Date of Award

Summer 8-10-2018

Level of Access

Open-Access Thesis

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Advisor

William M. Gramlich

Second Committee Member

Brian Frederick

Third Committee Member

Matthew Brichacek

Additional Committee Members

Barbara Cole

Bruce Jensen

Abstract

Limited fossil resources have raised research focus on synthesizing novel, sustainable polymers and renewably sourcing existing petroleum based polymers. This work presents the synthesis and ring opening polymerization (ROP) of a new functionalized lactone monomer, methoxy-δ-hexalactone (MDHL), to yield a functionalized polyester (polyMDHL). MDHL can be renewably sourced from hydroxymethylfurfural, a renewable platform chemical. MDHL was synthesized from methyl cyclopentanone-2-carboxylate by a five-step synthesis with a global yield of 23%. ROP of MDHL was conducted with benzyl alcohol initiator, catalyzed by diphenyl phosphate. 1H Nuclear Magnetic Resonance spectroscopy verified polyMDHL chemical structure. Targeting higher molecular weights for polyMDHL by increasing the monomer/initiator ratio (M/I), was not achieved due to complexity of the polymerization mechanism. Polymerization proceeds via an activated monomer mechanism (AM), and an active chain end mechanism (ACE) at higher M/I. End group analysis using matrix assisted laser desorption ionization-mass spectrometry (MALDI-TOF-MS) revealed presence of three polymer chain populations with benzyl alcohol, water, and methanol end groups. This observation is supported by ACE mechanism that can undergo rearrangements and side reactions to generate different end groups. These results show successful synthesis and purification of a novel functional lactone and the feasibility of its polymerization. This work also focused on renewably sourcing the phenolic content of phenol-formaldehyde (PF) resins using lignin bio-oil. Traditional lignin bio-oil have limited utility to completely replace phenol in resins with its complex mixture of alkyl-functionalized guaiacol and syringol monomers. Formate assisted fast pyrolysis (FAsP) of lignin yielded a bio-oil rich in alkylated phenol compounds. A solvent extraction method was developed to concentrate the phenolics. Phenolic resins were synthesized using phenol (phenol resin), FAsP bio-oil (oil resin), and a mimic representing the purified phenol rich extract (mimic resin). All three phenolic sources could synthesize novolac resins that could undergo resin curing. Thermal and decomposition properties and adhesive strength of phenol and the mimic resins were superior to those of the oil resins. These results confirmed that extracting a mixture of substituted aromatics from FAsP bio-oil could synthesize resins with properties similar to those from phenol and improved over the parent bio-oil.

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