A staple of science fiction in the recent decades is the notion of "plasteel", that is, (presumably) an organic polymer or a combination of such polymers possesing enough tensile strength, hardness, resistance to corrosion/heat and so on to be a viable substitute for metal (or concrete) in certain types of construction and manufacturing. Now, having studied a course or two in organic chemistry at the college, I know that contemporary technology allows the production of a wide variety of hydrocrbon-based polimers, with greatly varying characteristics, up to and including adding good electric conductivity to plastics; however, in terms of material engineering I'm far less educated. My question is: is there today, or could it be projected in the near future with the required characteristics to be "plasteel", "plascrete" or "densiplast" as portraid in common sci-fi?