ABSTRACT
Nanofibers possess high surface area to volume ratios and are particularly attractive for a variety of applications including tissue regeneration, drug delivery, fiber-reinforced composites, filtration, and protective clothing. Though the production of nanofibers from common thermoplastic polymers is relatively well-demonstrated, processing constraints have limited high throughput manufacturing of nanofibers from high performance polymers. This has in turn limited broad technological exploitation of polymer nanofibers in areas such as hot chemical filtration or high-performance lightweight composites for aerospace and defense applications. We report here that nanofibers can be produced in a solventless high throughput process from polymers such as poly(butylene terephthalate) (PBT) using a newly developed technology termed "Forcespinning" that employs centrifugal force to attenuate fibers. Our investigations also show that these nanofibers have a high crystallinity and enhanced molecular orientation which is important for realizing desirable physical and chemical properties of many high-performance polymer fibers.
ABSTRACT
Thiol-ene chemistry was harnessed to enable production of thermochemically stable thermoset fibers containing 50-87 wt % acrylated epoxidized soybean oil and 49-72% biobased carbon without using solvent or heat. In this demonstration, the fibers were made by simultaneous electrospinning and photocuring of a liquid monomer mixture, which could be translated to other fiber manufacturing processes such as melt blowing or Forcespinning. Scanning electron micrographs illustrate the fiber quality and an average diameter of about 30 µm. Photochemical conversion kinetics of functional groups during light exposure were measured by real-time Fourier transform infrared spectroscopy, providing insight into the advantages of using high-functionality monomers and thiol-ene chemistry in this application.
