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The effect of relative humidity on the curing of alkoxysilane functional alkyds and reactive diluents was evaluated. Alkoxysilane functional alkyds and tung oil-based reactive diluents were synthesized and used as additives in varying amounts in alkyd coatings. Looking at modified alkyd versus modified reactive diluent allows for the comparison of the humidity effect on high and low molecular weight alkoxysilane functional additives. The coatings were cured at 25 and 75% relative humidity and evaluated for drying time, coating and tensile properties, and gel content. It was found that at higher humidity, the alkoxysilane-containing samples improved properties significantly when compared to the control alkyd.

Alkoxysilane modified linseed oil alkyds (TESLOA) were prepared using 3-(triethoxysilyl)propyl isocyanate (TESPIC). TESLOA was formulated as a high solids coating substituting up to 40% of an unmodified long oil linseed oil alkyd in increments of 10%. All the resulting high solids alkyds had a viscosity below 5000 cP. Toxicity and volatile organic compounds (VOCs) were reduced using an iron based primary drier and VOC-exempt acetone, respectively. An increase in adhesion was observed when TESLOA was used in formulations. The chemical resistance, appearance, and flexibility were examined using standard coating tests. An increase in chemical resistance and hardness was observed, while maintaining the flexibility and appearance. The surface energy was measured using contact angle. The TESLOA surface energy exhibited a hydrophobic shift in terms of surface wetting. The additional crosslinking sites of the TESLOA alkyds were evident in a higher glass transition temperature and crosslink density. Tensile properties also exhibited an increase in modulus. Fracture toughness testing showed up to a 50% increase in stress intensity factor at fracture, KIC, and the elastic energy release rate, GIC, when 20 wt.% of TESLOA in the formulation. Corrosion protection was studied using electrochemical impedance spectroscopy (EIS). The EIS data suggested that some self-healing properties could be obtained when using TESLOA as an additive.

A high solids alkyd coating was developed with surface active polymers to improve performance at the surface, while maintaining adhesion at the substrate. A fluorinated long oil alkyd (FLOA) was prepared through a partial polyol substitution of 2,2,3,3,4,4,5,5-octafluoro-1,6- hexanediol for glycerol with phthalic anhydride and linseed oil in a long oil alkyd (LOA). A previously synthesized fluorinated tung oil (FTO) reactive diluent was also synthesized via a Diels- Alder reaction with 2,2,2-trifluoroethyl methacrylate. The alkyd and reactive diluent were characterized with 1H-NMR and MALDI-TOF mass spectroscopy. The FLOA was used as an additive up to 40 wt.% of the total alkyd, in increments of 10 wt.%. The FTO was used as an additive up to 10 wt.% of the total alkyd, in increments of 2.5 wt.%. The film formation was examined using scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDX) to show phase separation and domains of the low surface energy additive. Analysis of a cross-section of the coating showed an increase in fluorine concentration of 40% at the surface, compared to substrate, which preserves adhesion. A variety of coatings tests were performed to evaluate hardness, adhesion, mechanical strength and flexibility of the coating. The contact angle of FLOA/FTO coatings shifted from hydrophilic to hydrophobic surface energy. An increase in corrosion protection for FLOA/FTO coatings was evaluated using electrochemical impedance spectroscopy (EIS).

The hydrolytic stability was evaluated for a series of oligoesters comprised of three or four different monomers. The oligoesters were prepared from adipic acid (AA) and isophthalic acid (IPA) with six different diols, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-butene-1,4-diol, and one triol, trimethylolpropane. The hydroxyl-terminated ternary and quaternary oligoesters were end-capped using phenyl isocyanate. The hydrolysis rate constants were obtained from acid number. The flexibility of diacids had a determinative effect on the hydrolytic stability of the carbamate end-capped oligoesters.

Four model alkyds were prepared by the fatty acid process using a single fatty acid (stearic, oleic, linoleic, or linolenic acid) with phthalic anhydride and glycerol. These model alkyds were react...

We report on the synthesis and characterization of bent‐core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI‐AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmCaPA phase down to below −40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterized and their liquid crystal as well as electro‐optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X‐ray diffraction, dielectric spectroscopy, and electro‐optical tests.

The Inside Cover picture highlights how an optically isotropic antiferroelectric liquid‐crystal display mode can be accomplished by using ternary bent‐core liquid crystal mixtures operating from well below room temperature up to 100 °C. More details can be found in the Communication by T. Hegmann and co‐workers on page 196 in Issue 2, 2017 (DOI: 10.1002/open.201600138).