Ethylene propylene diene terpolymers produced with a homogeneous and highly active zirconium catalyst

Show full item record

Title: Ethylene propylene diene terpolymers produced with a homogeneous and highly active zirconium catalyst
Author: Kaminski, Walter; Miri, Massoud
Abstract: EPDM terpolymers with ethylidene norbornene as diene monomer could be prepared by means of a soluble Ziegler catalyst formed from biscyclopentadienyl zirconium dimethyl and methylaluminoxane. The overall activities lie between 100 and 1000 kg EPDM/(molZr h bar), obtainable at zirconium concentrations as low as 5 × 10-7 mol/L. After an induction period (0.5-5 h) the polymerization rates increased and then leveled to a value which was constant for several days. From copolymerization kinetics reactivity ratios r12 = 31.5, r21 = 5 × 10-3, and r13 = 3.1 could be derived, and by 13C-NMR spectroscopy r12 · r21 = 0.3 was found (1: ethylene, 2: propylene and 3: ethylidene norbornene). The regiospecifity of the catalyst toward propylene leads exclusively to the formation of head-to-tail enchainments. The diene polymerizes via vinyl polymerization of the cyclic double bond, and the tendency to branching is low. Molecular weights were estimated between 40,000 and 160,000. The average molecular weight distribution of 1.7 is remarkably narrow. Glass transition temperatures of -60 to -50°C could be observed. The cure behavior and the physical properties of cured samples were also tested.
Record URI: http://hdl.handle.net/1850/2175
Publishers URL: http://dx.doi.org/10.1002/pol.1985.170230807
Date: 1985-08

Files in this item

Files Size Format View

An open access version of this file is not available. Check "Publisher URL" field for access

This item appears in the following Collection(s)

Show full item record

Search RIT DML


Advanced Search

Browse