A Study on the Improvement of Using Raw Lacquer and Electrospinning on Properties of PVP Nanofilms

Abstract

Raw lacquer (RL), ethanol being used as the solvent, was added to polyvinyl pyrrolidone (PVP) and then electrospun into RL/PVP nanofilms. Manufacturing parameters such as RL/PVP ratio, voltage, flow velocity, needle type, and the distance between syringe and the collection board were systematically investigated. A scanning electronic microscope (SEM) was used to observe the surface morphology of nanofilms; the block drop method was used to measure the water contact angle; the mechanical properties of RL/PVP nanofilms of different proportions were tested by universal material testing machine; and Fourier-transform infrared spectroscopy (FT-IR) was used to characterize the structure. Based on the water resistance and acid resistance measurements, the proposed nanofilms demonstrated to be water and acid resistant were successfully produced. The results show that PVP that melts in water becomes incompatible with water after adding raw lacquer, and the acid resistance is greatly improved. Furthermore, the smaller the fiber diameter, the better the mechanical properties of the nanofilms are under low ratio of RL/PVP. With a high proportion of RL/PVP, the inner structure of the nanofilm is denser, and the water resistance and acid resistance are better. The dense structure can protect the inner material of the nanofilms.

Superhydrophilic PLGA-Graft-PVP/PC Nanofiber Membranes for the Prevention of Epidural Adhesion

“… 21 , 22 Compared to the spectrum of PLGA, the spectra of PLGA-g-PVP and PLGA-g-PVP/PC revealed a small peak at 1661 cm −1 , which originated from the stretching vibrations of C=O bonds and indicated the successful grafting of PVP. 23 Compared to the spectrum of PLGA-g-PVP, the spectrum of PLGA-g-PVP/PC presented more characteristic peaks, which might be caused by the chemical bonding diversity in PC. The peaks of PLGA-g-PVP/PC included a small band at 3380 cm −1 , which was related to the asymmetric stretching vibrations of NH2 bonds.…”

Nano-emulsification of oriental lacquer sap by ultrasonic wave propagation: Improvement of thin-film characteristics as a natural resin

“…Notably, the quinone-radicals generated from laccase-catalysed urushiol transfers to form oligomers, and the cross-links of long aliphatic unsaturated chains by auto-oxidation with oxygen leads to lacquer polymerisation [12] , [18] . As a result, the peak intensities of 1278 cm −1 and 1189 cm −1 due to γ O–H and C–O vibration of the C–O–H group gradually decreased, while a broad peak at 1205 cm −1 appeared instead of a peak at 1189 cm −1 with an increase in polymerisation, indicating that the O–H of the phenyl ring was involved in the polymerisation [3] , [19] , [21] . Indeed, the decrease in the peak at 734 cm −1 indicates an additional substitution on the phenyl ring.…”

“…The enzyme-catalysed polymerisation of oriental lacquer sap collected from lacquer trees in Asia allows it to be used as an energy-saving and environmentally friendly coating material with antibacterial, antiseptic, waterproof, and chemically resistant actions [1] , [2] , [3] , [4] , [5] , [6] , [7] . The lacquer thin films ensure excellent physicochemical properties such as high thermal stability, superior durability, anti-corrosiveness, good adhesion, and high gloss [8] , [9] , [10] .…”

Photo-Curable Lacquer Sap Resin Based on Urushiol-Mimicking, Tyrosine-Containing Additive

“…We hypothesized that UV-curable natural resins containing an urushiol-mimicking Y-ADDA additive would dramatically reduce LSS drying time due to tyrosine−tyrosine polymerization promoted by a W/O emulsion of LSS based on the coassembly of photo-cross-linkable Y-ADDA and urushiol (Scheme 2 and Figure S4). 35 LSS films were fabricated with different additives [Fmoc-Tyr(tBu)-OH, shellac, and Y-ADDA] at different concentrations (0.001, 0.01, 0.05, and 0.1 equiv), and their drying times were measured. The LSS was cast onto glass without any aggregations and cured under UV light with a wavelength of 254 nm (25 °C, ∼50% RH, Figure S5c).…”