Thermal and dynamic mechanical analysis on metallocene ULDPE/PP blends to optimize impact properties

Citation
Ar. Khare et al., Thermal and dynamic mechanical analysis on metallocene ULDPE/PP blends to optimize impact properties, THERMOC ACT, 357, 2000, pp. 155-160
Citations number
7
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
THERMOCHIMICA ACTA
ISSN journal
0040-6031 → ACNP
Volume
357
Year of publication
2000
Pages
155 - 160
Database
ISI
SICI code
0040-6031(20000814)357:<155:TADMAO>2.0.ZU;2-C
Abstract
Metallocene polymerized ultralow density polyethylenes (ULDPE) were found t o be effective impact modifiers for rigid matrices such as polypropylene (P P). This is mainly due to the very high level of comonomer incorporation wi th homogeneous short chain branching distributions (SCBD) brought about by the single site metallocene catalysts. However, a very heterogeneous Ziegle r Natta copolymer of 0.88 specific gravity was found to be surprisingly eff ective in impact modification efficiency. A variety of thermal and morphological techniques were used in this study i ncluding differential scanning calorimetry (DSC), dynamic mechanical analys is (DMA), and low voltage scanning electron microscopy (LVSEM). It was foun d that the modulus difference between the two phases, degree of coupling as evidenced by morphology at the phase boundaries, and crystallizable fracti on of the rubber phase all played an important role in impact modification. (C) 2000 Elsevier Science B.V. All rights reserved.