Tag: M.W:400-500

Lee, Juhyeon published the artcileSelective decomposition of hexabromocyclododecane in polystyrene and recyclability improvement of its polymeric component, Recommanded Product: Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is recycled polystyrene hexabromocyclododecane selective decomposition thermal mech property.

Selective flame retardant decomposition and polymer recycling in a polystyrene (PS) material containing hexabromocyclododecane (HBCD) were studied using a paint-type copper phthalocyanine modified TiO2 (CuPcTiO2)/polyethylene oxide (PEO) photocatalyst system with three kinds of hindered amine light stabilizer (HALS) loadings. They were performed using visible light irradiation and addnl. thermal hybrid treatments. Mobility of the HALS with lightest weight was highest and caused the bleeding from the matrix during the irradiation treatment, leading to a lower decomposition ratio and larger changes of dynamic mech. properties of the recycled PS. On the other hand, the higher mol. weight HALS loadings provided the higher ratios and blocked the changes. In particular, the properties in the HALS loading with a dormant (TEMPO) bond were hardly changed by such hybrid treatment. The py-GC/MS spectra of the extraction residue showed that the HALS adequately worked depending on the treatment situation as radical scavenger and initiator. The tensile strength and strain at break values of the recycled PS kept 90% of the pristine one. In addition, there were no significant differences between the SEM images. The results showed that it had sufficient performance to be used as the post-consumer material.

Polymer Degradation and Stability published new progress about Elongation at break. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Recommanded Product: Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Srirodpai, Onruthai published the artcilePreparation, characterizations and oxidation stability of polyethylene coated nanocrystalline VO2 particles and the thermo-chromic performance of EVA/VO2@PE composite film, Quality Control of 52829-07-9, the main research area is ethylene vinyl acetate copolymer vanadium dioxide polyethylene film.

In this study, an alternative approach is presented for developing thermo-chromic film, based on ethylene vinyl acetate copolymer (EVA) and vanadium dioxide (VO2) composite, with enhanced oxidation stability and compatibility. The neat monoclinic nanocrystalline VO2 particles were firstly prepared via a hydrothermal process, using citric acid as a reducing agent. After that, the synthesized VO2 particles were characterized, prior to mixing with maleic anhydride grafted PE. The crystalline structure, morphol. and thermochromic performance of the polyethylene coated vanadium dioxide (VO2@PE) particles were then verified by SEM, TEM, DSC, XRD, FTIR techniques. After coating, a better oxidation stability of the VO2 particles was noted while the thermo-chromic performance of the VO2@PE was also maintained. After mixing with EVA, the percentage strain and tensile toughness of the VO2@PE based EVA films was the highest, followed by those of the uncoated VO2-based EVA films and the neat EVA, resp. The VO2@PE-based films also maintained the thermochromic behavior of the monoclinic VO2. The above improvements were achieved at the expense of percentages of visible light transmittance and gel content of the EVA. This is the first report of the EVA/VO2-based thermo-chromic film, which is tougher and more stable toward oxidation than the prior state of the art. This composite film has the potential to be used as a kind of a specialty lamination material for smart windows and energy efficiency in buildings.

Journal of Nanoscience and Nanotechnology published new progress about Elongation at break. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Quality Control of 52829-07-9.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Rathinamoorthy, R. published the artcileDisposable tri-layer masks and microfiber pollution – An experimental analysis on dry and wet state emission, Synthetic Route of 52829-07-9, the main research area is disposable trilayer mask microfiber pollution dry wet emission; Freshwater; Microfiber shedding; Polypropylene; Rubbing; Seawater; Tri-layer mask.

The use of masks as a personal protective material is the new normal in the post-pandemic. The higher use of masks triggers immediate disposal of synthetic textile fibers leading to environmental pollution. This research is aimed to analyze the level of mask-related pollution and its impact on microfiber release. Microfiber emission characteristics of the tri-layer nonwoven mask (Polypropylene-based disposable mask) are analyzed in the dry and wet stages. The individual layers of the mask and the entire mask are evaluated by subjecting them to static immersion and mech. agitation against freshwater and seawater in the wet stage. The results of the study showed a higher microfiber shedding at dry state (14,031.97-177,601.58 fibers/mask) than the wet state (2557.65-22,525.89 fibers/mask). The increased fuzz formation in the dry state than the wet state is noted as the main reason. In the case of wet state, when the freshwater and seawater are compared, both in a static and agitated state, seawater degraded the mask highly (3358.03-27,348.9 fibers/mask) than the freshwater (1757.26-17,702.86 fibers/mask). Higher salinity and d. of the seawater were noted as influencing parameters over the freshwater. When the results of naturally weathered masks are compared with the new mask, weathered masks released significantly (p < 0.05) higher amount of fibers at the evaluation stages. Similar to the new masks, the weathered masks also showed a higher amount of shedding in the dry state and presence of seawater. When the individual layers of the disposable masks were evaluated, at dry and wet states, all the layers showed a similar shedding (no significant difference between individual layers) in the case of a new mask. Whereas, after weathering, a significant amount of higher shedding (p < 0.05) is noted in the middle layer of the mask followed by the outer and inner layer. The difference in fiber composition is noted as the main reason for the strength difference of the nonwoven structure. Statistical anal. confirmed the significant impact of the natural weathering process and seawater on the microfiber shedding. Science of the Total Environment published new progress about Environmental pollution. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Synthetic Route of 52829-07-9.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Song, Wanchao published the artcileNanofiltration desalination of reverse osmosis concentrate pretreated by advanced oxidation with ultrafiltration: Response surface optimization and exploration of membrane fouling, Formula: C28H52N2O4, the main research area is nanofiltration desalination reverse osmosis advanced oxidation ultrafiltration membrane fouling.

Reverse osmosis (RO) technique has been widely used in the advanced treatment of industrial water and wastewater. However, this process generates a large amount of reverse osmosis concentrate (ROC) which contain high salinity and organic contaminants, and therefore pose serious environmental problems. This study explored the potential of advanced oxidation processes-ultrafiltration (AOPs-UF) pretreatment system and nanofiltration (NF90, Dow Chems.) membrane system for ROC desalination. Under the optimal conditions, 78% of COD and 81% of UV254 pollutants were removed by using advanced oxidation processes with ultrafiltration pretreatment technol. Box-Behnken design (BBD) results showed that the maximum total soluble salts rejection of 97.75% was obtained under the optimized conditions of nanofiltration membrane (the 1.18 MPa operating pressure, 6.79°C feed temperature, 64.33 min filtration time). A combined membrane cleaning method was finally determined via surface morphol. characterization by the comparison of scanning electron microscope (SEM), X-ray energy dispersive anal. (EDS) and Fourier transform IR (FTIR) technique anal. The results confirmed the possibility of advanced oxidation coupled membrane treatment process to treat ROC and realize its reuse. Moreover, by evaluating the benefit calculation, it provides insights for the treatment of industrial wastewater.

Journal of Environmental Chemical Engineering published new progress about Chemical oxygen demand. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Formula: C28H52N2O4.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Desai, Umang published the artcileA comparison of evolution of adhesion mechanisms and strength post damp-heat aging for a range of VA content in EVA encapsulant with photovoltaic backsheet, Application In Synthesis of 52829-07-9, the main research area is ethylene vinyl acetate film fabrication adhesion strength.

Ethylene vinyl acetate (EVA) is an effective encapsulant to adhere various layers in the photovoltaic (PV) module. In this study, we have fabricated EVA films containing different vinyl acetate (VA) content (18%, 24%, 33% and 40%) and laminated between two layers of backsheet (BS). These laminates have been subjected to damp-heat (DH) ageing at 85OC and 85% relative humidity (RH) for 1000 h to evaluate the change in adhesion strength at EVA/BS interface using the T-peel test. The adhesion strength for EVA containing 18% VA content has been found to improve but it deteriorates for EVA with 33 and 40% VA content after ageing. However, adhesion strength for EVA containing 24% VA content is found unaffected after ageing. The degree of crosslinking and VA content have been determined through gel content measurement and thermo-gravimetric anal. (TGA) resp. The degree of crosslinking and VA content increases significantly in EVA18 but decreases in EVA40 due to DH ageing. The chem. changes have been examined by the Fourier transform IR spectroscopy (FTIR) and the XPS. The failure mode (cohesive or delamination) at the interface and its correlation with the adhesion strength has been explored using XPS. The failure mode at the EVA18/BS interface alters from delamination type in pristine condition to the cohesive type due to DH ageing. However, the failure mode for EVA24 and EVA40 is found to be cohesive in both the pristine and aged condition.

Solar Energy published new progress about Adhesion, physical, interfacial. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Application In Synthesis of 52829-07-9.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Slouf, Miroslav published the artcileProoxidant activity of phenolic stabilizers in polyolefins during accelerated photooxidation, Recommanded Product: Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is prooxidant phenolic stabilizer polyolefin accelerated photooxidation.

Polymer plaques made of high d. polyethylene (HDPE) and of two types of cycloolefin copolymer (COC) differing in glass transition temperature, were stabilized with 0.2 or 1.0 weight % of natural (α-tocopherol) or synthetic (Irganox 1010) phenolic stabilizer or hindered amine stabilizer (Tinuvin 770) and aged using accelerated weathering technique (WOM). The efficiency of the phenolic stabilizers was compared among themselves and with well-established Tinuvin770. Concentration profiles of radicals generated inside polymer plaques during WOM exposure were determined by ESRI, profiles of oxidation products and crystallinity inside the HDPE plaques were determined by IR microspectroscopy, oxidation products in COC copolymers were identified using ATR, the changes of local mech. properties of the polymer plaques were characterized using microindentation hardness testing, and their morphol. was studied by light and/or SEM. All the techniques evidenced high stability of neat COC against photooxidation processes, whereas neat HDPE exhibited fast photooxidation of the surface layers. Tinuvin770 was found to provide long term protection to both HDPE and COC against photodegradation In contrast, the same polymers stabilized with the natural phenolic antioxidant α-tocopherol (the most active component of vitamin E) or synthetic phenolic antioxidant Irganox1010 exhibited an increase in the surface oxidation in comparison with the neat polymers during WOM exposure, proving prooxidant activity of phenolic stabilizers during WOM exposure in all polymers studied. The prooxidant activity α-tocopherol was stronger in comparison with Irganox1010. We conclude that neither of the two phenolic stabilizers was able to provide long term protection of the investigated polymers against photooxidation

Polymer Degradation and Stability published new progress about Aging of materials, accelerated. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Recommanded Product: Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Christmann, Julien published the artcilePhotostabilization of polyethylene by a hindered amine light stabilizer in blooming conditions and impact of MDO processing, HPLC of Formula: 52829-07-9, the main research area is polyethylene light stabilizer MDO processing photostabilization property.

The effect of machine direction orientation (MDO) processing on the photostabilization of LLDPE samples containing Tinuvin 770 was studied. The amount of Tinuvin 770 in the processed samples was deliberately chosen at a level higher than the reported solubility at ambient temperature for two main reasons: the first reason was to assess the equilibrium between the soluble and nonsol. forms of this additive and the impact of the MDO process, and the second was to demonstrate the role of a higher temperature in accelerated artificial photoaging on the protective role played by the nonsol. part. The results reported in this article show that at room temperature, a nonnegligible amount of Tinuvin 770 precipitates at the surface, which is commonly termed blooming. However, the additive that bloomed at the surface can be dissolved within the polymer with increasing temperature, which is the case in the conditions of accelerated artificial photoaging but not the case of natural outdoor weathering. Such phys. phenomena are responsible for a possible bias brought by temperature during accelerated photoaging, which can affect aging tests. This questions the representativeness of accelerated aging at higher temperatures for polymers containing a blooming stabilizer.

Polymer Degradation and Stability published new progress about Aging of materials, accelerated. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, HPLC of Formula: 52829-07-9.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Chang, Chia-Wei published the artcileThe effects of adding different HALS on the curing process, film properties and lightfastness of refined oriental lacquer, Related Products of piperidines, the main research area is hindered amine stabilizer curing lightfastness oriental lacquer film property; hindered amine light stabilizers; laccase-catalyzed reaction; oriental lacquer; oxidative polymerization.

Oriental lacquer is a natural polymeric coating with a satiny texture and excellent characteristics, such as chem. resistance and durability. However, the poor lightfastness resulted in the natural aromatic structures of the urushiol structures limited its suitability for outdoor application. This study aimed at the improvement of the lightfastness by adding the different hindered amine light stabilizers (HALS) with 2 phr addition as well as the effects on the coating and film property of the refined oriental lacquers (RL). The Cryptomeria japonica plate, glass sheets, and the other substrates were used for finishing. The results showed that the lightfastness of RL film was obviously improved by adding 2 phr HALS of Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (H90) containing -NH group and Bis (1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-di-Me ethyl) -4-hydroxyphenyl] methyl] butylmalonate (H60) containing -NCH3 groups. The HALS additions increased the pH value of RL and improved the activities of laccase-catalyzed reaction. Meanwhile, the oxidative polymerization of the side chains of RL was inhibited, caused by a radical scavenging ability of HALS. The changes in the drying process affected not only the curing time, but also the film properties. Among the 2 phr additions of different HALS, the film containing H90 had the best lightfastness. Meanwhile, it kept the most similar properties with RL and shortened the drying time of RL, and it was selected as the best HALS addition under 2 phr in this study.

Polymers (Basel, Switzerland) published new progress about Abrasion-resistant coating materials. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Related Products of piperidines.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Desai, Umang published the artcileEnhancement of resistance against damp heat aging through compositional change in photovoltaic encapsulant poly (ethylene-co-vinyl acetate), Application In Synthesis of 52829-07-9, the main research area is polyethylene vinyl acetate copolymer resistance damp heat photovoltaic encapsulant.

The most common encapsulant used in the photovoltaic (PV) modules is poly (ethylene-co-vinyl acetate) (PEVA). The characteristics of PEVA can be varied by modulating its vinyl acetate (VA) content. According to the general consensus within the PV industry, PEVA as an encapsulant should have VA content between 28 and 33%. Degradation of PEVA films due to environmental stressors like humidity, temperature and solar radiation in the field aged modules is not uncommon. Moreover, degradation of PEVA encapsulant implies a concomitant loss in the elec. performance of the PV modules. VA content modulation especially outside the most commonly used and accepted range has been tried in this study to improve the damp heat aging resistance of PEVA films. PEVA films containing 18, 24, 33, and 40% VA content with the necessary additives have been fabricated and cured at 150°C under vacuum and subsequently subjected to accelerated damp-heat (85°C and 85% RH) aging according to IEC 61215 standard for 1000 and 2000 h. Tensile strength, thermal stability and degree of crosslinking have been found to be greater for PEVA containing lower VA content (18 and 24%) and diminished for PEVA with higher VA content (33 and 40%) due to DH aging. However, inadequate % transmittance and relatively high stiffness after 2000 h of DH aging discourages PEVA18 as an encapsulant. Moreover, PEVAs with higher VA content (33 and 40%) have been degraded significantly after 2000 h of DH aging resulting in significant loss in transmittance and mech. integrity. Therefore, the results of this investigation encourage the PV industry to reduce the VA content in PEVA down to 24% for better encapsulation response against DH aging.

Solar Energy published new progress about Differential scanning calorimetry. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Application In Synthesis of 52829-07-9.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Blazquez-Blazquez, Enrique published the artcileIdentification of Additives in Polypropylene and Their Degradation under Solar Exposure Studied by Gas Chromatography-Mass Spectrometry, COA of Formula: C28H52N2O4, the main research area is polypropylene additive solar gas chromatog.

Additives are absolutely essential in the development of com. polymeric materials. Accordingly, an exhaustive control of composition and evolution in these additives over time is necessary to validate their performance and safety during their shelf life and, consequently, their ultimate applications. Gas chromatog. coupled with mass spectrometry, GC-MS, is described in the present work to identify and analyze the content of a wide variety of additives, commonly used in industrial polymeric materials. First, the identification under the present exptl. protocol of additives with a relatively high mol. weight (Irganox 1330 and Irganox 1010) has been successfully attained. Second, the evolution under solar exposure over time has been analyzed by GC-MS for 11 additives and derived substances have been identified in a com. polypropylene sample, estimating the corresponding depletion times. In addition, the resultant increase of carbonyl groups in the polymeric macrochains along the photo-oxidation has been also determined by IR spectroscopy. Therefore, GC-MS is found to be a reliable tool for the anal. of the evolution of commonly used polymer additives under specific degradation conditions, which can be very useful in the formulation of improved future additivations.

ACS Omega published new progress about Environmental polymer degradation. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, COA of Formula: C28H52N2O4.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem