provided herein are propylene polymers which are capable of being used as thermoplastic polyolefins just as they emerge from the reactor system described , without further compounding of components which substantially modify the physical properties of the polymers , as such compounding is required of polymers of the prior art . polymers according to the invention unexpectedly possess both low temperature ductility and high flexural modulus , which properties were related in inverse proportion to one another in the polymers of the prior art .