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In this study, we describe the synthesis of amides and evaluate their use as slip additive agents in polypropylene films. The additives N-isopropyl-stearamide and N,N-diisopropyl-stearamide were synthesized and characterized and then used to prepare masterbatches. Erucamide, a commercial masterbatch, was used as the reference standard. A 32factorial experimental design was used to create the different compositions of slip additives in polymer films. The films were processed via flat-die extrusion and stored in an oven at a constant temperature of 40 °C for seven days. The following are the properties evaluated in the study: thermal decomposition temperature, fusion temperature, fusion enthalpy, coefficient of friction, surface energy, contact angle, and seal initiation temperature. The results were evaluated by analysis of variance (ANOVA) at a 90 % confidence interval. The analysis of the results showed that N-isopropyl stearamide and N,N-diisopropyl stearamide do not provide an adequate surface slip for polypropylene films at the conditions used in the study. In turn, at the same conditions, erucamide, the commercial amide, also does not provide the required surface energy for printing and lamination processes required for polypropylene films.

This research evaluates the effects of molecular weight, polymer solution concentration, and carbon nanotube concentration on diameter distribution of polymer nanofibers produced with gas jet fiber (GJF) method. In GJF method, the shear and extensional forces of high-velocity gas jets are used to spin fibers from polymer solutions. The correlation between polymer molecular weight and fiber diameter distribution is studied along with the effect of multi-walled carbon nanotubes (MWCNT) on fiber diameter distribution. The paper also assesses how carbon nanotubes distribute in bi-component polymer nanofibers. It is found that polymer chain entanglement is a key determinant of fiber diameter. MWCNTs do not show preference for distribution in polyvinylidene pyrrole (PVP) and polyvinylacetate (PVAc) and instead appear on the surfaces of the fibers. A negative value of spreading coefficient supports this observation.

High‐density polyethylene was irradiated with ultraviolet light for various exposure times, as a prestep for hydroperoxide production, before a bulk grafting reaction with maleic anhydride in the melt phase by reactive extrusion. This method was compared with a traditional grafting procedure using peroxides optimized by an evaluation of the grafting level versus the screw speed; the highest speed showed the greatest grafting value. The reaction was followed by Fourier transform infrared, the gel percentage, and the grafting degree, which was evaluated by titration. The effect of grafting for both methods under the established processing conditions on the thermal properties was observed with differential scanning calorimetry via their heating and cooling thermograms; there were notorious changes in the fusion peak temperatures, indicating differences in the crystallization process after the grafting reaction. The latter was confirmed by NMR spectroscopy, which showed succinic anhydride rings attached to the polyethylene chains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2882–2888, 2006

Summary: PVC stabilised with mixtures of pre-heated metal stearates are degraded thermally for specific periods of time, in order to determine their influence on the production of polyenes by uv spectroscopy. Additionally, the PVC samples are treated with NaBH4 to reduce the carbonylic groups produced during the thermo-oxidative process. Important differences in the polyene formation trends are observed, between the reduced and non-reduced samples, indicating that the carbonyl groups attached to polyenes shift the absorbance maxima and alter considerably the quantification of the double bond conjugations.

Continuing with the evaluation of costabilizers along with preheated metal stearates to stabilize poly(vinyl chloride) (PVC), pentaerythritol was chosen as a long-term costabilizer. During normal stabilization conditions, the polyol enhances the induction time to degradation but produces large amounts of polyenes. The use of the preheated mixture of metal soaps and preheated ZnSt2 enhanced even more such times, while preheated CaSt2 reduced them. The same effect was seen with the β-diketone; and, as in that case, the results seems to be the sum of both separated effects. Evaluations of induction times to degradation, carbonyl formation, visible reflectance, and UV-visible and fluorescence spectroscopic techniques support these findings. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:11–27, 1998

The influence of a β-diketone on the already observed anomalous behavior of preheated metal stearates as stabilizers for PVC has been evaluated. During normal stabilization procedure, the addition of diketones reduce the stabilization times, but the pretreatment of the mixture of metal soaps or of the individual zinc soap (then added to the calcium soap) delayed such times, recovering to some extent the reduction induced by the costabilizer. The calcium soap preheated (added along with zinc stearate to PVC), on the other hand, reduced the induction times further. These findings obtained by measurement of induction times by means of loss of weight (TGA) and HCl evolution, have been supported by FTIR and visible reflectance studies. While using preheated ZnSt2, a second rate of dehydrochlorination was observed in the HCl evolution traces, suggesting a separate consumption of the compounds during the stabilization mechanism. In general, it can be said that preheated primary stabilizers and costabilizers have no significant interactions between them. The final result is just the addition of their separate effects. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:1–10, 1998