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Copolymerizations of propene with higher a-olefins including 1 -butene, 1 -hexene, 1 -octene, 1 -dodecene and 1 -hexadecene were carried out with an isospecific metallocene catalyst (Et[Ind],HfCl,/methylaluminoxane) at 30 "C in toluene. 13C NMR analysis showed that all products obtained are random copolymers (rl * rz = 1). The reactivity of the higher a-olefins in the copolymerization is surprisingly high and decreases only slightly with increasing length of the olefin. The incorporation rates of the comonomers in this study were found to be much higher than those obtained by the use of heterogeneous Ziegler-Natta catalysts. Hence, copolymers with every desired composition and a-olefin homopolymers can be prepared. The molecular weight of the copolymers is reduced with rising comonomer content. Melting points and glass transition temperatures studied by means of differential scanning calorimetry show a decrease with rising comonomer content and increasing length of the a-olefin.

The phase behavior of poly(styrene-b-butyl methacrylate), PS-b-PBMA, diblock copolymers was investigated by small-angle neutron scattering (SANS), neutron reflectometry (NR), and rheology. For a symmetrical P(dS-b-nBMA) diblock copolymer a lower critical order transition (LCOT) at 155°C was found by SANS and rheology. Furthermore, the temperature-dependent interaction parameter was determined in the temperature regime between 110 and 145°C from fits to the scattering curves in the disordered region. The interaction parameter increases with increasing temperature and shows a weak temperature dependence. The LCOT behavior thus is expected to be a large entropic contribution to . The interfacial width observed by NR is relatively large compared to other diblock copolymers. Different block copolymers were investigated with respect to the influence of miscibility on tensile properties. While poly(styrene-b-butyl methacrylate) diblock copolymers show significant synergistic effects on tensile properties, for poly(methyl methacrylate-b-butyl methacrylate) diblock copolymers no significant synergistic effects on tensile properties were observed due to the increased interaction parameter and the smaller interfacial width as compared to the case of PS-b-PBMA diblock copolymers.