| abstract |
A block copolymer consisting essentially of crystalline polymerized propylene segments joined to crystalline segments of polymerized alpha -mono-olefinic hydrocarbon other than propylene. These block copolymers have an inherent viscosity in Tetralin at 145 DEG C. of from about 0.4 to 2.4, a density of at least 0.85, a brittle point below 0 DEG C. and contain at least 80 percent, by weight, of polymerized propylene. |