What is the chemical reaction between acetic acid and hydrogen peroxide?5 answersThe chemical reaction between acetic acid and hydrogen peroxide can lead to the formation of peracetic acid. Peracetic acid is a significant organic peroxide in the atmosphere, with its reaction kinetics with OH being a major sink. The synthesis of peracetic acid can be achieved through a continuous method involving the mixing of acetic acid and hydrogen peroxide in specific ratios, followed by a reaction catalyzed by a solid acid catalyst in an immobilized reactor. The use of Amberlyst 15Dry catalyst can enhance the formation of peracetic acid by reducing the spontaneous decomposition of the peracid formed during noncatalytic synthesis. This reaction is crucial as peracetic acid has implications in atmospheric chemistry and can be formed through various pathways involving acetic acid and hydrogen peroxide.
How does the acrylamid can in oil industry affect the thermal stability of pva hydrogel?5 answersThe acrylamide in oil industry affects the thermal stability of PVA hydrogel by influencing the polymer chains and cross-linker bonds. Acrylamide-based gels, when exposed to high temperatures, can suffer from thermal stability loss due to the rupture of polymer chains and breakage of cross-linker chains. The presence of acrylamide, along with other raw materials like AMPS, can lead to the formation of interpenetrating three-dimensional network polymer gels with enhanced thermal stability in high-temperature and high-salinity conditions. By incorporating acrylamide into the gel system, the resulting hydrogel can exhibit stable continuous entanglement at elevated temperatures, showcasing satisfactory thermal stability and self-healing properties. Therefore, acrylamide plays a crucial role in influencing the thermal stability and performance of PVA hydrogels in oil industry applications.
What role does hydrogen bonding play in PVA films?4 answersHydrogen bonding plays a crucial role in the mechanical properties of polyvinyl alcohol (PVA) films. The presence of hydrogen bonds in PVA is important for stretchability and mechanical performance. Different types of hydrogen bonds in PVA films can be discriminated and quantitatively determined using various techniques such as DMA, IR spectroscopy, MD simulation, and solid-state 13C-NMR. Incorporating small molecular chemicals as plasticizers into the PVA matrix allows for the regulation of hydrogen bonding interactions and the stretchability of the films. Additionally, the introduction of compounds containing phosphorus and nitrogen with multiple hydrogen-bonding reaction sites enhances the flame retardancy of PVA films. The thermal conductivity and stability of PVA films can be significantly improved by incorporating carbon nanomaterials through hydrogen-bond self-assembly. Furthermore, the establishment of strong hydrogen bonding interactions between graphitic carbon nitride nanosheets and PVA leads to enhanced mechanical properties in PVA nanocomposites. The rheological behavior of PVA aqueous solutions is also influenced by intermolecular hydrogen bonding interactions.
Why radical of vinyl acetate has high reactivity?4 answersThe high reactivity of the radical of vinyl acetate can be attributed to several factors. Firstly, density functional theory (DFT) calculations showed that the ‘Samanos’ reaction mechanism, which involves the direct coupling of coadsorbed ethylene and acetate species, is more favorable for vinyl acetate synthesis. Additionally, the radical polymerization of vinyl acetate has been found to have lower rate constants compared to vinyl benzoate, indicating that the poly(vinyl benzoate) radical is more reactive than the poly(vinyl acetate) radical. Furthermore, the presence of fluoroalcohols in the polymerization of vinyl acetate has been shown to increase the polymerization rate, suggesting that the interaction of solvents with the ester side groups of the monomers and growing radical species enhances reactivity. Overall, the high reactivity of the radical of vinyl acetate can be attributed to the specific reaction mechanisms and the influence of solvents on the polymerization process.
Can CNCs, PDA, and PVA hydrogel be used for wet spinning ?5 answersCNCs, PDA, and PVA hydrogel can be used for wet spinning. Wet spinning has been used to produce composite fibers composed of polymers loaded with CNTs. PVA material with common molecular weight has been spinned using wet spinning. PVA gel suitable for PVA fibers has been obtained by gel spinning using dry and wet spinning method. PVA composites fibers with a large fraction of multi-walled carbon nanotubes (MWNTs) have been produced by wet-spinning. PVA fibers with high strength and high Young's modulus have been prepared by dry-wet spinning.
How can FTIR be used to characterize PVA/CMC hydrogels and their hydrogels containing essential oil?5 answersFTIR can be used to characterize PVA/CMC hydrogels and their hydrogels containing essential oil. The FTIR spectrum can show the chemical structure characteristics of the hydrogels. For PVA/CMC hydrogels, the FTIR spectrum can show the characteristic wave numbers of CMC and PVA, which can confirm the reaction between the two polymers. For hydrogels containing essential oil, the FTIR spectrum can provide information about the incorporation of the active compound and its effect on the hydrogel structure. By analyzing the FTIR spectrum, researchers can determine the presence of specific functional groups and confirm the successful synthesis of the hydrogels. Overall, FTIR is a valuable tool for characterizing the chemical structure and composition of PVA/CMC hydrogels and their hydrogels containing essential oil.