Guaiacol and hydroxypropyl-guaiacol were taken as model compounds for lignins and hydroxypropyl lignins to study their vinylation and copolymerization behaviors. Lignin model compounds and lignin were subjected to reaction with isocyanatoethyl methacrylate (IEM) using dibutyltin dilaurate as catalyst. The acrylate derivatives were characterized by elemental analysis, UV, IR, ¹H-NMR, and ¹³C-NMR spectroscopy. The acrylated lignin model compounds, guaiacol-IEM urethane (GIU) and hydroxypropyl-guaiacol-IEM urethane (HPGIU), were copolymerized with methyl methacrylate (MMA) and styrene (St) through free radical mechanism. Solution copolymerizations in 1,2-dichloroethane: ethanol were initiated by benzoyl peroxide. The monomer reactivity ratios were investigated for these copolymerization combinations. The copolymer compositions were analyzed by UV for GIU-co-MMA and HPGIU-co-MMA, while methoxyl content determination by HI-GC was used to determine compositions of styrene-based copolymers. The copolymers were characterized by gel permeation chromatography (GPC), and by IR and NMR spectroscopy. The reactivity ratios were computed by use of the Fineman-Ross linearization method, by the KelenTudos equation and by the Yezrielev-Brokhina-Roskin (YBR) numerical method. A comprehensive analysis with respect to the methods used to derive the ratios has shown that the Kelen-Tudos method and the YBR method produce diagnostic reactivity ratios. A great copolymerization tendency of lignins and hydroxypropylated lignins is predicted from the reactivity ratios of the lignin models. A statistical treatment of the model reactivity ratios lead to prediction for chain sequence length distribution of the copolymers formed. Hydroxybutyl lignin IEM urethanes (HBLIU's) were copolymerized with a vinyl-terminated poly(butadiene-acrylonitrile) macromer and MMA to study the copolymerization behaviors of macromolecular lignin acrylate derivatives. The crosslinked films with desired properties were cast from methylene chloride, with benzoyl peroxide as an initiator. The copolymerized network polymers were characterized by sol fraction measurements, differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and by scanning electron microscopy (SEM). The influences of vinyl content in lignin acrylate derivatives and the ratio of lignin derivatives to vinyl monomer or macromer were studied with respect to structure-property relationship in the copolymers. / M.S.

A lignin epoxide resin was synthesized and characterized. The epoxidation reaction was studied by reacting hydroxypropylated guaiacol (a lignin-like model compound) and epichlorohydrin using a catalyst system of potassium hydroxide and a phase transfer catalyst in toluene. The parameters studied were different epichlorohydrin level and temperature. The reaction was followed by HPLC and the structure of the product was identified with IR, ¹H and ¹³C NMR spectroscopy. The lignin epoxide was synthesized by reacting hydroxyalkylated (hydroxypropyl and hydroxybutyl) lignin with epichlorohydrin using the reaction conditions defined by the model compound studies. The reaction was studied at different epichlorohydrin level and at elevated and room temperature. The epoxy content of the lignin epoxide was determined by titration with HBr and its structure was identified with IR, ¹H and ¹³C NMR spectroscopy. Lignin epoxides were cured by crosslinking with a diamine and with phthalic anhydride. An amine-terminated rubber was added as toughening agent. Sol fraction and swelling behavior, stress-strain behavior and dynamic mechanical behavior of the cured lignin epoxides were studied in relation to cure conditions. / M.S.

Indiana University-Purdue University Indianapolis (IUPUI) / Phytoestrogens that abound in soy products, legumes, and chickpeas can induce biologic responses in animals and humans due to structural similarity to 17β-estradiol. Although experimental studies suggest that phytoestrogen intake may alter the risk of cancer and cardiovascular disease, few epidemiologic studies have investigated this research question. This dissertation investigated the associations of intake of total and individual phytoestrogens and their urinary biomarkers with these chronic conditions using data previously collected from two US national cohort studies (NHANES and PLCO). Utilizing NHANES data with urinary phytoestrogen concentrations and follow-up mortality, Cox proportional hazards regression (HR; 95% CI) were performed to evaluate the association between total cancer, cardiovascular disease, and all-cause mortality and urinary phytoestrogens. After adjustment for confounders, it was found that higher concentrations of lignans were associated with a reduced risk of death from cardiovascular disease (0.48; 0.24-0.97), whereas higher concentrations of isoflavones (2.14; 1.03-4.47) and daidzein (2.05; 1.02-4.11) were associated with an increased risk. A reduction in all-cause mortality was observed for elevated concentrations of lignans (0.65; 0.43-0.96) and enterolactone (0.65; 0.44-0.97). Utilizing PLCO data and dietary phytoestrogens, Cox proportional hazards regression examined the associations between dietary phytoestrogens and the risk of prostate cancer incidence. After adjustment for confounders, a positive association was found between dietary intake of isoflavones (1.58; 1.11-2.24), genistein (1.42; 1.02-1.98), daidzein (1.62; 1.13-2.32), and glycitein (1.53; 1.09-2.15) and the risk of advanced prostate cancer. Conversely, an inverse association existed between dietary intake of genistein and the risk of non-advanced prostate cancer (0.88; 0.78-0.99) and total prostate cancer (0.90; 0.81-1.00). C-reactive protein (CRP) concentration levels rise in response to inflammation and higher levels are a risk factor for some cancers and cardiovascular disease reported in epidemiologic studies. Logistic regression performed on NHANES data evaluated the association between CRP and urinary phytoestrogen concentrations. Higher concentrations of total and individual phytoestrogens were associated with lower concentrations of CRP. In summary, dietary intake of some phytoestrogens significantly modulates prostate cancer risk and cardiovascular disease mortality. It is possible that these associations may be in part mediated through the influence of phytoestrogen intake on circulating levels of C-reactive protein.