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This paper is dedicated to Professor Arthur S . Perlin on the occasion of his 67th birthdayDENIS DUCHESNE and ADI EISENBERG. Can. J . Chem. 68, 1228 (1990). The thermal and dynamic mechanical properties of random butyl acrylate-and plasticized ethyl acrylate-based vinylpyridinium ionomers have been investigated. The properties of the ionomers were found to be dependent on the glass transition temperature of the matrix material. Ionomers having a glass transition temperature lower than ca. 25°C exhibited all the features associated with the presence of phase-separated microdomains or clusters while the materials with higher glass transition temperatures were not. It was also observed that the dispersion associated with the vinylpyridinium clusters for a butyl acrylate-based ionomer with 12 mol% of ionic units occurs at ca. 25'C. This value is very close to that observed previously by Otocka and Eirich in their study of a butadiene-based vinylpyridinium ionomer with the same ion content.Key words: ionomers, plasticization, clustering, glass transition, dynamic mechanical properties.DENIS DUCHESNE et ADI EISENBERG. Can. J. Chem. 68, 1228 (1990). On a examint les propriCtts dynamiques et mtcaniques d'ionomeres du vinylpyridinium bases sur de l'acrylate de butyle et de I'acrylate d'Cthyle plastifit. On a trouvC que les proprittts des ionomeres dtpendent de la temperature de transition vitreuse du mattriel de la matrice. Les ionomeres posstdant une temperature de transition vitreuse inferieure a environ 25°C prtsentent toutes les caracttristiques assocites a la prtsence des microdomaines ou des agrtgats stparts par des phases; ce n'est pas le cas avec les mattriaux dont les temptratures de transition vitreuse sont plus tlevtes. On a aussi observt que la dispersion associte aux agrtgats de vinylpyridinium d'un ionomere bast sur I'acrylate de butyle et contenant 12 mol% d'unitts ioniques se produit a environ 25°C. Cette valeur est tres semblable de celle observCe anttrieurement par Otocka et Eirich dans leur ttude d'un ionomhe de vinylpyridinium bast sur le butadiene et contenant la m&me quantitt d'ion.

Anti-block agents differing in composition, structure, and surface coating were compounded with fluorocarbon elastomer polymer processing aids (PPAs) in linear low density polyethylene. Separate and combined masterbatches of 20% anti-block and 2% PPA were melt mixed and let down to 5000 ppm and 500 ppm respectively. Preliminary investigation of the combined PPA/anti-block masterbatches by capil lary rheometer identified wide ranging differences when comparing equilibrium melt viscosity and melt fracture onset. Synthetic silicas appeared to show the great est decrease in PPA performance while ceramic micro-spheres caused little change. Further studies were conducted on a commercial film line at shear rates of 750 s-1. Results showed that the PPA was generally more effective when incorporated as a separate masterbatch than when compounded with the anti-block. For example, melt fracture could only be eliminated in the presence of diatomaceous earth and the PPA when the two were compounded separately. In the case of calcium carbonate and ceramic spheres, melt fracture was eliminated in the combined samples but equilib rium pressures were higher and equilibrium times were longer. Coated silicas showed less interference with PPA performance than did their uncoated analogs when used in a combined masterbatch.

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