Resin Treatment Research Articles

Microstructure evolution and decomposition behavior of an novel core-multi-shell structure TiH2 foaming agent

Al foams have received an increasing attention due to their light weight, high specific strength, energy absorption, sound absorption, damping and electromagnetic shielding. However, the issue of low mechanical property is still a challenge due to the mismatch between the melting point of Al and Al alloys and the decomposition temperature of TiH2 blowing agent. In this work, an novel TiH2 foaming agent with core-multi-shell structure (TiH2/Ti3O@TiO2/BPR) was prepared by thermal oxidation and coating boron phenolic resin (BPR) treatment. The results showed that the composite layers of Ti3O@TiO2 with a thickness about 70 nm and BPR with a thickness about 200 nm were formed on the surface of TiH2 particles which can act as an excellent thermal and diffusional barrier to retard the heattransfer and delay the release of hydrogen. Compared with as-received and pre-oxidized TiH2 particles, TiH2/Ti3O@TiO2/BPR particles exhibited an excellent slow release property and its peak temperature of hydrogen release and corresponding time are about 647 °C and 1801 s, which increased by about 83 °C and 176 s, 44 °C and 59 s, respectively. The hydrogen release temperature matched well with the melting point of Al and Al alloys, which is very suitable for preparing high quality Al foams.

Impact of Resin Treatment on the Crystallinity of Finished Cotton

Polymer Science: Peer Review Journal Impact of Resin Treatment on the Crystallinity of Finished Cotton Nasr Litim*, Ayda Baffoun and Saber Ben Abdessalem Textile Materials and Processes Research Unit MPTex, National Engineering School of Monastir University of Monastir, Tunisia *Corresponding author: Nasr Litim, Textile Materials and Processes Research Unit MPTex, National Engineering School of Monastir University of Monastir, Monastir 5019, Tunisia Submission: February 12, 2022;Published: February 24, 2022 DOI: 10.31031/PSPRJ.2022.03.000556 ISSN: 2770-6613 Volume3 Issue2

Evaluation of radiological safety according to accident scenarios for commercialization of spent resin mixture treatment device

Spent resin often exceeds radiation limits for safe disposal, creating a need for commercial-scale treatment techniques to reduce resin radioactivity. In this study, the radiological safety of a commercialized spent resin treatment device with a treatment capacity of 1 ton/day was evaluated. The results confirm that the device is radiologically safe in the event of an accident. This device desorbs 14C from the spent resin, allowing disposal as low-level waste instead of intermediate-level waste. The device also reduces overall waste by recycling the extracted 14C. Potential accident scenarios were explored to enable dose assessments for both internal and external exposure while preventing further spillage of the device and processing the spilled resin. The scenarios involved the development of a surface fracture on the resin mixture separator and microwave systems, which were operated under pressure and temperature of 0–6 bar and 0–150 °C, respectively. In the case of accidents with separator and microwave device, the maximum allowable working time of worker were derived, respectively, considering external and internal exposures. When wearing the respirator corresponding to APF 50, in the case of the microwave device accident scenario, the radiological safety was confirmed when the maximum worker worked within 132.1 h.

Recent Advances in Fenton-Like Treatment of Radioactive Ion Exchange Resins

Recent Advances in Fenton-Like Treatment of Radioactive Ion Exchange Resins

Исследование осушки и оптимизация кондиционирования отработавших ионообменных смол без включения в матрицу для захоронения

The publication [1] discusses technical issues faced during the conditioning of intermediate- and low-level spent ion exchange resins by thermal vacuum drying to obtain packages that would meet waste acceptability criteria for nearsurface disposal facilities. This article is a continuation of another publication [1] which elaborated on a study of ionexchange resin drying process and provided some proposals on the conditioning optimization using NZK-150-1.5 P containers. It specifies optimal parameters for the pre-disposal treatment and conditioning of dried resins providing their safe storage and disposal. The study presents calculated permissible internal pressure providing adequate strength of the containers. The proposed pre-disposal ion exchange resin treatment and conditioning method can be recommended for industrial use.

Effect of post-polymerization with autoclaving treatment on monomer elution and mechanical properties of 3D-printing acrylic resin for splint fabrication

ObjectivesTo evaluate the effect of post-treatment autoclaving on monomer elution and mechanical properties of three-dimensionally (3D) printed resin for splint fabrication. MethodsPhotopolymer resin specimens (Dental LT Clear) were 3D-printed and processed according to the manufacturer's instructions. The specimens were randomly divided to different post-treatment protocols: water storage, autoclaving at different temperatures (121 °C or 132 °C), times (4 or 30 min) and no treatment as a control. The elution of UDMA, HEMA, and EGDMA monomers was determined using high-performance liquid chromatography (HPLC) by immersing the specimens in 75% ethanol for 72 h. The flexural modulus, surface microhardness and linear dimensional changes were measured. The monomer elution and flexural modulus were statistically analyzed using Welch's ANOVA followed by Dunnett's T3 tests, while the surface microhardness and dimensional changes were analyzed using one-way ANOVA followed by Bonferroni tests (α = 0.05). ResultsThe overall monomer elution concentrations were significantly highest for the control group and lowest for specimens treated in an autoclave at 132 °C for 4 min. The flexural modulus was not significantly different between all groups. The surface microhardness was significantly higher for all autoclaved groups than the control and water storage groups. The linear expansion was significantly higher after post-treatment autoclaving in contrast to water storage. Significance/conclusionsPost-polymerization autoclave treatment of the 3D-printed resin reduced monomer elution and improved surface microhardness without deteriorating the flexural modulus. Post-treatment with an autoclave at 132 °C for 4 min can be recommended for 3D-printed resin for splint fabrication.

Study on the mechanisms of epoxy resin gasification in supercritical water by molecular dynamics and experimental methods

Epoxy resin is a common polymer in electronic wastes. Improper disposal may lead to secondary pollution and threaten the environment and human health. Supercritical water gasification (SCWG) technology, as a clean and efficient epoxy resin treatment and decomposition technology, has a good application prospect. In order to clarify the gasification mechanism of epoxy resin in supercritical water (SCW), the effects of different reaction parameters on the gasification characteristics of SCW were analyzed by using molecular dynamics (MD) and experimental methods. It was found that higher reaction temperature, longer reaction time, and lower material concentration are more conducive to the decomposition of epoxy resin in SCW. In addition, the SCWG process of epoxy resin was simulated by the MD method. The decomposition pathway of epoxy resin molecules in SCW and the generation pathway of H2 were explored, and the mechanism of the SCWG process of epoxy resin was studied, which will provide theoretical guidance for further research on the improvement of gasification efficiency of epoxy resin in SCW.

Field demonstration of coupling ion-exchange resin with electrochemical oxidation for enhanced treatment of per- and polyfluoroalkyl substances (PFAS) in groundwater

This pilot-scale field demonstration evaluated the remediation of poly- and perfluoroalkyl substances (PFAS) from groundwater contaminated with aqueous film-forming foam (AFFF) from a coupled regenerable ion exchange resin (IXR) and electrochemical oxidation (EO) treatment train. A pilot-scale IXR system was used that incorporates a novel resin regeneration process, and recovers and reuses the majority of the regenerant solution using distillation. The pilot system removed PFAS from ∼1,000,000 L (approximately 260,000 gallons) of contaminated groundwater from a fire training area, and treated effluent from the IXR system was non-detect for PFOA and PFOS. The concentrated waste stream (i.e., still bottom) from IXR was treated on-site by an EO system with Ti4O7 electrodes, achieving 80–98% destruction of PFOA and PFOS. The surface area normalized first-order rate constants (kSA) were 3.96 × 10−7 m s−1 and 7.92 × 10−7 m s−1 for PFOA and PFOS, respectively, with short-chain perfluoroalkyl acids (PFAAs) identified as intermediate degradation products. Based on the fluoride recovered and PFAS mass loss measured at the end of EO treatment, fluoride release ratios were 130% for still bottom sample 1 (SB1) and 215% for still bottom sample 2 (SB2), indicating mineralization of unquantified fluorinated compounds in the waste stream. Overall, the electric energy consumed per order of magnitude reduction in concentration (EE/O) for treating PFOA and PFOS in groundwater by the IXR-EO treatment train was 0.131–0.161 kWh/m3 for PFOA and 0.071–0.094 kWh/m3 for PFOS, which was orders of magnitude lower than the reported EE/O values for stand-alone electrochemical treatment. The results of this field demonstration show the promise of coupling regenerable IXR with EO for cost-effective removal, concentrating, and destroying PFAS from groundwater.

Life cycle environmental impacts of regeneration options for anion exchange resin remediation of PFAS impacted water

Although anion exchange resin (AER) treatment is considered an effective technology for removing per- and polyfluoroalkyl substances (PFASs) from impacted water, the environmental impacts associated with AER regeneration have not been systematically explored. In particular, the trade-offs of altering the composition of the regeneration solution and disposing of or recycling the waste regeneration solution are not known. To fill these important gaps in the literature, this research conducted a comparative life cycle assessment (LCA) of an AER-based PFAS remediation system with different regeneration scenarios including disposing of waste regeneration solution via incineration, reusing the organic cosolvent and brine fractions of the waste regeneration solution, and altering the composition of the regeneration solution to avoid organic cosolvent or NaCl. The results show that disposing of waste regeneration solution via incineration, without recycling organic cosolvent or brine, had the greatest environmental impact, and that incineration accounted for the greatest impact among contributing processes. Recycling of the cosolvent (or cosolvent and brine) fraction of the waste regeneration solution resulted in lower environmental impacts due to reduced mass of waste disposed of via incineration. Replacing NaCl in the brine with an alternative salt resulted in higher environmental impacts, with salts derived from chemical production, such as ammonium chloride and potassium carbonate, showing the largest increases in impacts. The results of this research highlight the importance of understanding the fate of PFASs during incineration, and the need for PFAS destruction technologies that can be coupled to AER regeneration to avoid incineration.

Fabrication of Hydrogen Boride Thin Film by Ion Exchange in MgB2.

In this study, hydrogen boride films are fabricated by ion-exchange treatment on magnesium diboride (MgB2) films under ambient temperature and pressure. We prepared oriented MgB2 films on strontium titanate (SrTiO3) substrates using pulsed laser deposition (PLD). Subsequently, these films were treated with ion exchangers in acetonitrile solution. TOF-SIMS analysis evidenced that hydrogen species were introduced into the MgB2 films by using two types of ion exchangers: proton exchange resin and formic acid. According to the HAXPES analysis, negatively charged boron species were preserved in the films after the ion-exchange treatment. In addition, the FT-IR analysis suggested that B-H bonds were formed in the MgB2 films following the ion-exchange treatment. The ion-exchange treatment using formic acid was more efficient compared to the resin treatment; with respect to the amount of hydrogen species introduced into the MgB2 films. These ion-exchanged films exhibited photoinduced hydrogen release as observed in a powder sample. Based on the present study, we expect to be able to control the morphology and hydrogen content of hydrogen boride thin films by optimising the ion-exchange treatment process, which will be useful for further studies and device applications.

Studies on Blending of Cotton with Polyester Part II. Utilization of Chemcally Treated Cotton in Blending with Polyester for Better Properties.(Dept.T)

Trials have been made to make use of a light microscope and swelling solution to explain the reduction of strength and breaking extension after resin treatments. The results obtained are in full agreement with earlier postulation. The latter ascribed the loss in strength properties to stress concentration by crosslinking and oelleuloss degradation by the casalyst used in resin treatment.

Improving ballistic performance of Kevlar fabrics by resin treatment

The aims of our investigation are to increasing inter-yarn friction by using polyurethane resin for superior ballistic protection without affecting the weight. In our concentration, we have used three different resin impregnated (25 × 25 cm) (Type-A), (4.5 × 4.5 cm) (Type-B), (9 × 9 cm) (Type-C) structure to treat our Kevlar fabrics and 12% wt. PU solution as resin. Grounded on our three different resin-impregnated fabric, we have been evaluated the weight increase percentage to analyze our core objectives maintaining the less weight escalation ratio with better ballistic performance. As the resin impregnation amount increases, the yarn or fiber dimensions lead to fabric stiffness. Later on, the yarn pull-out installation was created and the yarn (single and multiple) pullout tests were performed on both plain and resin impregnated structures to find the differentiation. The result of the investigation shows high-density resin-impregnated fabric indicates a higher pull-out force contrasted with those of low-resin impregnated fabric structure. Fabric displacement at max. Force during multiple-end pull-out indicated a higher fabric displacement (mm) rate contrasted with that of the single pull-out. Optical microscopic examination is done to observe the progressions on pulled out regions. During our observation, no implication variety was found in the surface at a specified loading rate except adjacent yarn displacement grounded on the amount of yarn pulled out. Utilization of resin impregnation builds the commitment of more yarns as the slippage of yarns is limited thus leads to the higher energy required rate. Finally, by ballistic perforated impact parameters, it is affirmed that expanding inter-yarn friction can improve ballistic performance of fabrics. Ultimately, it is concluded in the way that these new ballistic resin-impregnated structures come up with higher inter yarn friction, low expense, less weight, considerable stiffness of the fabric and the reliable ballistic performance on the finished result.

Environmental and feasible analysis of recycling steel slag as aggregate treated by silicone resin

Steel slag is the desirable substitution of natural aggregate in asphalt mixture. Nevertheless, the high-water absorption and heavy metal ions pollution are the primary problems of recycling steel slag. This study involved silicone resin to process the steel slag for preventing it from water and improving heavy metal ions leaching problems. The sealing effect of silicon resin on steel slag was also verified by the micro measurement. The results show that the leaching concentrations of all heavy metal ions were generally reduced after treatment of silicone resin. The solid silicone resin formed the airtight membranous on the steel slag surface and effectively improved the heavy metal ions leaching problems. The boundary of elements distribution between steel slag and silicone resin area are obvious, which indicates that the silicone resin effectively and completely seals the steel slag surface. The water absorption rates, adhesion and microstructure of steel slag were also improved by silicone resin. The organic asphalt and silicone exhibit superior adhesion due to the rule of the likes dissolve each other, and it isolates steel slag from water, and reduces the stripping risk of asphalt binder.

Dose evaluation of workers according to operating time and outflow rate in a spent resin treatment facility

Workers’ safety from radiological exposure in a 1 ton/day capacity spent resin treatment facility was evaluated according to the operating times and outflow rate due to process related leakages. The conservative annual dose based on the operating times of the workers exceeded the dose limit by at least 7.38E+01 mSv for close work. The realistic dose range was derived as 1.62E+01 mSv–6.60E+01 mSv. The conservative and realistic annual doses for remote workers were 1.33E+01 mSv and 3.00E+00 mSv respectively, which were less than the dose limit. The MWR was identified as the major contributor to worker exposure within the 1 h period required for removal of radioactive materials. The dose considering both internal and external exposures without APF was derived to be 1.92E+01 mSv for conservative evaluation and 4.00E+00 mSv for realistic evaluation. Furthermore, the dose with APF was derived as 7.27E-01 mSv for conservative evaluation and 1.51E-01 mSv for realistic evaluation. Considering the APF for leakage from all parts, the dose range was derived as 1.25E+00 mSv–2.03E+00 mSv for conservative evaluation and 2.61E-01 mSv–4.23E-01 mSv for realistic evaluation. Hence, it was confirmed that radiological safety was secured in the event of a leakage accident.

Evaluation of dose received by workers while repairing a failed spent resin mixture treatment device

Intermediate-level radioactive waste (ILW) is not subject to legal approval for cave disposal in Korea. To solve this problem, a spent resin treatment device that separates 14C-containing resin from zeolite/activated carbon and desorbs 14C through a microwave device has been developed. In this study, we evaluated the radiological safety of the operators performing repair work in the event of a failure in such a device treating 1 ton of spent resin mixture per day. Based on the safety evaluation results, it is possible to formulate a design plan that can ensure the safety of workers while developing a commercialized device. When each component of the resin treatment device can be repaired from the outside, the maximum and minimum allowable repair times are calculated as 263.2 h and 27.7 h for the 14C-detached resin storage tank and zeolite/activated carbon storage tank, respectively. For at least 6 h per quarter, the worker's annual dose limit remains within 50 mSv/year; further, over 5 years, it remained within 100 mSv. At least 6 h of repair time per quarter is considered, under conservative conditions, to verify the radiological safety of the worker during repair work within that time.

Analysis of Composite Resin Treatment Pattern Changes After the Insurance Coverage

Since January 2019, insurance coverage for caries treatment of permanent teeth using composite resin in children aged 12 and under has started in South Korea. The purpose of this study was to compare the pattern of permanent molar composite resin restoration aged 12 and under before and after the insurance coverage from January 2009 to March 2020 in the Department of Pediatric Dentistry at Kyung Hee University Dental Hospital at Gangdong.<br/>Since the insurance coverage was started in 2019, the frequency of permanent molar composite resin restoration aged 12 and under has increased more than twice. There was a significant change in frequency of resin restoration by shape of cavity comparing before and after the insurance coverage, whereas there was no significant difference in changes by patient age, gender and position of tooth.<br/>As accessibility to the permanent tooth composite resin restoration is increased by the insurance coverage, which shows a fair survival rate, it is expected that it could be able to secure oral health in the early permanent dentition aged 12 and under.

Isolation and Identification of Boswellic Acids by Modern Analytical Techniques

Quality by Design (QbD) is a modern, scientific approach that formalizes product design, automates manual test¬ing, and streamlines troubleshooting. It uses a system¬atic approach to ensure quality by developing a thorough understanding of the compatibility of a finished product to all of the components and processes involved in manufac¬turing that product. Olibanum also known as “Dhup”, Indian Frankincense is an oleo gum resin of Boswellia species. In India it is obtained from Boswellia serrata. Boswellia serrata (Burseraceae) The major use of Boswellia serrata in contemporary medicine is as an anti-arthritic and anti-inflammatory pharmacological agent. The anti-inflammatory properties of the gum resin are attributed to the presence of “boswellic acids” The four major pentacyclic triterpenic acids present in the acidic extract of Boswellia serrata gum resin. β-Boswellic Acid, Acetyl-β-Boswellic Acid, 11-keto-β-Boswellic Acid, Acetyl-11-keto-β-Boswellic Acid. Oleo gum resin was subjected for solubility studies in different solvents. In this 10 commonly available solvents were used for extraction including water. All of them showed same TLC pattern except water. In case of maceration no heat is employed, but the material has to be extracted multiple times with fresh solvent each time. In this method solvent requirement increases. Each time the extract was checked for presence of boswellic acids by TLC to ensure complete extraction. It took 4-5 times repeated extraction for complete extraction of Boswellic acids by maceration. Literature survey reveals that anti-inflammatory activities associated with this resin are completely restricted to presence of Boswellic acids. So focus in experimental work done is placed on isolation of acid fraction of oleo gum resin. As mentioned in the procedures above acid fraction was obtained as white precipitate. This white precipitate was separated, dried and weighed. Amount of acid fraction obtained was determined on weight basis. In the experimental work done isolation of acid fraction was carried out by procedures mentioned in section above. This is common procedure which uses treatment of resin with alkali to convert acid into its salt and then precipitating salt of acid by using mineral acid. Studies were carried out to check variations in amount of acid portion obtained when parameters were altered. Use of 2% KOH followed by dilute hydrochloric acid as mineral acid will be most suitable.

TRANSESTERIFICATION OF VEGETABLE OILS’ TRIGLYCERIDES BY THE HEAD FRACTION OF ETHYL ALCOHOL

The regularities of sunflower, rapeseed and flaxseed oils’ triglycerides transesterification by the head fraction of ethyl alcohol in the presence of various catalysts have been investigated. The cation exchange resin KU-2-8 in H+-form and cation exchange resin KU-2-8 containing an immobilized Cu2+-ions (untreated and treated by 0,1 M sodium hydroxide solution for 90 min and for 7 days) were used as catalyst. It was shown that the all investigated catalysts except the untreated cation exchange resin KU-2-8 containing an immobilized Cu2+-ions allow to achieve of triglycerides conversion over 90 % under the reaction conditions. It was found that the catalyst KU-2-8 containing an immobilized Cu2+-ions treated by 0.1 M sodium hydroxide solution for 90 min shows the highest activity. Also it was found that this catalyst allows to achieve triglyceride conversion all of studied vegetable oils over 99.5% in 180 min of reaction. Simultaneously it was found that the highest rate of transesterification reaction in its presence is observed. The influence of these catalysts on the esterification reaction of free fatty acids, present in vegetable oils, by ethyl alcohol, present in the head fraction, was studied. It was established that the influence of the investigated catalysts on the esterification reaction is different. It was shown that cation exchange resin KU-2-8 containing an immobilized Cu2+-ions treated by 0.1 M sodium hydroxide solution for 90 min catalyzes the esterification reaction of free fatty acids of all investigated oils. Their conversion is from 21.6 % (in sunflower oil) up to 74.1 % (in rapeseed oil). At the same time, it was found that long-term treatment of cation exchange resin KU-2-8 containing an immobilized Cu2+-ions by sodium hydroxide solution leads to a sharp decrease or loss of catalyst activity in the esterification reaction of free fatty acids by ethyl alcohol. It was shown that the use of this catalyst for the transesterification of rapeseed and sunflower oils’ triglycerides even increases the acid number of the reaction mixture, namely to the partial hydrolysis of triglycerides. The obtained results show that the short-term treatment the cation exchange resin KU-2-8 containing an immobilized Cu2+-ions by 0.1 M alkali solution is one of the ways that allow to increase its catalytic activity in the transesterification process of vegetable oils by head fraction of ethyl alcohol. It is assumed that such treatment affects the catalytic activity of Cu2+-ions due to changes in the electron density on the catalyst cation caused the coordination of part of the OH–-anions. The long-term treatment of the cation exchange resin containing an immobilized Cu2+-ions by alkali solution causes a maximum saturation of the cation coordination sphere. This obviously creates steric problem of a reagents access to the catalyst and reduces the catalytic activity cation exchange resin.

Hyperkalaemia management and related costs in chronic kidney disease patients with comorbidities in Spain.

BackgroundHyperkalaemia (HK) is a common electrolyte disorder in patients with chronic kidney disease (CKD) and/or treated with renin–angiotensin–aldosterone system inhibitors (RAASis). The aim of this study is to determine the severity, current management and cost of chronic HK.MethodsWe performed a retrospective cohort study of patients with chronic HK and CKD, heart failure or diabetes mellitus between 2011 and 2018. The study follow-up was 36 months.ResultsA total of 1499 patients with chronic HK were analysed: 66.2% presented with mild HK, 23.4% with moderate HK and 10.4% with severe HK. The severity was associated with CKD stage. Most patients (70.4%) were on RAASi therapies, which were frequently discontinued (discontinuation rate was 39.8, 49.8 and 51.8% in mild, moderate and severe HK, respectively). This RAASi discontinuation was similar with or without resin prescription. Overall, ion-exchange resins were prescribed to 42.5% of patients with HK and prescriptions were related to the severity of HK, being 90% for severe HK. Adherence to resin treatment was very low (36.8% in the first year and 17.5% in the third year) and potassium remained elevated in most patients with severe HK. The annual healthcare cost per patient with HK was €5929, reaching €12 705 in severe HK. Costs related to HK represent 31.9% of the annual cost per HK patient and 58.8% of the specialized care cost.ConclusionsHK was usually managed by RAASi discontinuation and ion-exchange resin treatment. Most patients with HK were non-adherent to resins and those with severe HK remained with high potassium levels, despite bearing elevated healthcare expenditures.

Evaluation of water related properties of birch wood products modified with different molecular weight phenol-formaldehyde oligomers

Abstract This study investigated the effect of phenol-formaldehyde (PF) resin treatment on the dimensional stability of birch solid wood and plywood. Therefore, three different low molecular weight PF resins with average molecular weights (M w ) of 292, 528, and 884 g/mol were synthesized and used for silver birch (Betula pendula) solid wood (20 × 20 × 20 mm3) and veneer (100 × 100 × 1.4 and 300 × 300 × 1.4 mm3) impregnation to produce plywood. The weight percent gain (WPG) and bulking after curing of resin treated wood specimens were determined. The leaching was performed to evaluate the PF resin fixation stability. All tested resins at all concentrations were similarly fixed in wood blocks after the leaching (1.5–2.0% WPG loss). The dimensional stability of birch wood after treatment with all tested PF resins was significantly improved. The anti-swelling efficiency (ASE) of birch wood blocks treated with PF resins after seven water soaking-drying cycles was in the range of 39–53%, 46–65% and 49–65% using 10, 15 and 20% solution concentrations, respectively. Whereas, the ASE of plywood obtained from veneers treated with 10% of PF solution was improved by 6–20%. The equilibrium moisture content (EMC) and volumetric swelling (VS) of PF treated plywood at 98% of relative humidity (RH) decreased significantly. All PF resin treated plywood surfaces were more hydrophobic compared to untreated plywood.