| Studies were undertaken to analyze and understand the relationships and structural properties associated with oligoesters in dispersions and coatings. Particular emphasis was given to the relationship of molecular structure, to hydrolysis, and the mechanical properties of oligoester-urethanes. In addition, ceramers from seed oils were cured using UV-radiation. Overall, this research elucidates ester group contribution and a novel ceramer coating.; Anchimeric and steric effects involved in scission were studied with the adjunct group contribution of cyclic and acyclic esters. Hydrolytic investigations proceeded via dispersed acetone, water, and ester mixtures, and were evaluated by acid concentration and molecular weight shift. The results indicate that functional end groups favor anchimeric interactions, while steric groups control main chain hydrolysis. In addition, a model for introducing a relative hydrolytic rate was established.; Incorporating these esters, a series of urethane coatings was tested in an accelerated weathering chamber. Property retention was the tangible manifestation evaluated in relation to Tg and stability. Substrate corrosion was limited by hydrolytic stability and higher Tg, whereas gloss retention was mainly influenced by the Tg.; Overall, the ability of polyester to curtail deformation is based on the chemical structure. Tensile and Tukon properties were found to be dependent on the Tg. A correlation of scratch resistance relative to fracture properties of the film was not observed.; Ceramers were UV-cured using an epoxy-modified triglyceride and combinations of sol-gel precursors: titanium (IV) isopropoxide (TIP), tetraethyl orthosilicate (TEOS), and TEOS functional oligomers (TFC). Ceramers containing TEOS and TFC improved hardness and solvent resistance without reducing impact strength. These results conclusively indicate a transition in properties when the film composition was formulated between five and ten percent TIP. Maximum UV absorbance and minimum contact angle were found to be independent of a concentration near ten percent TIP. |
