High Bio-Content Thermoplastic Polyurethanes from Azelaic Acid.

To realize the commercialization of sustainable materials, new polymers must be generated and systematically evaluated for material characteristics and end-of-life treatment. Polyester polyols made from renewable monomers have found limited adoption in thermoplastic polyurethane (TPU) applications, and their broad adoption in manufacturing may be possible with a more detailed understanding of their structure and properties. To this end, we prepared a series of bio-based crystalline and amorphous polyester polyols utilizing azelaic acid and varying branched or non-branched diols.

Laboratory Ozonolysis Using an Integrated Batch-DIY Flow System for Renewable Material Production.

Flow chemistry offers a solution for replacing batch methods in chemical preparation where intermediates or products may pose toxicity or instability hazards. Ozonolysis offers an ideal opportunity for flow chemistry solutions, but multiple barriers to entry exist for use of these methods, including equipment cost and performance optimization. To address these challenges, we developed a programmable DIY syringe pump system to use for a continuous flow multireactor process using 3D-printed parts, off-the-shelf stepper motors, and an Arduino microcontroller.

Renewable Polyurethanes from Sustainable Biological Precursors.

Due to the depletion of fossil fuels, higher oil prices, and greenhouse gas emissions, the scientific community has been conducting an ongoing search for viable renewable alternatives to petroleum-based products, with the anticipation of increased adaptation in the coming years. New academic and industrial developments have encouraged the utilization of renewable resources for the development of ecofriendly and sustainable materials, and here, we focus on those advances that impact polyurethane (PU) materials. Vegetable oils, algae oils, and polysaccharides are included among the major renewable resources that have supported the development of sustainable PU precursors to date.

Fluorescence control of chitin and chitosan fabricated surface functionalization using direct oxidative polymerization.

The copolymer of 3-hexylthiophene (3HT) and fluorene (F) was directly grafted onto chitin and chitosan using FeCl as an oxidant. The properties of the grafted chitin/chitosan were characterized by Fourier transform infrared (FT-IR) spectroscopy, UV-Vis spectroscopy, fluorescence spectroscopy, X-ray diffraction analysis, thermogravimetric analysis (TGA), transmission electron microscopy-energy dispersive X-ray spectroscopy, and quantum yield measurements. The UV-Vis absorption peaks of the chitin/chitosan grafted with 3-hexylthiophene and fluorene copolymer were increasingly blue-shifted upon increasing the fluorene content and the red-shifted emission of the grafted chitin/chitosan were controlled by varying the monomers feed of the 3HT/F units.

Surface functionalization of cellulose with poly(3-hexylthiophene) via novel oxidative polymerization.

Surface functionalization of cellulose with poly(3-hexylthiophene) (P3HT) was conducted with FeCl as an oxidant in three different solvents: acetonitrile, chloroform, and hexane. Of these three solvents, hexane best promoted the grafting P3HT to cellulose with a high grafting ratio and molecular weight. The maxima of the UV-vis absorption and fluorescent spectra, observed at around 500 and 600nm, respectively, represented the build-up of the conjugated chain length formed by the grafting of P3HT onto the cellulose surface.

Photoluminescence Control of Cellulose via Surface Functionalization Using Oxidative Polymerization.

Control of the photoluminescence properties of cellulose is conducted by introduction of conducting polymers including fluorene (F) and 3-hexylthiophene (3HT) on cellulose surface through FeCl oxidative polymerization. The UV-vis absorption peak of cellulose grafted with the 3-hexylthiophene and fluorene copolymer was increasingly blue-shifted with increasing fluorene content and the shift in the peak position in photoluminescence spectra depend on the initial 3HT:F ratio of the copolymer. The crystallinity and thermal stability of cellulose decreased slightly upon graft polymerization with PF and P3HT, while the quantum yield, determined using absolute methods, increased from 3.