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Production and Characterization of Bio-based Polyols and Polyurethanes from Biodiesel-derived Crude Glycerol and Lignocellulosic Biomass

Hu, Shengjun
http://rave.ohiolink.edu/etdc/view?acc_num=osu1374051355

Abstract Details

2013, Doctor of Philosophy, Ohio State University, Food, Agricultural and Biological Engineering.
Abstract This study focused on the development of bio-based polyols and polyurethanes (PU) from biodiesel-derived crude glycerol and lignocellulosic biomass. Polyols were produced via liquefaction of lignocellulosic biomass using crude glycerol as a liquefaction solvent. The polyols produced were used directly to prepare PU foams. The effects of liquefaction parameters on the properties of polyol and PU foams were investigated. Under optimal liquefaction conditions, the polyols and PU foams produced had properties comparable to their analogs derived from petrochemical solvent-based liquefaction processes. Certain impurities in crude glycerol are critical for the improvement of polyol and PU foam properties. The composition of five representative biodiesel-derived crude glycerol samples was determined to identify their components. All crude glycerol samples contained glycerol, soap, methanol, FAMEs (methyl esters of fatty acids), water, glycerides, FFAs (free fatty acids), and ash, but their proportions varied widely with the origins of crude glycerol. The effects of crude glycerol impurities on the properties of polyols and PU foams derived from base- and acid-catalyzed biomass liquefaction processes were studied. For both liquefaction processes, increasing levels of organic impurities (i.e. FFA, FAMEs, and glycerides) in crude glycerol decreased biomass conversion and polyol hydroxyl numbers and increased polyol molecular weight. The presence of suitable amounts of organic impurities, especially FFA and FAMEs, in crude glycerol improved the properties of polyols and PU foams produced. For both processes, valid regression models (R2=0.99) were developed to predict the hydroxyl numbers of polyol from the contents of organic impurities in crude glycerol. In contrast to their negligible effects on the base-catalyzed process, inorganic salts, including NaCl and Na2SO4, negatively affected the properties of polyols produced from the acid-catalyzed process. A two-step sequential biomass liquefaction process was developed to combine the advantages of the acid- and base-catalyzed liquefaction processes. The first, acid-catalyzed, step rapidly liquefied biomass and promoted the esterification reactions between glycerol and FFA, while the second, base-catalyzed, step facilitated extensive condensation reactions such as transesterification and etherification that occurred among liquefaction components. The polyols and PU foams produced showed improved properties over their analogs derived from the acid- or base-catalyzed process alone. A crude glycerol sample was used as a sole feedstock to produce polyol via a thermochemical conversion process. The polyol produced from optimal reaction conditions was used to prepare waterborne PU dispersions for coating applications. PU films cast from the prepared dispersions had relatively high glass transition temperatures (Tg, 63-81 °C) that increased with increasing hard segment contents in PU (41-63.2 %), and good thermal stability up to approximately 240 °C. PU coatings prepared from the produced PU dispersions had excellent adhesion and hardness properties, but relatively low flexibility on steel panels. The properties of polyols and PU produced in this study compare well to their analogs derived from petrochemical-solvent based liquefaction processes. Furthermore, crude glycerol alone also has the potential to produce bio-based polyol and PU. The optimization of crude glycerol composition and polyol production processes are crucial to the success of crude glycerol-based polyol production.
Yebo Li (Advisor)
223 p.
Agricultural Engineering; Energy; Engineering; Materials Science; Polymers
Crude glycerol; Lignocellulosic biomass; Liquefaction; Polyol; Polyurethane; Foam; Impurities; Waterborne; Coating; Biomass;

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Citations

  • Hu, S. (2013). Production and Characterization of Bio-based Polyols and Polyurethanes from Biodiesel-derived Crude Glycerol and Lignocellulosic Biomass [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374051355

    APA Style (7th edition)

  • Hu, Shengjun. Production and Characterization of Bio-based Polyols and Polyurethanes from Biodiesel-derived Crude Glycerol and Lignocellulosic Biomass . 2013. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1374051355.

    MLA Style (8th edition)

  • Hu, Shengjun. "Production and Characterization of Bio-based Polyols and Polyurethanes from Biodiesel-derived Crude Glycerol and Lignocellulosic Biomass ." Doctoral dissertation, Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374051355

    Chicago Manual of Style (17th edition)

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This open access ETD is published by The Ohio State University and OhioLINK.
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