can be prevented by using gold or platinum as cathode current collector. At that case, the LAB can be recharged even after over-discharge.[1,2] We revealed, furthermore, that LAB using graphite sheet as cathode current collector also has high resistance to over-discharge.[3] This LAB can charge/discharge without performance degradation even after full discharge followed by 48 h rest period. In order to improve sulfuric acid resistance, we tried to mix four kinds of resin (polyethylene, polypropylene, ethylene propylene copolymer and fluororesin) to the graphite sheet. It is revealed that the weight of graphite sheet did not increase by immersion test into sulfuric acid for more than or equal to 5 wt% polypropylene mix, and that surface electrical resistance of the sheet did not increase for less than or equal to 5 wt% polypropylene mix.[4] We decided to use graphite sheet with 5 wt% polypropylene as cathode current collector. For this LAB, we have investigated long term charge deep-discharge cycle performance including various kinds of rest-period. We also investigated the rechargeablity after 0V discharge followed by various long rest period. Experiment We made the resin-dispersed graphite sheet in order to improve electrolyte repellency compared to normal graphite sheet. We used polypropylene for resin material and dispersed it by 5 wt% into expanded graphite, then we made it into sheet by rolling mill. The heat treatment was preheating at 100℃ for 10 min and then at 180℃ for 10 min to disperse resin evenly.We used two-electrode glass cell for charge/discharge experiments. The cathode active material was prepared by mixing β-PbO2 powder, acetylene black and PTFE at the ratio of 80:15:5 in weight. We added acetylene black as a conductive additive and PTFE as a binder. The cathode was made by pressing the paste on a current collector. We used 35% H2SO4 as electrolyte and lead plate as anode.First experiment is the long term deep-discharge durability test. The cycle was consisted of 4 times of discharge down to 0V and full charge, and then 48 h rest period. Charge/discharge rate was 180 mAg-1 for charge and 9 mAg-1 for discharge. The stabilization cycle prior to deep-discharge was consisted of 20 cycles of discharge at 9 mAg-1 for 30 min and charge at 180 mAg-1 for 20 min. We determined charge and discharge rates by weight of cathode active material.The second experiment is to evaluate durability against over-discharge followed by various rest period. After the stabilization cycle, we discharged the cell down to 0V and kept it in open-circuit for various period, and then rechargeablity was examined by charging the cell. Results and discussion Fig.1 shows the result of the first experiment. The LAB using 5 wt% polypropylene-dispersed graphite sheet current collector continued the cycle of 4 times charge/deep-discharge and 48 h rest for more than 5 months. The cause of the breakage of the cell after 5 months was due to fall of active material off the current collector. It is thought that this cell could charge/discharge for longer term by improving the filling method of active material. This result shows that this type of battery has high durability to deep-discharge for long term.Fig.2 shows the result of the second experiment. The rest period was 2 d or 1 week. It was found that the cell was rechargeable for either rest period. It was confirmed that The LAB using 5 wt% polypropylene-dispersed graphite sheet current collector has high durability to both over-discharged and long term rest.

Solar Heat Reflective Coating for Sidewalks Considering Cooling Effect, Anti-Skid Performance, and Human Comfort

Abstract The solar heat reflective coating for sidewalks (SHRCS) is investigated in the present article. Compared with the reflective coating for the traffic lane, the reflective coating for the sidewalk has low requirements for abrasion resistance but high requirements for human comfort. Therefore, cooling characteristics, anti-skid performance, abrasion resistance, and sports performance are chosen to assess SHRCS. SHRCS consists of three layers, the bottom layer, the elastic layer, and the surface layer. The materials of the three layers were determined. Particularly, because the surface layer is composed of resin, functional materials, and pigments, the suitable surface resin was chosen from five kinds of resin, and the Taguchi orthogonal array design method was used to determine the optimal mix ratio of the surface layer materials. The in situ test shows that the surface of the road using SHRCS can be cooled by 5.9°C versus the original road surface. The temperature difference of the skin surface between standing on the coated and uncoated road can reach 1.6°C. In the end, the sports performance characteristics of SHRCS, such as the vertical ball rebound, were tested.

New Thermoplastic Damping Polymeric Materials Based on Ethylene-Vinyl Acetate

This article is devoted to the problem of working out of damping polymer materials which are effective in the wide temperature and frequency range. In the modern world, work is being carried out to create damping polymer composite materials (DPM) from which it is possible to manufacture protective elements and parts of engineering structures of reduced vibration excitability. Existing DPM have a narrow temperature range, within which effective vibration absorption is observed, moreover, most of them go through a vulcanization stage, which increases the cost of the final product, has a harmful effect on environment and allows limited recycling of waste. One of the ways to solve this problem is to replace traditional rubber vibration-absorbing materials with thermo-elastoplasts (TEP). The most promising polymer for TEP is ethylene vinyl acetate (EVA), which has high damping properties, oil resistance and relative incombustibility. In this regard, experimental studies were conducted to establish the patterns of influence of the type and concentration of structure-forming components (plasticizers, fillers, modifiers) on the dynamic mechanical properties of TEP based on EVA in order to develop a new DPM effective in a wide temperature range. The leading method to investigate this problem is a method of dynamic mechanical analysis which allows to get information about changes of mechanical characteristics under mechanical load and controlled temperature and frequency. With the help of detected patterns it was possible to determine type of plasticizer which significantly decreases glass temperature of EVA. The percentage ratio of EVA/plasticizer system is stated, and the type of plasticizer at which the maximum of mechanical losses takes over greater values is accordingly detected. It is revealed, that to work out DPM on EVA basis, which are effective in wide temperature range it is more preferable to add not less than 40 % on volume basis inert fillers, such as talc or mica with addition of 5-10 % of carbon as the hardening additive. The kind of resin improving damping properties and raising rigidity of composites on EVA basis is defined. On the basis of the research, a material was developed which has the following properties: the maximum value of tan δ is at least 0.45 at a temperature of plus 5�C (oscillation frequency 10 Hz); width of the temperature interval within which tan δ is not less than 0.3 from minus 40 to plus 50�С (oscillation frequency 10 Hz); conditional tensile strength of not less than 10 kg/cm2, cold resistance up to minus 50�C.

Characterization of effective permeability of prepreg fibers under autoclave molding process conditions using process model simulations

During autoclave molding process of prepreg composites, resin flow occurs through the fibers in the transverse direction of the layup due to applied external pressure. The extent of resin flow depends largely on the permeability of the reinforcement used in prepreg, and hence, the permeability is an important parameter for process modeling and simulations of composites fabrication processes. Most of the existing methodologies for measurement of transverse permeability of the reinforcements described in the literature are based on experimental techniques. However, the permeability measured through these experiments differs greatly from the actual permeability of the prepreg during actual fabrication process. This article focuses on this aspect and a methodology for the prediction and measurement of saturated transverse permeability of fiber preform of prepregs as encountered during fabrication is reported here. The methodology takes into account the actual process conditions and simulates them to predict permeability of the reinforcement. The permeability thus obtained will be the ‘effective permeability’ of the reinforcement. The methodology is applicable for prepregs containing any kind of resin, reinforcement and its weaving architecture.

Analysis of wear properties of granite dust filled polymer composite for wind turbine blade

Efficient usage of wind energy by establishing a suitable material for wind turbine blade is considered in this paper. Aluminium alloys and coated timber were used as blade material in the early stage and are discarded for various reasons including their life time and their efficiency. New polymer based materials such as Carbon fiber, Glass fiber, and Aramid fiber with different kinds of resins are being used as wind turbine blade material these days. As a new trend, granite dust is filled with the polymer material to improve its qualities like hardness and durability. It is tested for wear properties in Air jet erosion tester by varying the angle of impingement keeping other factors constant. Its mechanical properties like tensile stress, hardness and density values are calculated and plotted in graphs. The obtained results demonstrate how the wear properties of these samples changed with the impingement angle.

Secondary Bonding Strength Evaluation of FRP Laminated Plates

We focused on common secondary bonding method that usually applied on manufacturing of FRP yacht, and discussed the secondary bonding strength according to experimental results. The hulls of FRP yacht is made using VARTM, and then the secondary bonding procedures are used to reinforce the hull structures using hand lay-up. The different kinds of resin and different surface treatment methods were considered in this study. Generally, the resin manufacturers always suggested that the secondary bonding procedure can be performed directly after the separation media is released. Therefore, we discussed the bonding strength of different kind of surface treatments, likes grinding, surface sizing, surface-active etc. Finally, the experimental results shown that: 1. The effect of surface sizing is obviously poor than the other surface treatments; 2. The surface-active agent plays a good joint strength on unsaturated polyester resin; 3. Whether the secondary bonding surface is grinded or not, the bonding strengths are not much different.

Investigating the origins of acute and long-term toxicity posed by municipal wastewater using fractionation

ABSTRACT It has been proven that the raw wastewater, secondary effluent and even reclaimed water may have toxic effects on aquatic organisms. In the present study, fractionation procedures combined with bioassays using luminescent bacteria were conducted to identify the fractions that contributed to the acute and long-term toxicity of municipal wastewater. Solid phase extraction was used to divide dissolved organic matter from the wastewater into three fractions, including non-polar, medium-polar and polar fraction. Among these fractions, although the acute toxicity of municipal wastewater was mainly caused by polar and medium-polar chemicals, the acute toxicity induced by the unit mass of the medium-polar fraction was the greatest. Using three kinds of resins, the organic substances in municipal wastewater were classified into six fractions, and the long-term toxicity of these fractions was further identified. The long-term toxicity of the hydrophobic neutrals, which were the primary toxic substances in raw wastewater, decreased after the conventional secondary biological treatment. Hydrophilic neutrals, which accounted for the majority of organic substances in the secondary effluent, were the main substances with long-term toxicity in the secondary effluent. The identification of fractions with acute and long-term toxicity in municipal wastewater is beneficial for further treatment to attenuate the ecotoxicity of wastewater before discharge into the aquatic environment.

Experimental Study on Gas Evolution Process of Binders in Foundry Industry based on TG-MS

The gas evolution performance of the mold is a very important index, which is directly related to the quality of casting. As the gas generation of sand is much smaller than that of binder, the gas evolution process of binders plays a decisive role in the formation of defects such as pores during casting. Therefore, it is of great significance to study the gas evolution process of binders in foundry. In this study, TG-MS analysis will be introduced into the study of the gas evolution process of binders in foundry. Three kinds of resins in foundry and one kind of sodium silicate will be selected, and the binders will be tested by TG-MS after being hardened to find and analyze the types and temperatures of gassing in the heating process. This study helps to find out the regular pattern of gas evolution process of binders in foundry and to provide theoretical and practical guidance for the study of casting defects such as pores.

Evaluation of resin composites for dental restorations

In the production of dental restorations, there are, currently, two main types of materials: ceramics and resin composites. These latter kinds are typically suggested because of their quick fabrication, easy reparation and increased crossed link density compared with conventional light-cured materials. However, it is not clear for the specialist what is the best option among the many commercially available materials for each precise clinical case. For that reason, this work aims to clarify the real mechanical performance of resin-based composites for indirect dental restorations obtained by material removal processes and their most suitable application.Two kinds of resin CAD/CAM blocks were selected: LavaTM Ultimate and CerasmartTM, which were tested under two conditions: in the as received by the manufacturer state and after storage in artificial saliva during 30 days. The mechanical properties of both materials were analysed (density, hardness, flexural strength, fracture toughness) but also the influence on the degradation of the mechanical performance due to the contact with the saliva.Results indicate a better mechanical performance of the Lava Ultimate material in the as-received condition, despite its coarser microstructure. However, Cerasmart shows a stabilised microstructure with a smaller degradation of the mechanical properties in contact with the artificial saliva; in other words, improved durability inside the mouth.

Partial bio-based poly (aryl ether ketone) derived from 2,5-furandicarboxylic acid with enhanced processability

The bio-based high-performance engineering plastics poly (aryl ether ketone) are required to be prepared with the threats of increasing shortage of petroleum resources. In this work, a novel green bio-based poly (aryl ether ketone) (PFBEK and PFDEK) based on the bio-based monomer 2,5-furandicarboxylic acid have been successfully synthesized via the nucleophilic aromatic substitution polymerization. The fossil-base polymers PDBEK and PDDEK were prepared as comparison. The chemical structures of the resins were investigated in detail by 1H NMR and FTIR. WAXD measurements revealed that all the polymers presented amorphous structures. The Tg of PFBEK and PFDEK are slightly decline when compared with the corresponding petroleum base resin due to the fractional free volume (FFV) increased by the nonlinear structure of the furan as confirmed by computer simulations. The results of thermal degradation kinetics showed that the thermal stability of the resin decreased when furan replaced phenyl. Nevertheless, the bio-based resins (PFBEK and PFDEK) still exhibited excellent thermal stability. Rheological test revealed that the viscosity of bio-based resins has significantly decreased compared with petroleum base resins. Hence, the new bio-based polymer can be processed at a lower temperature. Besides, the mechanical properties of PFBEK and PFDEK are comparable to the corresponding petroleum-based resins. Moreover, all the polymers showed outstanding solubility in organic solvents, such as NMP, DMAc and so on. Consequently, these two kinds of resins with excellent mechanical properties and processability, which is greener than petroleum base resins, meeting the requirements of sustainable development and can be potential to substitute the petroleum-based resins.

Adsorption and desorption behavior of anion-exchange resin towards SO42− in the desulphurization process using citric method

The application of weak-base anion-exchange resin for removal the SO42− from the citrate solution to guarantee its good performance for adsorption of SO2 is proposed in this work. The weak-base anion-exchange resin that has prior adsorption towards SO42− compared with citrate, allows the effective removal of such impure anion. We initially chose four kinds of resins, namely D301R, D301G, D370 and D315, to investigate their behavior upon SO42− adsorption and then determined D301R and D315 to give a comprehensive understanding towards their adsorption performance in various condition. Results indicate that D315 possessing better adsorption ability than D301R could be a potential candidate for SO42− removal from the citrate acid solution during the desulphurization process using citric method. The pretreatment of protonation for resins could effectively facilitate their adsorption behavior towards SO42− under the same pH condition. Moreover, we assume that the protonated D315 would meet the practical requirement well given its good performance.