Glenn Lewis Shoaf

Alkyd/Acrylic Hybrid Latexes with Enhanced Oxidative Curing

Development of low or near zero volatile organic content (VOC) containing coatings has become a high priority for the coatings industry. As a result traditional solvent‐borne resins such as alkyds have come into disfavor relative to waterborne resins such as acrylic based latexes. However, some combinations of properties such as ambient curing and high gloss have been difficult to achieve with acrylic‐based latexes. Blends of alkyds and acrylic based latexes often suffer from incompatibility of the two polymer types resulting in hazy or non‐uniform films. Properly designed hybrid systems, however, overcome compatibility issues associated with blends and generate property combinations that can not be obtained with either polymer system alone. Miniemulsion polymerization provides an effective processing method for combining alkyd and acrylic based polymers and delivering the resultant hybrid as a waterborne latex. This work describes the development of alkyd/acrylic hybrid latexes made via a miniemulsion polymerization process. Moreover, it describes how oxidative curing of the resultant polymer film can be markedly enhanced through the use of latent‐oxidative functional monomers.

Surface Active Properties of Polyester Surfactants with Applications to Seeded Emulsion Polymerization

ABSTRACTThe surface active properties of polyester surfactants on latexes of variable composition are reported. The method of soap titration was used to analyze surfactant efficiency and effectiveness. Adsorption isotherms were also generated for five polyesters on poly(styrene), poly(styrene/poly(methyl methacrylate) [1:1 weight ratio], and poly(methyl methacrylate) latex. The polyester composition varied in the amount of charged species and the structure of the glycol units. Seeded semicontinuous polymerizations were performed with the polyester surfactants and related to the adsorption behavior of the polyesters.