Dynamic Mechanical and Dielectric Behavior of Erucamide (13-Cis-Docosenamide), Isotactic Poly(propylene), and Their Blends I. QUIJADA-GARRIDO, 1 J. M. BARRALES-RIENDA, 1 J. M. PEREN ˜ A, 1 G. FRUTOS 2 1 Departamento de Qui ´ mica–Fi ´ sica de Poli ´ meros, Instituto de Ciencia y Tecnologi ´ a de Poli ´ meros, Juan de la Cierva, 3, E-28006 Madrid, Spain 2 Departamento de Estadi ´ stica e Investigacio ´ n Operativa, Facultad de Farmacia, Universidad Complutense, E-28040 Madrid, Spain Received 6 June 1996; revised 31 January 1997; accepted 7 February 1997 ABSTRACT: Blends of erucamide ( 13-cis-docosenamide ) and isotactic poly ( propylene ) were analyzed by means of dynamic mechanical (at 3, 10, and 30 Hz) and dielectric (at 1, 6, and 20 kHz) techniques. The dependence of tan d with temperature for each one of the blends has been fitted to Gaussian functions in order to deconvolute the overlapped relaxations. Three relaxations for i-PP, a i-PP , b i-PP , g i-PP , three for erucamide, a ERU , b ERU , and g ERU , and five for their blends have been observed and assigned. They do not vary appreciably with composition, suggesting that the components are incompatible either as globules in the matrix or in the amorphous regions of the spheru- lites, and / or in their surroundings.  1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1473 – 1482, 1997 Keywords: poly ( propylene ) ; erucamide; erucamide / poly ( propylene ) blends; dynamic mechanical relaxations; dielectric relaxations INTRODUCTION pletely controlled. Quijada – Garrido et al. 3 have determined under different thermal and time con- ditions the diffusion coefficients of erucamide ( 13- Slip agents are now very common products used cis-docosenamide ) into i-PP. They have interpre- as additives in the preparation of polyolefin films ted the diffusion or migration of erucamide to modify surface properties and, therefore, to fa- through i-PP by means of a semiempirical dual cilitate the release of two overlying layers during mechanism, in which two simultaneous Fickian use. 1 Long-chain aliphatic amides, mostly ole- processes are involved. This fact prompted Qui- amide and erucamide, are generally used. 2 Additi- jada–Garrido et al. 4 to carry out DSC studies on vated isotactic propylene ( i-PP ) containing fatty blends prepared by dry mixing. They have demon- acid amides or some other additives with chemi- strated that crystallization of erucamide / i-PP cally modified structures are of ever-increasing blends results in separate crystals of the two com- interest as slip and antiblock agents because both ponents rather than cocrystallization. For low their diffusion and surface properties can be com- content erucamide blends (less than 29%), two melting peaks for erucamide were found. They were assigned to: ( 1 ) erucamide crystals situated Correspondence to: J. M. Barrales – Rienda Contract grant sponsor: DCICYT; contract grant number: in the external surfaces of the i-PP and located PB 92–0773–03–1, and PB 95–0134–002–00 forming globules or inclusions that appear at the Contract grant sponsor: CICYT; contract grant number: higher temperature (ERUCAMIDE I), and (2) MAT 94–0858-E  1997 John Wiley & Sons, Inc. CCC 0887-6266/97 / 101473-10 erucamide crystals located probably in the amor- 1473 9606011 / 8q2e$$6011 05-21-97 00:15:20 polpa W: Poly Physics