Erucamide solubility

The concentration of additive on the surface is controlled by diffusion constant and temperature. Diffusion constant of erucamide in polypropylene had linear relationship with temperature, which permitted calculation of activation eneigy of 100 kJ/mol. Solubility of emcamide in polypropylene differs above and below its melting point. Above the melting point erucamide solubility in polypropylene is temperature independent and it decreases with temperature decreasing below the melting point of erucamide. ... 

PVAc has been determined according to equation Tg = 18.4 - 6.77C + 0.2197C (plasticiser content C in % validity range 0-12.5% correlation coefficient 0.9986) [85]. Whereas further chlorinating (PVCC) increases Tg from approximately 86°C towards 100°C, it can be lowered to almost any value by addition of plasticisers (-40° to +90°C), as indeed is true also for PVAc. When the additive concentration in a resin exceeds a few weight percent, it is often possible to assay the additive calorimetri-cally without extracting it. If the additive is incompatible with the resin, it can be detected in a separate crystalline or glassy phase by either its Tm or Tg and measured quantitatively from A7/f determinations at Tin or Acp measurements at Tg. When an additive is soluble in a polymer, its concentration can be estimated from shifts in Tm or Tg of the resin. Once a master curve of Tg V5. plasticiser concentration has been prepared for a particular PVC composition, it can be used to determine the amount of plasticiser in an unknown formulation of the particular plasticiser, e.g. PVC/DIDP (cfr. Fig. 2.1) [27]. For PVC/DOP a linear relationship from zero to 45 wt.% plasticiser has been reported [86]. DSC was also used in miscibility studies of erucamide and PA 12 [87]. 

Figure 6.1. Solubility of erucamide in polypropylene and ethylene-propylene copolymer vs. temperature. [Adapted, by permission from Kefaleas, C. Billingham, N. C., Polym. Preprints, 42,1, 350-1,2001.]...

Behenamide, on the other hand, lacking the carbon-carbon unsaturation found in erucamide, is substantially less soluble in the alcohols and ketones found in printing inks. Thus, when, in the course of rotogravure printing, some of the behenamide is deposited on the printing cylinder, it is not dissolved in the printing ink and wiped off when the next application of ink and wiping by the doctor blade takes place. As a result, the behenamide is merely wiped off by the next swipe of the doctor blade and substantially all of it remains on the blade. After multiple... 

Above the melting point of erucamide (80°C 1/T=2.83) there is no effect of temperature on solubility of erucamide in any of the two polymers. Because heat of fusion in this region is equal zero, then the first term also equals zero and this implies that above the melting point erucamide forms ideal solution. Since solubility is constant also interaction parameter, x, is temperature independent above the melting point of erucamide. 

Solubility of erucamide in EP is lower than for PP that is not according to expectations considering that higher free volume and lower crystallinity of EP in comparison with PP should result in opposite effect on solubility. 

In the rotogravure process, ink is applied to the print surface from a gravure cylinder containing the desired image as depressions on its surface. The film to be printed is then contacted by the gravure cylinder and the image is thus transferred from the cylinder to the film. While the film is in contact with the cylinder, a small amount of erucamide is deposited on the raised portion of the cylinder. Since erucamide is soluble in the alcohol or ketone ink solvent, it is dissolved by the solvent in the next application of ink and it is removed by the next swipe of the doctor blade. Thus, no build-up of erucamide occurs on the doctor blade or on the gravure cylinder. ... 

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