Category: 1761-71-3

Sridhar, Arun Srikanth published the artcileEffect of stoichiometry on crosslinked epoxy resin characteristics: structural heterogeneities, topological defects, properties, free volume and segmental mobility, Category: quinuclidine, the publication is Soft Matter (2022), 18(12), 2354-2372, database is CAplus and MEDLINE.

Exptl. studies have shown that changes in stoichiometry (R, ratio of amine groups to epoxy groups) cause considerable variations in the properties of epoxy-amine systems. Rationales based on free volume concepts have been routinely used to address these variations in properties but have hardly been satisfactorily substantiated. Many of these rationales remain as unverified conjectures to date. Substantiating these rationales will certainly bolster our understanding of the structure-stoichiometry-property relationship, but is difficult, due to inherent challenges involved in unambiguously characterizing the structural heterogeneities induced by changes in stoichiometry (structural heterogeneities include compositional distribution in the functionality of monomers, non-uniform dispersion of elastic chains and topol. defects). The aim of the present work is to gain mol.-level insights into this relationship and to verify the rationales that rely on free volume concepts used for addressing the variations in properties with stoichiometry, with the help of all-atom mol. dynamics (MD) simulations. Five epoxy-amine systems with varying R ranging from 0.4 to 3, including the stoichiometric system (R = 1), were considered for these purposes. The properties of interest namely d., glass transition temperature (T_g) and thermal expansion coefficient in the rubbery state (α_rl) of these systems were predicted. The local structure, fractional free volume and segmental mobility of these systems were then subsequently characterized as a function of stoichiometry and the results were analyzed in detail. The role played by defects in properties and fractional free volume was then investigated. The results revealed significant insights into the compositional distribution of monomers with different functionalities as well as offered insights into the dispersion state and mobility of dangling chains, sols and elastic chains in the systems. Further, strong correlations were found between defect composition, fractional free volume at an elevated temperature (600 K) and thermomech. properties (T_g and α_rl) and it was established that the key mechanism underlying these correlations was the plasticization caused by defects. Anal. based on the rule of mixture models showed that these correlations were found to be in good agreement with the interpretations based on free volume concepts. The results also revealed a strong neg. correlation between fractional free volume at room temperature and defect composition, a phenomenon typically associated with the antiplasticization effect.

Soft Matter published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C2H2N4O2, Category: quinuclidine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Liu, Xin published the artcileHydrogenative depolymerization of silicon-modified polyureas, Recommanded Product: 4,4-Diaminodicyclohexyl methane, the publication is Chemical Communications (Cambridge, United Kingdom) (2022), 58(35), 5415-5418, database is CAplus and MEDLINE.

Silicon-modified polyureas were depolymerized by hydrogenation in the presence of Ru and Mn catalysts. Yields of up to 84% of the aliphatic diamine and 81% of silicon-containing diamine were achieved with a com. available PNP-Ru catalyst.

Chemical Communications (Cambridge, United Kingdom) published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Recommanded Product: 4,4-Diaminodicyclohexyl methane.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Zhao, Changchun published the artcileInterfacial combination of Ti₃C₂T_x MXene with waterborne epoxy anticorrosive coating, Safety of 4,4-Diaminodicyclohexyl methane, the publication is Applied Surface Science (2022), 150894, database is CAplus.

Interfacial combination of two-dimensional material composite coatings is one of the main factors affecting anti-corrosion performance of coatings. The surface of MXene are usually covered with active groups such as F, O, OH, etc. However, the interactions between active groups and epoxy mols. are still unclear. Here in, the adsorption stability and chem. bond types of Ti₃C₂Tx/epoxy structures with different surface groups were investigated by first-principles calculations The waterborne Ti₃C₂Tx/epoxy composite coatings were prepared by liquid phase blending method. The micro-structures, anticorrosion performance and compactness of the coatings were studied. Based on the theor. calculations, Ti₃C₂Tx shows excellent adsorption stability with epoxy mols., and the Ti₃C₂Tx with OH groups exhibited the best adsorption stability due to the formation of covalent bonds between OH groups and the epoxy groups (or benzene structures). The exptl. results show that, Ti₃C₂Tx nanosheets can disperse uniformly in the coating prepared by the liquid phase blending method. The micro-pores in composite coatings are improved, and the impedance modulus is 2 orders of magnitude much higher than that of pure epoxy coating. In this work, the studies of the adsorption behavior of Ti₃C₂Tx MXene to epoxy groups and benzene structures provide a reliable basis for the subsequent targeted regulation of the interaction between them.

Applied Surface Science published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C10H11FN2O2S, Safety of 4,4-Diaminodicyclohexyl methane.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Qin, Ruixuan published the artcileAlkali ions secure hydrides for catalytic hydrogenation, Application In Synthesis of 1761-71-3, the publication is Nature Catalysis (2020), 3(9), 703-709, database is CAplus.

Catalytic hydrogenation is one of the backbones of the chem. industry. Controlling the reaction behavior of the activated hydrogen species over oxide-supported metal catalysts is essential. Aside from the expected addition to substrates, the activated hydrogen species would also destroy the active structures. Here we show that, with the assistance of alkali cations, the atomically dispersed Ru(III) on Al₂O₃ exhibits enhanced performance in the hydrogenation of a broad range of substrates. The alkali cations facilitate the hydrogenation mediated by heterolytic hydrogen species, which not only restrain the hydride species from migrating to interfacial oxygen, thus suppressing the reduction and aggregation of ruthenium, but also stabilize the neg. charged transition states and intermediates through enhanced Columbic attraction. Distinctively, an inverse H/D isotope effect related to H₂ splitting as the rate-determining step over the atomically dispersed ruthenium-catalyzed hydrogenation is predicted and confirmed.

Nature Catalysis published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Application In Synthesis of 1761-71-3.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Li, Yan Mei published the artcileTailored modular assembly derived self-healing polythioureas with largely tunable properties covering plastics, elastomers and fibers, Formula: C13H26N2, the publication is Nature Communications (2022), 13(1), 2633, database is CAplus and MEDLINE.

To impart self-healing polymers largely adjustable dynamicity and mech. performance, here we develop libraries of catalyst-free reversible polythioureas directly from commodity 1,4-phenylene diisothiocyanate and amines via facile click chem. based modular assembly. By using the amine modules with various steric hindrances and flexibilities, the reversible thiourea units acquire triggering temperatures from room temperature to 120 °C. Accordingly, the derived self-healable, recyclable and controlled degradable dynamically crosslinked polythioureas can take effect within wide temperature range. Moreover, mech. properties of the materials can be tuned covering plastics, elastomers and fibers using (i) different assemble modules or (ii) solid-state stretching. Particularly, unidirectional stretching leads to the record-high tensile strength of 266 MPa, while bidirectional stretching provides the materials with biaxial strengths up to over 120 MPa. The mol. mechanism and technol. innovations discussed in this work may benefit promotion and application of self-healing polymers towards greatly diverse demands and scenarios.

Nature Communications published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Formula: C13H26N2.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Lu, Xiaoxin published the artcileNumerical modeling and experimental characterization of the AC conductivity and dielectric properties of CNT/polymer nanocomposites, Application In Synthesis of 1761-71-3, the publication is Composites Science and Technology (2020), 108150, database is CAplus.

In this work, we proposed a multiscale numerical model to estimate the elec. conductivity and dielec. constants of the CNT/polymer nanocomposites, taking into account the tunneling effect between neighboring CNTs separated at nanoscale and the frequency-dependent dielec. properties of each components. Finite element method was employed to solve the formulations, and the CNTs were modeled by highly conductive line segments in order to avoid the mesh problems. Experiments have been carried out in carbon nanotubes/epoxy nanocomposites in order to compare to the simulation results. The numerical estimations of the elec. conductivity are in good agreement with the exptl. measurement by network analyzers. Moreover, the calculated dielec. permittivity agrees with the exptl. data for the nanocomposites whose CNT content is beyond percolation threshold. Below percolation threshold, the proposed model also works well in the prediction of dielec. constants when the frequency is over 103Hz.

Composites Science and Technology published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Application In Synthesis of 1761-71-3.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

La Scala, John J. published the artcileEffect of methyl and methoxy substituents on dianilines for thermosetting polyimide system, Category: quinuclidine, the publication is High Performance Polymers (2020), 32(7), 801-822, database is CAplus.

4,4-Methylenedianiline (MDA) is widely used in high-temperature polyimide resins, including polymerization of monomer reactants-15. The toxicity of MDA significantly limits the manufacturability using this resin. Modifying the substitution and electronics of MDA could allow for the reduction of toxicity while maintaining the high-performing properties of the materials derived from the modified MDA. The addition of a single Me substituent, methoxy substituent, location of these substituents, and location of the amine relative to the phenolic bridge were modified as were other non-aniline diamines. Various anilines were condensed with paraformaldehyde under acidic conditions to yield dianilines. These dianilines and diamines were reacted with nadic anhydride and 3,3,4,4-benzophenonetetracarboxylic dianhydride in methanol to form the polyamic acid oligomers and heated at elevated temperature to form polyimide oligomers. It was found that the mol. weight of the oligomers derived from MDA alternatives was generally lower than that of MDA oligomers resulting in lower glass transition temperatures (T_gs) and degradation temperatures Addnl., methoxy substituents further reduce the T_g of the polymers vs. Me substituents and reduce the thermal stability of the resin. Methyl-substituted alternatives produced polyimides with similar T_gs and degradation temperatures The toxicity of the MDA alternatives was examined Although a few were identified with reduced toxicities, the alternatives with properties similar to that of MDA also had high toxicities.

High Performance Polymers published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Category: quinuclidine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Jiang, Yuan published the artcileBiomass-Based Polyureas Derived from Rigid Furfurylamine and Isomannide, Recommanded Product: 4,4-Diaminodicyclohexyl methane, the publication is ACS Applied Polymer Materials (2022), 4(3), 2197-2204, database is CAplus.

Polyureas are important com. polymers that are widely used in construction, automobile industry, military field, and coatings. Biomass-based amines are attractive feedstock in the synthesis of versatile polyureas. Furan-based diamine and isomannide-derived (Im-derived) diamine can be interesting monomers for such materials due to their renewability and intrinsic rigidity, but they have not been extensively studied. Herein, biomass-based polyureas were prepared by polymerizing dicarbamates derived from furfurylamine and isomannide. The dicarbamates were produced in multigram-scale quantities with high purity and yield. A series of polyureas with reasonably high mol. weights were subsequently prepared by condensing the dicarbamates with various diamines. ¹H NMR and ¹³C NMR spectroscopy confirmed the structure of the targeted copolymers. Exploration of thermal behavior by thermogravimetric anal. (TGA) and differential scanning calorimetry (DSC) revealed that the synthetic polyureas showed good thermal stability and glass-transition temperatures (T_g) ranging from 11 to 213°C.

ACS Applied Polymer Materials published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Recommanded Product: 4,4-Diaminodicyclohexyl methane.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Sim, Jee-Hyun published the artcileExperimental and Digimat-FE Based Representative Volume Element Analysis of Dye-Mixed Colored Resin and Carbon Fiber, Application of 4,4-Diaminodicyclohexyl methane, the publication is Polymers (Basel, Switzerland) (2022), 14(5), 1028, database is CAplus and MEDLINE.

Recently, the automobile industry has demanded weight reduction, so research on materials is being actively conducted. Among this research, carbon fiber-reinforced composite materials are being studied a lot in the automobile industry due to their excellent mech. properties, chem. resistance, and heat resistance. However, carbon fiber-reinforced composite materials have disadvantages, in that they are not free from color selection, and have weak interfacial bonding strength. In this study, a colored epoxy resin was prepared by mixing epoxy-which is a thermosetting resin according to the pigment concentration (0.1, 0.3, 0.5, 1.0 wt%)-and curing shrinkage. Thermal expansion characteristics were analyzed and the concentration of 0.5 wt% pigment showed the lowest shrinkage and thermal expansion characteristics. In addition, to measure the interfacial shear strength (IFSS) of the carbon fiber and the colored epoxy resin, the IFSS was obtained by performing a microdroplet debonding test, and the strength of the pigment concentration of 0.5 wt% was reduced to a relatively low level. Through these experiments, it was determined that an epoxy resin in which 0.5 wt% pigment is mixed is the optimal condition. Finally, using the composite material modeling software (Digimat 2020.0), the representative volume element (RVE) of the meso-scale was set, and interfacial properties of carbon fibers and colored epoxy resins were analyzed by interworking with general-purpose finite element anal. software (Abaqus CAE).

Polymers (Basel, Switzerland) published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C17H19N3O6, Application of 4,4-Diaminodicyclohexyl methane.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Lai, Chiu-Chun published the artcileSynthesis and properties of low-crystallinity nylon 6 with high transparency and low hygroscopicity containing adipic acid, Safety of 4,4-Diaminodicyclohexyl methane, the publication is Modern Physics Letters B (2020), 34(7/9), 2040005, database is CAplus.

In this research, a series of amorphous nylons 6 were prepared by introducing adipic acid and different structure amines into the copolymerization with caprolactam. The effects including thermal properties, crystallinity, dynamic mech. properties, optical properties, and water absorption of different copolymerization structure and copolymerization ratio on the properties of nylon 6 were investigated. The results show the m.p. and thermal cracking temperature Td 5 of nylon 6 are, resp., between 179°C and 217°C and 278°C to 336°C. Nylon 6 structure introducing a Me side chain is more effective than a meta-benzene ring, a meta-cycloalkyl, and bicycloalkyl groups, so CAMM and CAI have the lowest crystallinity.

Modern Physics Letters B published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Safety of 4,4-Diaminodicyclohexyl methane.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider