Fabrication and Characterization of Electrospun Poly(acrylonitrile-co-Methyl Acrylate)/Lignin Nanofibers: Effects of Lignin Type and Total Polymer Concentration

Abstract

Lignin macromolecules are potential precursor materials for producing electrospun nanofibers for composite applications. However, little is known about the effect of lignin type and blend ratios with synthetic polymers. This study analyzed blends of poly(acrylonitrile-co-methyl acrylate) (PAN-MA) with two types of commercially available lignin, low sulfonate (LSL) and alkali, kraft lignin (AL), in DMF solvent. The electrospinning and polymer blend solution conditions were optimized to produce thermally stable, smooth lignin-based nanofibers with total polymer content of up to 20 wt % in solution and a 50/50 blend weight ratio. Microscopy studies revealed that AL blends possess good solubility, miscibility, and dispersibility compared to LSL blends. Despite the lignin content or type, rheological studies demonstrated that PAN-MA concentration in solution dictated the blend’s viscosity. Smooth electrospun nanofibers were fabricated using AL depending upon the total polymer content and blend ratio. AL’s addition to PAN-MA did not affect the glass transition or degradation temperatures of the nanofibers compared to neat PAN-MA. We confirmed the presence of each lignin type within PAN-MA nanofibers through infrared spectroscopy. PAN-MA/AL nanofibers possessed similar morphological and thermal properties as PAN-MA; thus, these lignin-based nanofibers can replace PAN in future applications, including production of carbon fibers and supercapacitors.

Electrohydrodynamic Processing of PVP-Doped Kraft Lignin Micro- and Nano-Structures and Application of Electrospun Nanofiber Templates to Produce Oleogels

“…These fibers have significant advantages for several applications such as being extremely lightweight, and their low-cost production, large aspect ratio with reduced defects (small and uniform diameters), high molecular orientation, and flexibility in surface functionality [ 27 , 35 ]. Others researchers have been succeeded in producing electrospun lignin fibers, but each study focused on a single type of lignin, hence it is difficult to translate the findings related to one type of lignin to another [ 36 , 37 , 38 ].…”

Acrylonitrile and Pullulan Based Nanofiber Mats as Easily Accessible Scaffolds for 3D Skin Cell Models Containing Primary Cells

“…Less attention has been drawn to the potential of synthetic or polysaccharide-based polymers such as acrylonitrile or pullulan without the incorporation of specific bioactive molecules. First reports indicate that, due to their pore size and fiber diameter, electrospun PAN nanofiber scaffolds are suitable in soft tissue regeneration [15,49], and specifically for growing fibroblast [50,51]. Pure PAN nanofibers were shown to allow high cell growth rates and additives, such as gelatin, can have a positive effect on skeletal muscle cells by e.g., improving cell differentiation [52,53].…”

Preparation and Stabilization of High Molecular Weight Poly (acrylonitrile-co-2-methylenesuccinamic acid) for Carbon Fiber Precursor

“…As we know that stabilization is the structural change process that allows the structure to change from a linear structure to a ladder structure, this coincides with the peak intensity changes at around 2θ = 17°. Hence, the peak intensity changes can be used to assess the degree of stabilization according to Figure 9a,b, and SI is presented in the equation below [25,27,28]: 𝑆𝐼 = (𝐼 0 − 𝐼 𝑆 )/𝐼 0 (9) where 𝐼 𝑆 represents the strength of peak at around 2𝜃 = 17° after being heated 200 °C for 30 min, and 𝐼 0 is the peak intensity at around 2𝜃 = 17° of the original P (AN-co-MLA). Based on the results in Table 4, the SI value of the PAN homopolymer is negative because the stabilization has not started.…”

“…To solve these problems, a small quantity of comonomers is usually introduced to the PAN polymer chains to reduce the intermolecular force and to improve the stabilization. The most used monomers are acidic comonomers, such as itaconic acid (IA) [8], and neutral comonomers, such as as methyl acrylate (MA) [9,10] and methacrylate (MMA) [11]. IA can promote the stabilization through ionic cyclization reactions with a lower initiation temperature and with a smaller activation energy due to the fact that IA contains two carboxyl groups.…”