Category: 52829-07-9

Tirri, Teija published the artcileSulfenamides in synergistic combination with halogen free flame retardants in polypropylene, Quality Control of 52829-07-9, the main research area is sulfenamide halogen free flame retardant polypropylene thermal fireproofing.

Sulfenamide based radical generators that contain a nitrogen-sulfur (N-S) core, can alone provide flame retardancy in polypropylene (PP), polyethylene and polystyrene, as we have earlier demonstrated. Herein, sulfenamides potential as synergists with conventional halogen free flame retardants has been explored. Thus, five different sulfenamides were individually combined with selected eco-friendly, phosphorus based flame retardants or aluminum trihydroxide (ATH), and their effect on polypropylene flammability was assessed by limiting oxygen index (LOI), vertical flammability (UL 94 V) and cone calorimeter tests. Thermogravimetric anal. (TGA) and NMR (NMR) studies were carried out to detect changes in thermal behavior when such two component FR systems were mixed together at different ratios. TGA-FTIR (thermogravimetric anal.-Fourier transform IR spectroscopy) was used to investigate the differences in decomposition products of non-flame retarded vs. flame retarded PP. Strong synergistic effects were observed, and the UL 94 V-0 rating was reached for PP with a total FR loading of 10 wt% using 8 wt% of phosphonate ester AFLAMMITPCO 900 together with 2 wt% of sulfenamide flame retardant. In a ternary mixture of an addnl. phosphazene additive (SPB-100), the needed total concentration for V-0 rating was further reduced to 9 wt%. In addition, the combination of 4 wt% of aluminum hypophosphite (AHP) with 0.5 wt% of sulfenamide offered a unique halogen free solution for achieving UL 94 V-2 rating in PP. Cone calorimeter studies of an ammonium polyphosphate-pentaerythritol based intumescent system in combination with 0.5 wt% of sulfenamide also showed encouraging results. The char stability was enhanced, the peak of heat release rate (HRR), CO and CO2 production and total smoke generation were all reduced compared to the reference sample without sulfenamide.

Polymer Degradation and Stability published new progress about Chars. 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

van Iperen, Jolanda published the artcileCrystalline Deposits in New Display Cases at the Rijksmuseum: Characterisation and Origin, Application of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is raman spectroscopy carboxylic acid.

An unusual phenomenon occurred in new display cases at the Rijksmuseum four months after their installation in Apr. 2013. White deposits were visible on glass windows, silicone door gaskets, black structural adhesive seals, and on works of art. The works of art most affected by these deposits were bronze sculptures, wooden and waxed objects, tempera, and oil paintings. It was found that TMP-ol, which is part of the UV-light stabilizer Tinuvin-770, emitted from the structural adhesive Terostat-9220. Terostat-9220 was used in large quantities in the display cases to adhere glass windows to metal parts. The carboxylic acids derived from both construction materials used to build the cases and from conservation materials present on the exhibited works of art. The carboxylic acids involved were 2,4-dichlorobenzoic acid, formic acid, methacrylic acid, palmitic acid, and an unknown carboxylic acid, resp. emitted from peroxide-cured silicone gaskets, panels of medium-d. fiberboard (MDF), UV-adhesive, beeswax containing products, and from an unknown acidic conservation product or binding medium. The identification of the crystalline deposits was supported by their syntheses in the laboratory Since 2013, similar deposits have been observed in a number of museum collections worldwide. A treatment for preventing further growth of the deposits was developed and applied in the Rijksmuseum showcases.

Studies in Conservation published new progress about Beeswax. 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 of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Zhang, Chaohong published the artcileTop-down strategy identifying molecular phase stabilizers to overcome microstructure instabilities in organic solar cells, Safety of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is organic solar cell microstructure instability mol phase stabilizer.

The operational stability of organic solar cells (OSCs) is the essential barrier to commercialization. Compared to thermally-induced degradation, photo-stability of OSCs is far away from being resolved. Here, we demonstrate that the thermal- and photo-degradation of metastable bulk-heterojunction OSCs are governed by the same mechanism. Understanding the fundamental principles behind this mechanism is of significant importance to fully address the instability issues. Structural incompatibilities between the donor and acceptor mols. are identified as the main origin of the instability. Further, we introduce a top-down approach mainly based on their melting temperature and interaction parameters to rationally screen mol. phase stabilizers from a database with more than 10 000 small mols. Eventually, five chems. were selected to validate our concept and tested in unstable organic solar cells. 1,4-Piperazine, which possesses a high m.p., good miscibility with polymers and the capability of forming inter-mol. hydrogen bonding, can indeed stabilize the mixed amorphous phases, leading to significantly improved stability of otherwise metas table OSCs.

Energy & Environmental Science published new progress about Annealing. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Safety of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Twigg, Christopher published the artcilePeroxide-initiated chemical modification of polyolefins: In search of a latent antioxidant, Formula: C28H52N2O4, the main research area is peroxide initiated polyolefin antioxidant.

The ability of piperidine-based compounds to confer oxidative stability to polyolefin thermosets without compromising the yields of peroxide-initiated crosslinking and monomer grafting is demonstrated. Unlike phenolic, nitroxyl and phosphite antioxidants that lower the concentration of macroradical intermediates that support polyolefin modifications, additives based upon 2,2,6,6-tetramethylpiperidine (TEMPH) are shown to have little to no effect on the extent of LLDPE crosslinking or the conversion of vinyltriethoxysilane (VTEOS) to grafted hydrocarbon adducts. Notwithstanding this lack of interference in radical-mediated polymer modification, this class of hindered light stabilizer (HAS) compounds are shown to limit the extent of radical oxidation of linear low-d. polyethylene (LLDPE) in an accelerated aging test. The origins of this paradox are discussed in terms of the current state of knowledge regarding HAS activation. The latent antioxidant concept is extended to an alternate approach, wherein 4-acryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl (AOTEMPO) is used as an alkyl radical scavenger bearing an oligomerizable functional group. When added at a fraction of the peroxide loading used to produce an LLDPE thermoset, ATEMPO is shown to provide a predictable induction delay without impacting ultimate crosslink d., and produces polymer-bound alkoxyamine functionality that stabilizes the product against oxidation

Polymer published new progress about Antioxidants. 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

Zhang, Xi published the artcileDielectric Properties of Biaxially Oriented Polypropylene Nanocomposites Prepared Based on Reactor Granule Technology, COA of Formula: C28H52N2O4, the main research area is dielec biaxially oriented polypropylene nanocomposite reactor granule technol.

The addition of inorganic nanoparticles is one of the most widely studied strategies to improve dielec. properties of thin film capacitors, but its application to biaxially oriented polypropylene (BOPP) has rarely been reported due to the difficulty of stretching without break. Here, we have investigated dielec. properties of BOPP/TiO2 nanocomposites prepared by a reactor granule technol., in which precursors impregnated in the pores of PP reactor granule are converted into highly dispersed oxide nanoparticles during melt mixing. The permittivity of the nanocomposites was greatly enhanced beyond classical mixing rules by the addition of a small amount of TiO2 nanoparticles (1-5 wt %), and the enhancement was very sensitive to the stretching ratio. A critical role of the interphase region was suggested. The AC breakdown voltage (BDV) of the BOPP/TiO2 nanocomposites decreased sharply with respect to the amount of TiO2 added. The detailed anal. suggested the roughening of the film surface around the nanoparticles due to stretching as the main cause of the BDV reduction

ACS Applied Electronic Materials published new progress about Antioxidants. 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

Kot, David published the artcilePorous graphite as stationary phase for the chromatographic separation of polymer additives – determination of adsorption capability by Raman spectroscopy and physisorption, Related Products of piperidines, the main research area is porous graphite stationary phase chromatog separation polymer additive antioxidant; adsorption capability Raman spectroscopy physisorption polyolefin light stabilizer; Adsorption potential distributions; Brunauer emmett teller (BET) method; HPLC of polymer additives; Polyolefins; Porous graphitic carbon; Raman spectroscopy.

Additives are added to polymers in small concentration to achieve desired application properties widely used to tailor the properties. The rapid diversification of their mol. structures, with often only minute differences, necessitates the development of adequate chromatog. techniques. While modified silica so far is the workhorse as stationary phase we have probed the potential of porous graphitic carbon (HypercarbTM) for this purpose. The results show that the multitude of physicochem. interactions between analyte mols. and the graphitic surface enables separations of polyolefin stabilizers with unprecedented selectivity. To support the chromatog. results the adsorption capability of HypercarbTM for selected antioxidants and UV absorbers was determined by Raman spectroscopy and argon physisorption measurements. The shift of the Graphite-band in the Raman spectra of HypercarbTM upon infusion with additives correlates with the changes in the Adsorption Potential Distributions. The results of argon physisorption measurements go hand in hand with the chronol. of desorption of the additives in liquid chromatog. experiments The elution sequence can be explained by van der Waals or London forces, π-π-interactions and electron lone pair donor-acceptor interactions between the graphite surface and analyte functional groups.

Journal of Chromatography A published new progress about Antioxidants. 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

Gajdosova, Veronika published the artcilePro-oxidant activity of biocompatible catechin stabilizer during photooxidation of polyolefins, HPLC of Formula: 52829-07-9, the main research area is oxidative biocompatible catechin stabilizer photooxidation polyolefin.

Polymer plaques made of high-d. polyethylene (HDPE) or cycloolefin copolymer (COC) were stabilized with natural phenolic stabilizer (+)-catechin (CAT) and aged using accelerated weathering technique (WOM; accelerated photooxidation). The efficiency of the phenolic stabilizer was compared with a well-established hindered amine stabilizer (HAS) Tinuvin770 (Tin770). In pursuit of the stabilization and identification of short-living radicals generated in the process of photooxidation of the polymers, a spin trapping agent 2,4,6-tri-tert-butylnitrosobenzene (TTBNB) was added to selected samples. Profiles of oxidation products and crystallinity inside the HDPE plaques were determined by IR microspectroscopy, oxidation products in COC copolymers were identified using ATR spectroscopy, concentration profiles of radicals generated inside polymer plaques during WOM exposure were determined by ESRI, the changes of local mech. properties at the surface of polymer plaques were characterized using microindentation hardness testing (MHI), and the surface morphol. changes were studied by light and/or SEM. All methods are in accordance with the conclusion that the natural phenolic stabilizer CAT exhibited pro-oxidant activity during accelerated photooxidation of both polymers, i.e. higher concentration of oxidation products, bigger changes of local mech. properties and/or more microcracks on the exposed surfaces in comparison with non-stabilized systems and systems stabilized with Tin770.

Polymer Degradation and Stability published new progress about Antioxidants. 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

Nakatani, Hisayuki published the artcileNovel Recycling System of Polystyrene Water Debris with Polymer Photocatalyst and Thermal Treatment, COA of Formula: C28H52N2O4, the main research area is polystyrene hindered amine light stabilizer polymer photocatalyst thermal treatment.

A poly(styrene-block-acrylic acid) containing TiO2 gel (PS-b-PAA/TiO2) polymer photocatalyst had the same d. as PS and could provoke photocatalytic activity to PS particles in water. It showed photocatalytic activity to a PS containing a N-H type hindered amine light stabilizer (PS/LA-77) in water under the UV irradiation The mol. weight decrease was ca. 10%, showing that a weaker light source and different kind of hindered amine light stabilizer (HALS) should be employed. The phthalocyanine modified photocatalyst had the activity under visible light irradiation In addition, a N-OR type HALS (LA-81) loading worked as radical scavenger, showing that the PS autoxidation was certainly controlled. After the 144 h irradiation, the mol. weight was drastically decreased with the increases of heating temperature and time. When the heat treatment was performed by the enclosed sample with the aluminum foil, the mol. weight change behavior was considerably different between the PS and PS/LA-81. The difference was due to the chain scission mechanism. The intra-alkyl radical production in PS chain allowed controlling mol. weight by the heat treatment.

Journal of Polymers and the Environment published new progress about Autoxidation. 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

Rus, Anika Zafiah M. published the artcileDeterioration rate of renewable polyurethanes composites prior to ultra violet irradiation exposure, Application of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is polyurethane composite preparation UV irradiation deterioration.

Polyurethanes (PU’s) made from renewable and sustainable materials are one of the most important groups of polymers because of their versatility with wide range of grades, densities and stiffness. In this project, polymers based on renewable materials such as rapeseed (RS) and sunflower oil (SF) were synthesized and cross-linked to form polyurethanes. The effect of prolonged exposure up to 1000 h upon UVB light, in general promotes photodegradation for both RS and SF-based polyurethanes, both neat and also composites loaded with TiO2. The addition of 10% Degussa P25 TiO2 pigment, gives the greater degradation while PUs loaded with 5% Kronos 2220 show the slowest rates of degradation due to the effect of the coating of this pigment. The photostabilizer Tinuvin 770 offers high protection from UVB, thus lead the combination of Tinuvin 770 with Degussa P25 promotes the highest protection from UVB exposure. Moreover, addition of Tinuvin 770 at the stage of preparation of the PUs also greatly reduced the undesirable yellow coloration prevalent during PU synthesis.

Composites, Part B: Engineering published new progress about Absorption. 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 of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Lin, Yi-Li published the artcileUsing in situ modification to enhance organic fouling resistance and rejection of pharmaceutical and personal care products in a thin-film composite nanofiltration membrane, HPLC of Formula: 52829-07-9, the main research area is NF90 hydroxyethyl sulfopropyl methacrylate potassium personal care product antifouling; Adsorption; Antifouling; In situ modification; Modified Hermia model; Nanofiltration; Pharmaceutical and personal care products (PPCPs); Radical graft polymerization.

A com. available nanofiltration membrane, NF90, was modified using an in situ concentration polarization-enhanced radical graft polymerization method to improve the organic fouling resistance as well as the removal of pharmaceutical and personal care products (PPCPs), including ibuprofen (IBU), carbamazepine, sulfadiazine, sulfamethoxazole, sulfamethazine, and triclosan (TRI). 3-Sulfopropyl methacrylate potassium salt (SPM) and 2-hydroxyethyl methacrylate (HEMA) were used in various dosages for surface modification, and the extent of membrane modifications was quantified based on the degree of grafting. The modified NF90 exhibited a 15-40% lower flux during humic acid (HA) fouling and 25% greater NaCl rejection compared with the virgin membrane. PPCP rejection in the modified NF90 membranes before and after HA fouling was 20-45% and 5-20% greater, resp., compared with that of the virgin membrane. Both SPM and HEMA increased the hydrophilicity of NF90 by decreasing contact angles. SEM revealed lower amounts of foulants on the modified NF90 than on the virgin membrane. The main fouling mechanism for virgin NF90 was gel layer formation and those for modified NF90 were complete and intermediate blocking. Therefore, the modification of NF90 was effective for controlling organic fouling and strongly rejecting PPCPs.

Environmental Science and Pollution Research published new progress about Adsorption. 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