Water whitening resistance of pressure-sensitive adhesives obtained from high solids content acrylic dispersions is studied. The effect of the pH and surfactant system on the water whitening of the final films is investigated. The pH used throughout the polymerization process and the pH at which the final latex is adjusted just before the application have a substantial influence on the water whitening resistance. The performance of films obtained from latexes stabilized using conventional surfactant is compared to that of latexes stabilized using polymerizable surfactant or polymerizable stabilizer. In the films containing the conventional anionic surfactant, the water whitening phenomenon is affected by two counteracting mechanisms: latex stability and excess of surfactant in the aqueous phase. However, when polymerizable surfactants or stabilizer are used, due to their incorporation into the polymer backbone, no effect of the surfactant excess is observed leading to films with superior performance increasing their concentration. Macromol. Mater. Eng. 2015, 9, 925-936 ß 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 926 www.MaterialsViews.comN/D not determined. a) Per liter of water (mmol Á L -1 ); b) measured by DLS; c) measured by HPLC-ELSD.
Hybrid nanofibers containing CdSe/ZnS quantum dots have been produced by electrospinning of hybrid latexes to characterize the electro-optical behavior of this novel luminescent sensing material. The latexes are synthesized by seeded semi-batch emulsion polymerization yielding crosslinked core-shell PS/QDs/PMMA particles with efficiently encapsulated quantum dots guaranteeing a good optical stability. Addition of polyvinyl alcohol (PVA) or polyethylene oxide (PEO) to the latexes is necessary to produce polymeric dispersions suitable for electrospinning manufacture of the nanometric fibers. The optimized polymeric dispersions are successfully electrospun obtaining fluorescent nanofibers in both cases. The hybrid nanofibers are sensitive to selected solvents (acetone, methanol and THF) and present positive response making them good candidates for the production of VOC sensors.
The feasibility of using commercially available anionic polymerizable surfactants (LatemulPD‐104 and SipomerPam‐200) and anionic polymerizable stabilizer (SipomerCops‐1) in the batch emulsion copolymerization of model acrylic latexes is studied. The effect of both surfactant type and surfactant concentration on the number of polymer particles and molecular weights is investigated. LatemulPD‐104 behaves as the conventional surfactant Dowfax2A1 and the dependence of the number of particles upon surfactant concentration is similar for both surfactants. However, when SipomerPam‐200 is used a higher dependence is observed, probably due to a substantial contribution of homogeneous nucleation. When the stabilizer SipomerCops‐1 is used polymer particles are only formed by homogeneous nucleation. The molecular weights of the final latexes are affected by the surfactant type and concentration used in the polymerization, and unexpectedly, gel is formed when SipomerPam‐200 is used.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.