Direct metathesis copolymerization

Ring-opening metathesis copolymerizations of cyclooctene and norbomyl-POSS were performed with Grubbs s catalyst, RuCl2(=CHPh)(PCy3)2 (Fig. 11). Reduction of these copolymers afforded poly(ethylene-co-norbomyl-POSS) copolymers, which have properties similar to those of the poly(ethylene-co-norbomylethyl-POSS) prepared by direct copolymerization of ethylene with no bomyl-POSS, described above. Poly(cyclooctene-co-norbornylethyl-POSS) copolymers with 0,12,23,31,45, and 56 wt % POSS (0,1.39,3.06,4.62, 7.96, and 11.9 mol %) had melting temperatures of 46°C, 43°C, 38°C, 36°C, 33°C, and 30°C, respectively. Their heat of fusion values (J/g) are 56,45,36,28, 24, and 19, respectively. This decrease in both melting temperatures and heat of fusion values as more POSS is incorporated shows that the random POSS moieties disrupted crystallinity. No Tg was observed for these copolymers, presumably because of their semicrystalline nature. 

---