Dental waxes are often a blend of several waxes that are necessary to develop the most desirable qualities. In general, more information is available on physical properties and manipulation of dental waxes than on the composition or nature of the ingredients. Since heats of transition are fundamental in characterizing the chemical nature of matter, this information was obtained from waxes and b...

Waxes used in dentistry are combinations of two or more natural waxes plus small amounts of additives, such as oils, natural resins, synthetic waxes, and coloring agents. The ultimate goal of the combination of waxes and additives is to produce dental waxes that possess a set of given physical properties over a specified range of temperature. Although considerable effort has been expended to de...

Curvularia eragrostidis, a causal agent of head blight on the weed (Digitaria sanguinalis), did not cause disease on the turfgrass Festuca arundinacea. Different extracellular esterase isoenzymes were detected in saprophytic and parasitic phases during the fungal germination. The epicuticular waxes of D. sanguinalis were more efficient to induce the secretion of esterases from the fungus than t...

The characterization of waxes by differential thermal analysis is described. An endothermic peak at 475-480 degrees is characteristic of microcrystalline and polyethylene waxes, and measurement of its area provides a method for the estimation of these waxes in mixtures.

The interface between plants and the environment is provided for aerial organs by epicuticular waxes that have been extensively studied. By contrast, little is known about the nature, biosynthesis, and role of waxes at the root-rhizosphere interface. Waxes isolated by rapid immersion of Arabidopsis (Arabidopsis thaliana) roots in organic solvents were rich in saturated C18-C22 alkyl esters of p...

Ten dental impression waxes were characterized by penetration and differential thermal analysis. Penetration and initial transition temperatures were directly correlated. Penetration at 37 C ranged from 2.5 to 22% for bite waxes and was 100% for corrective waxes. Distortion of an impression wax may occur upon removal from the mouth.

Plants prevent dehydration by coating their aerial, primary organs with waxes. Wax compositions frequently differ between species, organs, and developmental stages, probably to balance limiting nonstomatal water loss with various other ecophysiological roles of surface waxes. To establish structure-function relationships, we quantified the composition and transpiration barrier properties of the...

Excess specific heat, C(p)()(E), of binary mixtures of selected components of plant cuticular waxes has been determined. This thermodynamic parameter gives an explanation of the special molecular arrangement in crystalline and amorphous zones of plant waxes. C(p)()(E) values indicate that hydrogen bonding between chains results in the formation of amorphous zones. Conclusions on the self-asembl...