Polymerisation of acetylene derivatives. III. Polymerisation of a dimer of 4-penten-2-yn-1-ol and attempted polymerisation and copolymerisation with styrene of 1:1:3:3:6-pentamethyl-4-isopropenyliso-coumaran, 1: 4 - di -p - chlorophenoxy - 2 - butyne, and