SYNTHESIS AND CHARACTERIZATION OF BUTADIENE ETHENE PROPENE TERPOLYMERS

Butadiene/ethene/propene terpolymers are synthesized by Ziegler-Natta polymerization with the catalyst system VO(O-neopentyl)2Cl/Al(i-Bu)3 in toluene at - 10-degrees-C. Variation of the amounts of propene and ethene leads to products with propene contents between 5 and 30 mol-% (referring to monomeric unit) in the polymer. These polymers are terpolymers with alternating units of butadiene-ethene and butadiene-propene sequences as shown by means of nuclear magnetic resonance investigations. The degree of crystallinity can be varied between 10 and 51 mol-% by different incorporation of propene into the terpolymer (X-ray diffraction). The thermal behaviour was characterized using differential scanning calorimetry investigations. Depending on the propene content in the terpolymer the degree of crystallinity significantly influences the parameters of glass transition and the melting process.